{"id":647,"date":"2019-05-20T08:45:50","date_gmt":"2019-05-20T00:45:50","guid":{"rendered":"http:\/\/www.hefeiyu.com\/?p=647"},"modified":"2019-05-20T08:46:06","modified_gmt":"2019-05-20T00:46:06","slug":"oracle%e6%95%b0%e6%8d%ae%e5%ba%93%e6%80%a7%e8%83%bd%e4%bc%98%e5%8c%96%e4%b9%8bsql%e8%af%ad%e5%8f%a5%e4%bc%98%e5%8c%96","status":"publish","type":"post","link":"https:\/\/www.hefeiyu.com\/?p=647","title":{"rendered":"ORACLE\u6570\u636e\u5e93\u6027\u80fd\u4f18\u5316\u4e4bSQL\u8bed\u53e5\u4f18\u5316"},"content":{"rendered":"

\u4e00\u3001\u95ee\u9898\u7684\u63d0\u51fa<\/p>\n

\u5728\u5e94\u7528\u7cfb\u7edf\u5f00\u53d1\u521d\u671f\uff0c\u7531\u4e8e\u5f00\u53d1\u6570\u636e\u5e93\u6570\u636e\u6bd4\u8f83\u5c11\uff0c\u5bf9\u4e8e\u67e5\u8be2SQL\u8bed\u53e5\uff0c\u590d\u6742\u89c6\u56fe\u7684\u7684\u7f16\u5199\u7b49\u4f53\u4f1a\u4e0d\u51faSQL\u8bed\u53e5\u5404\u79cd\u5199\u6cd5\u7684\u6027\u80fd\u4f18\u52a3\uff0c\u4f46\u662f\u5982\u679c\u5c06\u5e94\u7528\u7cfb\u7edf\u63d0\u4ea4\u5b9e\u9645\u5e94\u7528\u540e\uff0c\u968f\u7740\u6570\u636e\u5e93\u4e2d\u6570\u636e\u7684\u589e\u52a0\uff0c\u7cfb\u7edf\u7684\u54cd\u5e94\u901f\u5ea6\u5c31\u6210\u4e3a\u76ee\u524d\u7cfb\u7edf\u9700\u8981\u89e3\u51b3\u7684\u6700\u4e3b\u8981\u7684\u95ee\u9898\u4e4b\u4e00\u3002\u7cfb\u7edf\u4f18\u5316\u4e2d\u4e00\u4e2a\u5f88\u91cd\u8981\u7684\u65b9\u9762\u5c31\u662fSQL\u8bed\u53e5\u7684\u4f18\u5316\u3002\u5bf9\u4e8e\u6d77\u91cf\u6570\u636e\uff0c\u52a3\u8d28SQL\u8bed\u53e5\u548c\u4f18\u8d28SQL\u8bed\u53e5\u4e4b\u95f4\u7684\u901f\u5ea6\u5dee\u522b\u53ef\u4ee5\u8fbe\u5230\u4e0a\u767e\u500d\uff0c\u53ef\u89c1\u5bf9\u4e8e\u4e00\u4e2a\u7cfb\u7edf\u4e0d\u662f\u7b80\u5355\u5730\u80fd\u5b9e\u73b0\u5176\u529f\u80fd\u5c31\u53ef\uff0c\u800c\u662f\u8981\u5199\u51fa\u9ad8\u8d28\u91cf\u7684SQL\u8bed\u53e5\uff0c\u63d0\u9ad8\u7cfb\u7edf\u7684\u53ef\u7528\u6027\u3002<\/p>\n

\u5728\u591a\u6570\u60c5\u51b5\u4e0b\uff0cOracle\u4f7f\u7528\u7d22\u5f15\u6765\u66f4\u5feb\u5730\u904d\u5386\u8868\uff0c\u4f18\u5316\u5668\u4e3b\u8981\u6839\u636e\u5b9a\u4e49\u7684\u7d22\u5f15\u6765\u63d0\u9ad8\u6027\u80fd\u3002\u4f46\u662f\uff0c\u5982\u679c\u5728SQL\u8bed\u53e5\u7684where\u5b50\u53e5\u4e2d\u5199\u7684SQL\u4ee3\u7801\u4e0d\u5408\u7406\uff0c\u5c31\u4f1a\u9020\u6210\u4f18\u5316\u5668\u5220\u53bb\u7d22\u5f15\u800c\u4f7f\u7528\u5168\u8868\u626b\u63cf\uff0c\u4e00\u822c\u5c31\u8fd9\u79cdSQL\u8bed\u53e5\u5c31\u662f\u6240\u8c13\u7684\u52a3\u8d28SQL\u8bed\u53e5\u3002\u5728\u7f16\u5199SQL\u8bed\u53e5\u65f6\u6211\u4eec\u5e94\u6e05\u695a\u4f18\u5316\u5668\u6839\u636e\u4f55\u79cd\u539f\u5219\u6765\u5220\u9664\u7d22\u5f15\uff0c\u8fd9\u6709\u52a9\u4e8e\u5199\u51fa\u9ad8\u6027\u80fd\u7684SQL\u8bed\u53e5\u3002<\/p>\n

\u4e8c\u3001SQL\u8bed\u53e5\u7f16\u5199\u6ce8\u610f\u95ee\u9898<\/p>\n

\u4e0b\u9762\u5c31\u67d0\u4e9bSQL\u8bed\u53e5\u7684where\u5b50\u53e5\u7f16\u5199\u4e2d\u9700\u8981\u6ce8\u610f\u7684\u95ee\u9898\u4f5c\u8be6\u7ec6\u4ecb\u7ecd\u3002\u5728\u8fd9\u4e9bwhere\u5b50\u53e5\u4e2d\uff0c\u5373\u4f7f\u67d0\u4e9b\u5217\u5b58\u5728\u7d22\u5f15\uff0c\u4f46\u662f\u7531\u4e8e\u7f16\u5199\u4e86\u52a3\u8d28\u7684SQL\uff0c\u7cfb\u7edf\u5728\u8fd0\u884c\u8be5SQL\u8bed\u53e5\u65f6\u4e5f\u4e0d\u80fd\u4f7f\u7528\u8be5\u7d22\u5f15\uff0c\u800c\u540c\u6837\u4f7f\u7528\u5168\u8868\u626b\u63cf\uff0c\u8fd9\u5c31\u9020\u6210\u4e86\u54cd\u5e94\u901f\u5ea6\u7684\u6781\u5927\u964d\u4f4e\u3002<\/p>\n

1. \u64cd\u4f5c\u7b26\u4f18\u5316<\/p>\n

(a) IN \u64cd\u4f5c\u7b26<\/p>\n

\u7528IN\u5199\u51fa\u6765\u7684SQL\u7684\u4f18\u70b9\u662f\u6bd4\u8f83\u5bb9\u6613\u5199\u53ca\u6e05\u6670\u6613\u61c2\uff0c\u8fd9\u6bd4\u8f83\u9002\u5408\u73b0\u4ee3\u8f6f\u4ef6\u5f00\u53d1\u7684\u98ce\u683c\u3002\u4f46\u662f\u7528IN\u7684SQL\u6027\u80fd\u603b\u662f\u6bd4\u8f83\u4f4e\u7684\uff0c\u4eceOracle\u6267\u884c\u7684\u6b65\u9aa4\u6765\u5206\u6790\u7528IN\u7684SQL\u4e0e\u4e0d\u7528IN\u7684SQL\u6709\u4ee5\u4e0b\u533a\u522b\uff1a<\/p>\n

ORACLE\u8bd5\u56fe\u5c06\u5176\u8f6c\u6362\u6210\u591a\u4e2a\u8868\u7684\u8fde\u63a5\uff0c\u5982\u679c\u8f6c\u6362\u4e0d\u6210\u529f\u5219\u5148\u6267\u884cIN\u91cc\u9762\u7684\u5b50\u67e5\u8be2\uff0c\u518d\u67e5\u8be2\u5916\u5c42\u7684\u8868\u8bb0\u5f55\uff0c\u5982\u679c\u8f6c\u6362\u6210\u529f\u5219\u76f4\u63a5\u91c7\u7528\u591a\u4e2a\u8868\u7684\u8fde\u63a5\u65b9\u5f0f\u67e5\u8be2\u3002\u7531\u6b64\u53ef\u89c1\u7528IN\u7684SQL\u81f3\u5c11\u591a\u4e86\u4e00\u4e2a\u8f6c\u6362\u7684\u8fc7\u7a0b\u3002\u4e00\u822c\u7684SQL\u90fd\u53ef\u4ee5\u8f6c\u6362\u6210\u529f\uff0c\u4f46\u5bf9\u4e8e\u542b\u6709\u5206\u7ec4\u7edf\u8ba1\u7b49\u65b9\u9762\u7684SQL\u5c31\u4e0d\u80fd\u8f6c\u6362\u4e86\u3002<\/p>\n

\u63a8\u8350\u65b9\u6848\uff1a\u5728\u4e1a\u52a1\u5bc6\u96c6\u7684SQL\u5f53\u4e2d\u5c3d\u91cf\u4e0d\u91c7\u7528IN\u64cd\u4f5c\u7b26\uff0c\u7528EXISTS \u65b9\u6848\u4ee3\u66ff\u3002<\/p>\n

(b) NOT IN\u64cd\u4f5c\u7b26<\/p>\n

\u6b64\u64cd\u4f5c\u662f\u5f3a\u5217\u4e0d\u63a8\u8350\u4f7f\u7528\u7684\uff0c\u56e0\u4e3a\u5b83\u4e0d\u80fd\u5e94\u7528\u8868\u7684\u7d22\u5f15\u3002<\/p>\n

\u63a8\u8350\u65b9\u6848\uff1a\u7528NOT EXISTS \u65b9\u6848\u4ee3\u66ff<\/p>\n

(c) IS NULL \u6216IS NOT NULL\u64cd\u4f5c\uff08\u5224\u65ad\u5b57\u6bb5\u662f\u5426\u4e3a\u7a7a\uff09<\/p>\n

\u5224\u65ad\u5b57\u6bb5\u662f\u5426\u4e3a\u7a7a\u4e00\u822c\u662f\u4e0d\u4f1a\u5e94\u7528\u7d22\u5f15\u7684\uff0c\u56e0\u4e3a\u7d22\u5f15\u662f\u4e0d\u7d22\u5f15\u7a7a\u503c\u7684\u3002\u4e0d\u80fd\u7528null\u4f5c\u7d22\u5f15\uff0c\u4efb\u4f55\u5305\u542bnull\u503c\u7684\u5217\u90fd\u5c06\u4e0d\u4f1a\u88ab\u5305\u542b\u5728\u7d22\u5f15\u4e2d\u3002\u5373\u4f7f\u7d22\u5f15\u6709\u591a\u5217\u8fd9\u6837\u7684\u60c5\u51b5\u4e0b\uff0c\u53ea\u8981\u8fd9\u4e9b\u5217\u4e2d\u6709\u4e00\u5217\u542b\u6709null\uff0c\u8be5\u5217\u5c31\u4f1a\u4ece\u7d22\u5f15\u4e2d\u6392\u9664\u3002\u4e5f\u5c31\u662f\u8bf4\u5982\u679c\u67d0\u5217\u5b58\u5728\u7a7a\u503c\uff0c\u5373\u4f7f\u5bf9\u8be5\u5217\u5efa\u7d22\u5f15\u4e5f\u4e0d\u4f1a\u63d0\u9ad8\u6027\u80fd\u3002\u4efb\u4f55\u5728where\u5b50\u53e5\u4e2d\u4f7f\u7528is null\u6216is not null\u7684\u8bed\u53e5\u4f18\u5316\u5668\u662f\u4e0d\u5141\u8bb8\u4f7f\u7528\u7d22\u5f15\u7684\u3002<\/p>\n

\u63a8\u8350\u65b9\u6848\uff1a\u7528\u5176\u5b83\u76f8\u540c\u529f\u80fd\u7684\u64cd\u4f5c\u8fd0\u7b97\u4ee3\u66ff\uff0c\u5982\uff1aa is not null \u6539\u4e3a a>0 \u6216a>\u2019\u2019\u7b49\u3002\u4e0d\u5141\u8bb8\u5b57\u6bb5\u4e3a\u7a7a\uff0c\u800c\u7528\u4e00\u4e2a\u7f3a\u7701\u503c\u4ee3\u66ff\u7a7a\u503c\uff0c\u5982\u7533\u8bf7\u4e2d\u72b6\u6001\u5b57\u6bb5\u4e0d\u5141\u8bb8\u4e3a\u7a7a\uff0c\u7f3a\u7701\u4e3a\u7533\u8bf7\u3002<\/p>\n

(d) > \u53ca < \u64cd\u4f5c\u7b26\uff08\u5927\u4e8e\u6216\u5c0f\u4e8e\u64cd\u4f5c\u7b26\uff09<\/p>\n

\u5927\u4e8e\u6216\u5c0f\u4e8e\u64cd\u4f5c\u7b26\u4e00\u822c\u60c5\u51b5\u4e0b\u662f\u4e0d\u7528\u8c03\u6574\u7684\uff0c\u56e0\u4e3a\u5b83\u6709\u7d22\u5f15\u5c31\u4f1a\u91c7\u7528\u7d22\u5f15\u67e5\u627e\uff0c\u4f46\u6709\u7684\u60c5\u51b5\u4e0b\u53ef\u4ee5\u5bf9\u5b83\u8fdb\u884c\u4f18\u5316\uff0c\u5982\u4e00\u4e2a\u8868\u6709100\u4e07\u8bb0\u5f55\uff0c\u4e00\u4e2a\u6570\u503c\u578b\u5b57\u6bb5A\uff0c30\u4e07\u8bb0\u5f55\u7684A=0\uff0c30\u4e07\u8bb0\u5f55\u7684A=1\uff0c39\u4e07\u8bb0\u5f55\u7684A=2\uff0c1\u4e07\u8bb0\u5f55\u7684A=3\u3002\u90a3\u4e48\u6267\u884cA>2\u4e0eA>=3\u7684\u6548\u679c\u5c31\u6709\u5f88\u5927\u7684\u533a\u522b\u4e86\uff0c\u56e0\u4e3aA>2\u65f6ORACLE\u4f1a\u5148\u627e\u51fa\u4e3a2\u7684\u8bb0\u5f55\u7d22\u5f15\u518d\u8fdb\u884c\u6bd4\u8f83\uff0c\u800cA>=3\u65f6ORACLE\u5219\u76f4\u63a5\u627e\u5230=3\u7684\u8bb0\u5f55\u7d22\u5f15\u3002<\/p>\n

(e) LIKE\u64cd\u4f5c\u7b26<\/p>\n

LIKE\u64cd\u4f5c\u7b26\u53ef\u4ee5\u5e94\u7528\u901a\u914d\u7b26\u67e5\u8be2\uff0c\u91cc\u9762\u7684\u901a\u914d\u7b26\u7ec4\u5408\u53ef\u80fd\u8fbe\u5230\u51e0\u4e4e\u662f\u4efb\u610f\u7684\u67e5\u8be2\uff0c\u4f46\u662f\u5982\u679c\u7528\u5f97\u4e0d\u597d\u5219\u4f1a\u4ea7\u751f\u6027\u80fd\u4e0a\u7684\u95ee\u9898\uff0c\u5982LIKE \u2018%5400%\u2019 \u8fd9\u79cd\u67e5\u8be2\u4e0d\u4f1a\u5f15\u7528\u7d22\u5f15\uff0c\u800cLIKE \u2018X5400%\u2019\u5219\u4f1a\u5f15\u7528\u8303\u56f4\u7d22\u5f15\u3002<\/p>\n

\u4e00\u4e2a\u5b9e\u9645\u4f8b\u5b50\uff1a\u7528YW_YHJBQK\u8868\u4e2d\u8425\u4e1a\u7f16\u53f7\u540e\u9762\u7684\u6237\u6807\u8bc6\u53f7\u53ef\u6765\u67e5\u8be2\u8425\u4e1a\u7f16\u53f7 YY_BH LIKE \u2018%5400%\u2019 \u8fd9\u4e2a\u6761\u4ef6\u4f1a\u4ea7\u751f\u5168\u8868\u626b\u63cf\uff0c\u5982\u679c\u6539\u6210YY_BH LIKE \u2019X5400%\u2019 OR YY_BH LIKE \u2019B5400%\u2019 \u5219\u4f1a\u5229\u7528YY_BH\u7684\u7d22\u5f15\u8fdb\u884c\u4e24\u4e2a\u8303\u56f4\u7684\u67e5\u8be2\uff0c\u6027\u80fd\u80af\u5b9a\u5927\u5927\u63d0\u9ad8\u3002<\/p>\n

\u5e26\u901a\u914d\u7b26(%)\u7684like\u8bed\u53e5\uff1a<\/p>\n

\u540c\u6837\u4ee5\u4e0a\u9762\u7684\u4f8b\u5b50\u6765\u770b\u8fd9\u79cd\u60c5\u51b5\u3002\u76ee\u524d\u7684\u9700\u6c42\u662f\u8fd9\u6837\u7684\uff0c\u8981\u6c42\u5728\u804c\u5de5\u8868\u4e2d\u67e5\u8be2\u540d\u5b57\u4e2d\u5305\u542bcliton\u7684\u4eba\u3002\u53ef\u4ee5\u91c7\u7528\u5982\u4e0b\u7684\u67e5\u8be2SQL\u8bed\u53e5:<\/p>\n\n\n\n
1<\/td>\nselect * from employee where last_name like ‘%cliton%’;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u8fd9\u91cc\u7531\u4e8e\u901a\u914d\u7b26(%)\u5728\u641c\u5bfb\u8bcd\u9996\u51fa\u73b0\uff0c\u6240\u4ee5Oracle\u7cfb\u7edf\u4e0d\u4f7f\u7528last_name\u7684\u7d22\u5f15\u3002\u5728\u5f88\u591a\u60c5\u51b5\u4e0b\u53ef\u80fd\u65e0\u6cd5\u907f\u514d\u8fd9\u79cd\u60c5\u51b5\uff0c\u4f46\u662f\u4e00\u5b9a\u8981\u5fc3\u4e2d\u6709\u5e95\uff0c\u901a\u914d\u7b26\u5982\u6b64\u4f7f\u7528\u4f1a\u964d\u4f4e\u67e5\u8be2\u901f\u5ea6\u3002\u7136\u800c\u5f53\u901a\u914d\u7b26\u51fa\u73b0\u5728\u5b57\u7b26\u4e32\u5176\u4ed6\u4f4d\u7f6e\u65f6\uff0c\u4f18\u5316\u5668\u5c31\u80fd\u5229\u7528\u7d22\u5f15\u3002\u5728\u4e0b\u9762\u7684\u67e5\u8be2\u4e2d\u7d22\u5f15\u5f97\u5230\u4e86\u4f7f\u7528:<\/p>\n\n\n\n
1<\/td>\nselect * from employee where last_name like ‘c%’;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

(f) UNION\u64cd\u4f5c\u7b26<\/p>\n

UNION\u5728\u8fdb\u884c\u8868\u94fe\u63a5\u540e\u4f1a\u7b5b\u9009\u6389\u91cd\u590d\u7684\u8bb0\u5f55\uff0c\u6240\u4ee5\u5728\u8868\u94fe\u63a5\u540e\u4f1a\u5bf9\u6240\u4ea7\u751f\u7684\u7ed3\u679c\u96c6\u8fdb\u884c\u6392\u5e8f\u8fd0\u7b97\uff0c\u5220\u9664\u91cd\u590d\u7684\u8bb0\u5f55\u518d\u8fd4\u56de\u7ed3\u679c\u3002\u5b9e\u9645\u5927\u90e8\u5206\u5e94\u7528\u4e2d\u662f\u4e0d\u4f1a\u4ea7\u751f\u91cd\u590d\u7684\u8bb0\u5f55\uff0c\u6700\u5e38\u89c1\u7684\u662f\u8fc7\u7a0b\u8868\u4e0e\u5386\u53f2\u8868UNION\u3002\u5982\uff1a<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/td>\n

select * from gc_dfys<\/p>\n

union<\/p>\n

select * from ls_jg_dfys<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u8fd9\u4e2aSQL\u5728\u8fd0\u884c\u65f6\u5148\u53d6\u51fa\u4e24\u4e2a\u8868\u7684\u7ed3\u679c\uff0c\u518d\u7528\u6392\u5e8f\u7a7a\u95f4\u8fdb\u884c\u6392\u5e8f\u5220\u9664\u91cd\u590d\u7684\u8bb0\u5f55\uff0c\u6700\u540e\u8fd4\u56de\u7ed3\u679c\u96c6\uff0c\u5982\u679c\u8868\u6570\u636e\u91cf\u5927\u7684\u8bdd\u53ef\u80fd\u4f1a\u5bfc\u81f4\u7528\u78c1\u76d8\u8fdb\u884c\u6392\u5e8f\u3002<\/p>\n

\u63a8\u8350\u65b9\u6848\uff1a\u91c7\u7528UNION ALL\u64cd\u4f5c\u7b26\u66ff\u4ee3UNION\uff0c\u56e0\u4e3aUNION ALL\u64cd\u4f5c\u53ea\u662f\u7b80\u5355\u7684\u5c06\u4e24\u4e2a\u7ed3\u679c\u5408\u5e76\u540e\u5c31\u8fd4\u56de\u3002<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/td>\n

select * from gc_dfys<\/p>\n

union all<\/p>\n

select * from ls_jg_dfys<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

(g) \u8054\u63a5\u5217<\/p>\n

\u5bf9\u4e8e\u6709\u8054\u63a5\u7684\u5217\uff0c\u5373\u4f7f\u6700\u540e\u7684\u8054\u63a5\u503c\u4e3a\u4e00\u4e2a\u9759\u6001\u503c\uff0c\u4f18\u5316\u5668\u662f\u4e0d\u4f1a\u4f7f\u7528\u7d22\u5f15\u7684\u3002\u6211\u4eec\u4e00\u8d77\u6765\u770b\u4e00\u4e2a\u4f8b\u5b50\uff0c\u5047\u5b9a\u6709\u4e00\u4e2a\u804c\u5de5\u8868(employee)\uff0c\u5bf9\u4e8e\u4e00\u4e2a\u804c\u5de5\u7684\u59d3\u548c\u540d\u5206\u6210\u4e24\u5217\u5b58\u653e(FIRST_NAME\u548cLAST_NAME)\uff0c\u73b0\u5728\u8981\u67e5\u8be2\u4e00\u4e2a\u53eb\u6bd4\u5c14.\u514b\u6797\u987f(Bill Cliton)\u7684\u804c\u5de5\u3002<\/p>\n

\u4e0b\u9762\u662f\u4e00\u4e2a\u91c7\u7528\u8054\u63a5\u67e5\u8be2\u7684SQL\u8bed\u53e5\uff1a<\/p>\n\n\n\n
1<\/td>\nselect * from employss where first_name||”||last_name =’Beill Cliton’;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u4e0a\u9762\u8fd9\u6761\u8bed\u53e5\u5b8c\u5168\u53ef\u4ee5\u67e5\u8be2\u51fa\u662f\u5426\u6709Bill Cliton\u8fd9\u4e2a\u5458\u5de5\uff0c\u4f46\u662f\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\uff0c\u7cfb\u7edf\u4f18\u5316\u5668\u5bf9\u57fa\u4e8elast_name\u521b\u5efa\u7684\u7d22\u5f15\u6ca1\u6709\u4f7f\u7528\u3002\u5f53\u91c7\u7528\u4e0b\u9762\u8fd9\u79cdSQL\u8bed\u53e5\u7684\u7f16\u5199\uff0cOracle\u7cfb\u7edf\u5c31\u53ef\u4ee5\u91c7\u7528\u57fa\u4e8elast_name\u521b\u5efa\u7684\u7d22\u5f15\u3002<\/p>\n\n\n\n
1<\/td>\nwhere first_name =’Beill’ and last_name =’Cliton’;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

(h) Order by\u8bed\u53e5<\/p>\n

ORDER BY\u8bed\u53e5\u51b3\u5b9a\u4e86Oracle\u5982\u4f55\u5c06\u8fd4\u56de\u7684\u67e5\u8be2\u7ed3\u679c\u6392\u5e8f\u3002Order by\u8bed\u53e5\u5bf9\u8981\u6392\u5e8f\u7684\u5217\u6ca1\u6709\u4ec0\u4e48\u7279\u522b\u7684\u9650\u5236\uff0c\u4e5f\u53ef\u4ee5\u5c06\u51fd\u6570\u52a0\u5165\u5217\u4e2d(\u8c61\u8054\u63a5\u6216\u8005\u9644\u52a0\u7b49)\u3002\u4efb\u4f55\u5728Order by\u8bed\u53e5\u7684\u975e\u7d22\u5f15\u9879\u6216\u8005\u6709\u8ba1\u7b97\u8868\u8fbe\u5f0f\u90fd\u5c06\u964d\u4f4e\u67e5\u8be2\u901f\u5ea6\u3002<\/p>\n

\u4ed4\u7ec6\u68c0\u67e5order by\u8bed\u53e5\u4ee5\u627e\u51fa\u975e\u7d22\u5f15\u9879\u6216\u8005\u8868\u8fbe\u5f0f\uff0c\u5b83\u4eec\u4f1a\u964d\u4f4e\u6027\u80fd\u3002\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898\u7684\u529e\u6cd5\u5c31\u662f\u91cd\u5199order by\u8bed\u53e5\u4ee5\u4f7f\u7528\u7d22\u5f15\uff0c\u4e5f\u53ef\u4ee5\u4e3a\u6240\u4f7f\u7528\u7684\u5217\u5efa\u7acb\u53e6\u5916\u4e00\u4e2a\u7d22\u5f15\uff0c\u540c\u65f6\u5e94\u7edd\u5bf9\u907f\u514d\u5728order by\u5b50\u53e5\u4e2d\u4f7f\u7528\u8868\u8fbe\u5f0f\u3002<\/p>\n

(i) NOT<\/p>\n

\u6211\u4eec\u5728\u67e5\u8be2\u65f6\u7ecf\u5e38\u5728where\u5b50\u53e5\u4f7f\u7528\u4e00\u4e9b\u903b\u8f91\u8868\u8fbe\u5f0f\uff0c\u5982\u5927\u4e8e\u3001\u5c0f\u4e8e\u3001\u7b49\u4e8e\u4ee5\u53ca\u4e0d\u7b49\u4e8e\u7b49\u7b49\uff0c\u4e5f\u53ef\u4ee5\u4f7f\u7528and(\u4e0e)\u3001or(\u6216)\u4ee5\u53canot(\u975e)\u3002NOT\u53ef\u7528\u6765\u5bf9\u4efb\u4f55\u903b\u8f91\u8fd0\u7b97\u7b26\u53f7\u53d6\u53cd\u3002\u4e0b\u9762\u662f\u4e00\u4e2aNOT\u5b50\u53e5\u7684\u4f8b\u5b50:<\/p>\n\n\n\n
1<\/td>\nwhere not (status =’VALID’)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u5982\u679c\u8981\u4f7f\u7528NOT\uff0c\u5219\u5e94\u5728\u53d6\u53cd\u7684\u77ed\u8bed\u524d\u9762\u52a0\u4e0a\u62ec\u53f7\uff0c\u5e76\u5728\u77ed\u8bed\u524d\u9762\u52a0\u4e0aNOT\u8fd0\u7b97\u7b26\u3002NOT\u8fd0\u7b97\u7b26\u5305\u542b\u5728\u53e6\u5916\u4e00\u4e2a\u903b\u8f91\u8fd0\u7b97\u7b26\u4e2d\uff0c\u8fd9\u5c31\u662f\u4e0d\u7b49\u4e8e(<>)\u8fd0\u7b97\u7b26\u3002\u6362\u53e5\u8bdd\u8bf4\uff0c\u5373\u4f7f\u4e0d\u5728\u67e5\u8be2where\u5b50\u53e5\u4e2d\u663e\u5f0f\u5730\u52a0\u5165NOT\u8bcd\uff0cNOT\u4ecd\u5728\u8fd0\u7b97\u7b26\u4e2d\uff0c\u89c1\u4e0b\u4f8b:<\/p>\n\n\n\n
1<\/td>\nwhere status <>’INVALID’;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u5bf9\u8fd9\u4e2a\u67e5\u8be2\uff0c\u53ef\u4ee5\u6539\u5199\u4e3a\u4e0d\u4f7f\u7528NOT\uff1a<\/p>\n\n\n\n
1<\/td>\nselect * from employee where salary<3000 or salary>3000;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u867d\u7136\u8fd9\u4e24\u79cd\u67e5\u8be2\u7684\u7ed3\u679c\u4e00\u6837\uff0c\u4f46\u662f\u7b2c\u4e8c\u79cd\u67e5\u8be2\u65b9\u6848\u4f1a\u6bd4\u7b2c\u4e00\u79cd\u67e5\u8be2\u65b9\u6848\u66f4\u5feb\u4e9b\u3002\u7b2c\u4e8c\u79cd\u67e5\u8be2\u5141\u8bb8Oracle\u5bf9salary\u5217\u4f7f\u7528\u7d22\u5f15\uff0c\u800c\u7b2c\u4e00\u79cd\u67e5\u8be2\u5219\u4e0d\u80fd\u4f7f\u7528\u7d22\u5f15\u3002<\/p>\n

2. SQL\u4e66\u5199\u7684\u5f71\u54cd<\/p>\n

(a) \u540c\u4e00\u529f\u80fd\u540c\u4e00\u6027\u80fd\u4e0d\u540c\u5199\u6cd5SQL\u7684\u5f71\u54cd\u3002<\/p>\n

\u5982\u4e00\u4e2aSQL\u5728A\u7a0b\u5e8f\u5458\u5199\u7684\u4e3a\u00a0 Select * from zl_yhjbqk<\/p>\n

B\u7a0b\u5e8f\u5458\u5199\u7684\u4e3a Select * from dlyx.zl_yhjbqk\uff08\u5e26\u8868\u6240\u6709\u8005\u7684\u524d\u7f00\uff09<\/p>\n

C\u7a0b\u5e8f\u5458\u5199\u7684\u4e3a Select * from DLYX.ZLYHJBQK\uff08\u5927\u5199\u8868\u540d\uff09<\/p>\n

D\u7a0b\u5e8f\u5458\u5199\u7684\u4e3a Select *\u00a0 from DLYX.ZLYHJBQK\uff08\u4e2d\u95f4\u591a\u4e86\u7a7a\u683c\uff09<\/p>\n

\u4ee5\u4e0a\u56db\u4e2aSQL\u5728ORACLE\u5206\u6790\u6574\u7406\u4e4b\u540e\u4ea7\u751f\u7684\u7ed3\u679c\u53ca\u6267\u884c\u7684\u65f6\u95f4\u662f\u4e00\u6837\u7684\uff0c\u4f46\u662f\u4eceORACLE\u5171\u4eab\u5185\u5b58SGA\u7684\u539f\u7406\uff0c\u53ef\u4ee5\u5f97\u51faORACLE\u5bf9\u6bcf\u4e2aSQL \u90fd\u4f1a\u5bf9\u5176\u8fdb\u884c\u4e00\u6b21\u5206\u6790\uff0c\u5e76\u4e14\u5360\u7528\u5171\u4eab\u5185\u5b58\uff0c\u5982\u679c\u5c06SQL\u7684\u5b57\u7b26\u4e32\u53ca\u683c\u5f0f\u5199\u5f97\u5b8c\u5168\u76f8\u540c\uff0c\u5219ORACLE\u53ea\u4f1a\u5206\u6790\u4e00\u6b21\uff0c\u5171\u4eab\u5185\u5b58\u4e5f\u53ea\u4f1a\u7559\u4e0b\u4e00\u6b21\u7684\u5206\u6790\u7ed3\u679c\uff0c\u8fd9\u4e0d\u4ec5\u53ef\u4ee5\u51cf\u5c11\u5206\u6790SQL\u7684\u65f6\u95f4\uff0c\u800c\u4e14\u53ef\u4ee5\u51cf\u5c11\u5171\u4eab\u5185\u5b58\u91cd\u590d\u7684\u4fe1\u606f\uff0cORACLE\u4e5f\u53ef\u4ee5\u51c6\u786e\u7edf\u8ba1SQL\u7684\u6267\u884c\u9891\u7387\u3002<\/p>\n

(b) WHERE\u540e\u9762\u7684\u6761\u4ef6\u987a\u5e8f\u5f71\u54cd<\/p>\n

WHERE\u5b50\u53e5\u540e\u9762\u7684\u6761\u4ef6\u987a\u5e8f\u5bf9\u5927\u6570\u636e\u91cf\u8868\u7684\u67e5\u8be2\u4f1a\u4ea7\u751f\u76f4\u63a5\u7684\u5f71\u54cd\u3002\u5982\uff1a<\/p>\n\n\n\n
1<\/p>\n

2<\/td>\n

Select * from zl_yhjbqk where dy_dj = ‘1KV\u4ee5\u4e0b’ and xh_bz=1<\/p>\n

Select * from zl_yhjbqk where xh_bz=1 and dy_dj = ‘1KV\u4ee5\u4e0b’<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u4ee5\u4e0a\u4e24\u4e2aSQL\u4e2ddy_dj\uff08\u7535\u538b\u7b49\u7ea7\uff09\u53caxh_bz\uff08\u9500\u6237\u6807\u5fd7\uff09\u4e24\u4e2a\u5b57\u6bb5\u90fd\u6ca1\u8fdb\u884c\u7d22\u5f15\uff0c\u6240\u4ee5\u6267\u884c\u7684\u65f6\u5019\u90fd\u662f\u5168\u8868\u626b\u63cf\uff0c\u7b2c\u4e00\u6761SQL\u7684dy_dj = \u20191KV\u4ee5\u4e0b\u2019\u6761\u4ef6\u5728\u8bb0\u5f55\u96c6\u5185\u6bd4\u7387\u4e3a99%\uff0c\u800cxh_bz=1\u7684\u6bd4\u7387\u53ea\u4e3a0.5%\uff0c\u5728\u8fdb\u884c\u7b2c\u4e00\u6761SQL\u7684\u65f6\u501999%\u6761\u8bb0\u5f55\u90fd\u8fdb\u884cdy_dj\u53caxh_bz\u7684\u6bd4\u8f83\uff0c\u800c\u5728\u8fdb\u884c\u7b2c\u4e8c\u6761SQL\u7684\u65f6\u50190.5%\u6761\u8bb0\u5f55\u90fd\u8fdb\u884cdy_dj\u53caxh_bz\u7684\u6bd4\u8f83\uff0c\u4ee5\u6b64\u53ef\u4ee5\u5f97\u51fa\u7b2c\u4e8c\u6761SQL\u7684CPU\u5360\u7528\u7387\u660e\u663e\u6bd4\u7b2c\u4e00\u6761\u4f4e\u3002<\/p>\n

(c) \u67e5\u8be2\u8868\u987a\u5e8f\u7684\u5f71\u54cd<\/p>\n

\u5728FROM\u540e\u9762\u7684\u8868\u4e2d\u7684\u5217\u8868\u987a\u5e8f\u4f1a\u5bf9SQL\u6267\u884c\u6027\u80fd\u5f71\u54cd\uff0c\u5728\u6ca1\u6709\u7d22\u5f15\u53caORACLE\u6ca1\u6709\u5bf9\u8868\u8fdb\u884c\u7edf\u8ba1\u5206\u6790\u7684\u60c5\u51b5\u4e0b\uff0cORACLE\u4f1a\u6309\u8868\u51fa\u73b0\u7684\u987a\u5e8f\u8fdb\u884c\u94fe\u63a5\uff0c\u7531\u6b64\u53ef\u89c1\u8868\u7684\u987a\u5e8f\u4e0d\u5bf9\u65f6\u4f1a\u4ea7\u751f\u5341\u5206\u8017\u670d\u7269\u5668\u8d44\u6e90\u7684\u6570\u636e\u4ea4\u53c9\u3002\uff08\u6ce8\uff1a\u5982\u679c\u5bf9\u8868\u8fdb\u884c\u4e86\u7edf\u8ba1\u5206\u6790\uff0cORACLE\u4f1a\u81ea\u52a8\u5148\u8fdb\u5c0f\u8868\u7684\u94fe\u63a5\uff0c\u518d\u8fdb\u884c\u5927\u8868\u7684\u94fe\u63a5\uff09<\/p>\n

3. SQL\u8bed\u53e5\u7d22\u5f15\u7684\u5229\u7528<\/p>\n

(a) \u5bf9\u6761\u4ef6\u5b57\u6bb5\u7684\u4e00\u4e9b\u4f18\u5316<\/p>\n

\u91c7\u7528\u51fd\u6570\u5904\u7406\u7684\u5b57\u6bb5\u4e0d\u80fd\u5229\u7528\u7d22\u5f15\uff0c\u5982\uff1a<\/p>\n\n\n\n
1<\/p>\n

2<\/td>\n

substr(hbs_bh,1,4)=\u20195400\u2019\uff0c\u4f18\u5316\u5904\u7406\uff1ahbs_bh like \u20185400%\u2019<\/p>\n

trunc(sk_rq)=trunc(sysdate)\uff0c \u4f18\u5316\u5904\u7406\uff1ask_rq>=trunc(sysdate) and sk_rq<trunc(sysdate+1)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u8fdb\u884c\u4e86\u663e\u5f0f\u6216\u9690\u5f0f\u7684\u8fd0\u7b97\u7684\u5b57\u6bb5\u4e0d\u80fd\u8fdb\u884c\u7d22\u5f15\uff0c\u5982\uff1ass_df+20>50\uff0c\u4f18\u5316\u5904\u7406\uff1ass_df>30<\/p>\n\n\n\n
1<\/p>\n

2<\/td>\n

\u2018X\u2019 || hbs_bh>\u2019X5400021452\u2019\uff0c\u4f18\u5316\u5904\u7406\uff1ahbs_bh>\u20195400021542\u2019<\/p>\n

sk_rq+5=sysdate\uff0c\u4f18\u5316\u5904\u7406\uff1ask_rq=sysdate-5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

hbs_bh=5401002554\uff0c\u4f18\u5316\u5904\u7406\uff1ahbs_bh=\u2019 5401002554\u2019\uff0c\u6ce8\uff1a\u6b64\u6761\u4ef6\u5bf9hbs_bh \u8fdb\u884c\u9690\u5f0f\u7684to_number\u8f6c\u6362\uff0c\u56e0\u4e3ahbs_bh\u5b57\u6bb5\u662f\u5b57\u7b26\u578b\u3002<\/p>\n

\u6761\u4ef6\u5185\u5305\u62ec\u4e86\u591a\u4e2a\u672c\u8868\u7684\u5b57\u6bb5\u8fd0\u7b97\u65f6\u4e0d\u80fd\u8fdb\u884c\u7d22\u5f15\uff0c\u5982\uff1a<\/p>\n\n\n\n
1<\/p>\n

2<\/td>\n

ys_df>cx_df\uff0c\u65e0\u6cd5\u8fdb\u884c\u4f18\u5316<\/p>\n

qc_bh || kh_bh=\u20195400250000\u2019\uff0c\u4f18\u5316\u5904\u7406\uff1aqc_bh=\u20195400\u2019 and kh_bh=\u2019250000\u2019<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

4. \u66f4\u591a\u65b9\u9762SQL\u4f18\u5316\u8d44\u6599\u5206\u4eab<\/p>\n

\uff081\uff09 \u9009\u62e9\u6700\u6709\u6548\u7387\u7684\u8868\u540d\u987a\u5e8f(\u53ea\u5728\u57fa\u4e8e\u89c4\u5219\u7684\u4f18\u5316\u5668\u4e2d\u6709\u6548)\uff1a<\/p>\n

ORACLE \u7684\u89e3\u6790\u5668\u6309\u7167\u4ece\u53f3\u5230\u5de6\u7684\u987a\u5e8f\u5904\u7406FROM\u5b50\u53e5\u4e2d\u7684\u8868\u540d\uff0cFROM\u5b50\u53e5\u4e2d\u5199\u5728\u6700\u540e\u7684\u8868(\u57fa\u7840\u8868 driving table)\u5c06\u88ab\u6700\u5148\u5904\u7406\uff0c\u5728FROM\u5b50\u53e5\u4e2d\u5305\u542b\u591a\u4e2a\u8868\u7684\u60c5\u51b5\u4e0b,\u4f60\u5fc5\u987b\u9009\u62e9\u8bb0\u5f55\u6761\u6570\u6700\u5c11\u7684\u8868\u4f5c\u4e3a\u57fa\u7840\u8868\u3002\u5982\u679c\u67093\u4e2a\u4ee5\u4e0a\u7684\u8868\u8fde\u63a5\u67e5\u8be2, \u90a3\u5c31\u9700\u8981\u9009\u62e9\u4ea4\u53c9\u8868(intersection table)\u4f5c\u4e3a\u57fa\u7840\u8868, \u4ea4\u53c9\u8868\u662f\u6307\u90a3\u4e2a\u88ab\u5176\u4ed6\u8868\u6240\u5f15\u7528\u7684\u8868.<\/p>\n

\uff082\uff09 WHERE\u5b50\u53e5\u4e2d\u7684\u8fde\u63a5\u987a\u5e8f\uff1a<\/p>\n

ORACLE\u91c7\u7528\u81ea\u4e0b\u800c\u4e0a\u7684\u987a\u5e8f\u89e3\u6790WHERE\u5b50\u53e5,\u6839\u636e\u8fd9\u4e2a\u539f\u7406,\u8868\u4e4b\u95f4\u7684\u8fde\u63a5\u5fc5\u987b\u5199\u5728\u5176\u4ed6WHERE\u6761\u4ef6\u4e4b\u524d, \u90a3\u4e9b\u53ef\u4ee5\u8fc7\u6ee4\u6389\u6700\u5927\u6570\u91cf\u8bb0\u5f55\u7684\u6761\u4ef6\u5fc5\u987b\u5199\u5728WHERE\u5b50\u53e5\u7684\u672b\u5c3e.<\/p>\n

\uff083\uff09 SELECT\u5b50\u53e5\u4e2d\u907f\u514d\u4f7f\u7528 \u2018 * \u2018\uff1a<\/p>\n

ORACLE\u5728\u89e3\u6790\u7684\u8fc7\u7a0b\u4e2d, \u4f1a\u5c06\u2019*\u2019 \u4f9d\u6b21\u8f6c\u6362\u6210\u6240\u6709\u7684\u5217\u540d, \u8fd9\u4e2a\u5de5\u4f5c\u662f\u901a\u8fc7\u67e5\u8be2\u6570\u636e\u5b57\u5178\u5b8c\u6210\u7684, \u8fd9\u610f\u5473\u7740\u5c06\u8017\u8d39\u66f4\u591a\u7684\u65f6\u95f4\u3002<\/p>\n

\uff084\uff09 \u51cf\u5c11\u8bbf\u95ee\u6570\u636e\u5e93\u7684\u6b21\u6570\uff1a<\/p>\n

ORACLE\u5728\u5185\u90e8\u6267\u884c\u4e86\u8bb8\u591a\u5de5\u4f5c: \u89e3\u6790SQL\u8bed\u53e5, \u4f30\u7b97\u7d22\u5f15\u7684\u5229\u7528\u7387, \u7ed1\u5b9a\u53d8\u91cf , \u8bfb\u6570\u636e\u5757\u7b49\u3002<\/p>\n

\uff085\uff09 \u5728SQL*Plus , SQL*Forms\u548cPro*C\u4e2d\u91cd\u65b0\u8bbe\u7f6eARRAYSIZE\u53c2\u6570, \u53ef\u4ee5\u589e\u52a0\u6bcf\u6b21\u6570\u636e\u5e93\u8bbf\u95ee\u7684\u68c0\u7d22\u6570\u636e\u91cf ,\u5efa\u8bae\u503c\u4e3a200\u3002<\/p>\n

\uff086\uff09 \u4f7f\u7528DECODE\u51fd\u6570\u6765\u51cf\u5c11\u5904\u7406\u65f6\u95f4\uff1a<\/p>\n

\u4f7f\u7528DECODE\u51fd\u6570\u53ef\u4ee5\u907f\u514d\u91cd\u590d\u626b\u63cf\u76f8\u540c\u8bb0\u5f55\u6216\u91cd\u590d\u8fde\u63a5\u76f8\u540c\u7684\u8868.<\/p>\n

\uff087\uff09 \u6574\u5408\u7b80\u5355,\u65e0\u5173\u8054\u7684\u6570\u636e\u5e93\u8bbf\u95ee\uff1a<\/p>\n

\u5982\u679c\u4f60\u6709\u51e0\u4e2a\u7b80\u5355\u7684\u6570\u636e\u5e93\u67e5\u8be2\u8bed\u53e5,\u4f60\u53ef\u4ee5\u628a\u5b83\u4eec\u6574\u5408\u5230\u4e00\u4e2a\u67e5\u8be2\u4e2d(\u5373\u4f7f\u5b83\u4eec\u4e4b\u95f4\u6ca1\u6709\u5173\u7cfb) \u3002<\/p>\n

\uff088\uff09 \u5220\u9664\u91cd\u590d\u8bb0\u5f55\uff1a<\/p>\n

\u6700\u9ad8\u6548\u7684\u5220\u9664\u91cd\u590d\u8bb0\u5f55\u65b9\u6cd5 ( \u56e0\u4e3a\u4f7f\u7528\u4e86ROWID)\u4f8b\u5b50\uff1a<\/p>\n\n\n\n
1<\/td>\nDELETE\u00a0 FROM\u00a0 EMP E\u00a0 WHERE\u00a0 E.ROWID > (SELECT MIN(X.ROWID) FROM\u00a0 EMP X\u00a0 WHERE\u00a0 X.EMP_NO = E.EMP_NO)\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff089\uff09 \u7528TRUNCATE\u66ff\u4ee3DELETE\uff1a<\/p>\n

\u5f53\u5220\u9664\u8868\u4e2d\u7684\u8bb0\u5f55\u65f6,\u5728\u901a\u5e38\u60c5\u51b5\u4e0b, \u56de\u6eda\u6bb5(rollback segments ) \u7528\u6765\u5b58\u653e\u53ef\u4ee5\u88ab\u6062\u590d\u7684\u4fe1\u606f. \u5982\u679c\u4f60\u6ca1\u6709COMMIT\u4e8b\u52a1,ORACLE\u4f1a\u5c06\u6570\u636e\u6062\u590d\u5230\u5220\u9664\u4e4b\u524d\u7684\u72b6\u6001(\u51c6\u786e\u5730\u8bf4\u662f\u6062\u590d\u5230\u6267\u884c\u5220\u9664\u547d\u4ee4\u4e4b\u524d\u7684\u72b6\u51b5) \u800c\u5f53\u8fd0\u7528TRUNCATE\u65f6, \u56de\u6eda\u6bb5\u4e0d\u518d\u5b58\u653e\u4efb\u4f55\u53ef\u88ab\u6062\u590d\u7684\u4fe1\u606f.\u5f53\u547d\u4ee4\u8fd0\u884c\u540e,\u6570\u636e\u4e0d\u80fd\u88ab\u6062\u590d.\u56e0\u6b64\u5f88\u5c11\u7684\u8d44\u6e90\u88ab\u8c03\u7528,\u6267\u884c\u65f6\u95f4\u4e5f\u4f1a\u5f88\u77ed. (\u8bd1\u8005\u6309: TRUNCATE\u53ea\u5728\u5220\u9664\u5168\u8868\u9002\u7528,TRUNCATE\u662fDDL\u4e0d\u662fDML) \u3002<\/p>\n

\uff0810\uff09 \u5c3d\u91cf\u591a\u4f7f\u7528COMMIT\uff1a<\/p>\n

\u53ea\u8981\u6709\u53ef\u80fd,\u5728\u7a0b\u5e8f\u4e2d\u5c3d\u91cf\u591a\u4f7f\u7528COMMIT, \u8fd9\u6837\u7a0b\u5e8f\u7684\u6027\u80fd\u5f97\u5230\u63d0\u9ad8,\u9700\u6c42\u4e5f\u4f1a\u56e0\u4e3aCOMMIT\u6240\u91ca\u653e\u7684\u8d44\u6e90\u800c\u51cf\u5c11\uff0cCOMMIT\u6240\u91ca\u653e\u7684\u8d44\u6e90:<\/p>\n

a. \u56de\u6eda\u6bb5\u4e0a\u7528\u4e8e\u6062\u590d\u6570\u636e\u7684\u4fe1\u606f.<\/p>\n

b. \u88ab\u7a0b\u5e8f\u8bed\u53e5\u83b7\u5f97\u7684\u9501<\/p>\n

c. redo log buffer \u4e2d\u7684\u7a7a\u95f4<\/p>\n

d. ORACLE\u4e3a\u7ba1\u7406\u4e0a\u8ff03\u79cd\u8d44\u6e90\u4e2d\u7684\u5185\u90e8\u82b1\u8d39<\/p>\n

\uff0811\uff09 \u7528Where\u5b50\u53e5\u66ff\u6362HAVING\u5b50\u53e5\uff1a<\/p>\n

\u907f\u514d\u4f7f\u7528HAVING\u5b50\u53e5, HAVING \u53ea\u4f1a\u5728\u68c0\u7d22\u51fa\u6240\u6709\u8bb0\u5f55\u4e4b\u540e\u624d\u5bf9\u7ed3\u679c\u96c6\u8fdb\u884c\u8fc7\u6ee4. \u8fd9\u4e2a\u5904\u7406\u9700\u8981\u6392\u5e8f,\u603b\u8ba1\u7b49\u64cd\u4f5c. \u5982\u679c\u80fd\u901a\u8fc7WHERE\u5b50\u53e5\u9650\u5236\u8bb0\u5f55\u7684\u6570\u76ee,\u90a3\u5c31\u80fd\u51cf\u5c11\u8fd9\u65b9\u9762\u7684\u5f00\u9500. (\u975eoracle\u4e2d)on\u3001where\u3001having\u8fd9\u4e09\u4e2a\u90fd\u53ef\u4ee5\u52a0\u6761\u4ef6\u7684\u5b50\u53e5\u4e2d\uff0con\u662f\u6700\u5148\u6267\u884c\uff0cwhere\u6b21\u4e4b\uff0chaving\u6700\u540e\uff0c\u56e0\u4e3aon\u662f\u5148\u628a\u4e0d\u7b26\u5408\u6761\u4ef6\u7684\u8bb0\u5f55\u8fc7\u6ee4\u540e\u624d\u8fdb\u884c\u7edf\u8ba1\uff0c\u5b83\u5c31\u53ef\u4ee5\u51cf\u5c11\u4e2d\u95f4\u8fd0\u7b97\u8981\u5904\u7406\u7684\u6570\u636e\uff0c\u6309\u7406\u8bf4\u5e94\u8be5\u901f\u5ea6\u662f\u6700\u5feb\u7684\uff0cwhere\u4e5f\u5e94\u8be5\u6bd4having\u5feb\u70b9\u7684\uff0c\u56e0\u4e3a\u5b83\u8fc7\u6ee4\u6570\u636e\u540e\u624d\u8fdb\u884csum\uff0c\u5728\u4e24\u4e2a\u8868\u8054\u63a5\u65f6\u624d\u7528on\u7684\uff0c\u6240\u4ee5\u5728\u4e00\u4e2a\u8868\u7684\u65f6\u5019\uff0c\u5c31\u5269\u4e0bwhere\u8ddfhaving\u6bd4\u8f83\u4e86\u3002\u5728\u8fd9\u5355\u8868\u67e5\u8be2\u7edf\u8ba1\u7684\u60c5\u51b5\u4e0b\uff0c\u5982\u679c\u8981\u8fc7\u6ee4\u7684\u6761\u4ef6\u6ca1\u6709\u6d89\u53ca\u5230\u8981\u8ba1\u7b97\u5b57\u6bb5\uff0c\u90a3\u5b83\u4eec\u7684\u7ed3\u679c\u662f\u4e00\u6837\u7684\uff0c\u53ea\u662fwhere\u53ef\u4ee5\u4f7f\u7528rushmore\u6280\u672f\uff0c\u800chaving\u5c31\u4e0d\u80fd\uff0c\u5728\u901f\u5ea6\u4e0a\u540e\u8005\u8981\u6162\u5982\u679c\u8981\u6d89\u53ca\u5230\u8ba1\u7b97\u7684\u5b57 \u6bb5\uff0c\u5c31\u8868\u793a\u5728\u6ca1\u8ba1\u7b97\u4e4b\u524d\uff0c\u8fd9\u4e2a\u5b57\u6bb5\u7684\u503c\u662f\u4e0d\u786e\u5b9a\u7684\uff0c\u6839\u636e\u4e0a\u7bc7\u5199\u7684\u5de5\u4f5c\u6d41\u7a0b\uff0cwhere\u7684\u4f5c\u7528\u65f6\u95f4\u662f\u5728\u8ba1\u7b97\u4e4b\u524d\u5c31\u5b8c\u6210\u7684\uff0c\u800chaving\u5c31\u662f\u5728\u8ba1\u7b97\u540e\u624d\u8d77\u4f5c \u7528\u7684\uff0c\u6240\u4ee5\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4e24\u8005\u7684\u7ed3\u679c\u4f1a\u4e0d\u540c\u3002\u5728\u591a\u8868\u8054\u63a5\u67e5\u8be2\u65f6\uff0con\u6bd4where\u66f4\u65e9\u8d77\u4f5c\u7528\u3002\u7cfb\u7edf\u9996\u5148\u6839\u636e\u5404\u4e2a\u8868\u4e4b\u95f4\u7684\u8054\u63a5\u6761\u4ef6\uff0c\u628a\u591a\u4e2a\u8868\u5408\u6210\u4e00\u4e2a\u4e34\u65f6\u8868 \u540e\uff0c\u518d\u7531where\u8fdb\u884c\u8fc7\u6ee4\uff0c\u7136\u540e\u518d\u8ba1\u7b97\uff0c\u8ba1\u7b97\u5b8c\u540e\u518d\u7531having\u8fdb\u884c\u8fc7\u6ee4\u3002\u7531\u6b64\u53ef\u89c1\uff0c\u8981\u60f3\u8fc7\u6ee4\u6761\u4ef6\u8d77\u5230\u6b63\u786e\u7684\u4f5c\u7528\uff0c\u9996\u5148\u8981\u660e\u767d\u8fd9\u4e2a\u6761\u4ef6\u5e94\u8be5\u5728\u4ec0\u4e48\u65f6\u5019\u8d77\u4f5c\u7528\uff0c\u7136\u540e\u518d\u51b3\u5b9a\u653e\u5728\u90a3\u91cc\u3002<\/p>\n

\uff0812\uff09 \u51cf\u5c11\u5bf9\u8868\u7684\u67e5\u8be2\uff1a<\/p>\n

\u5728\u542b\u6709\u5b50\u67e5\u8be2\u7684SQL\u8bed\u53e5\u4e2d,\u8981\u7279\u522b\u6ce8\u610f\u51cf\u5c11\u5bf9\u8868\u7684\u67e5\u8be2.\u4f8b\u5b50\uff1a<\/p>\n\n\n\n
1<\/td>\nSELECT\u00a0 TAB_NAME FROM TABLES WHERE (TAB_NAME,DB_VER) = ( SELECT TAB_NAME,DB_VER FROM\u00a0 TAB_COLUMNS\u00a0 WHERE\u00a0 VERSION = 604)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0813\uff09 \u901a\u8fc7\u5185\u90e8\u51fd\u6570\u63d0\u9ad8SQL\u6548\u7387\uff1a<\/p>\n

\u590d\u6742\u7684SQL\u5f80\u5f80\u727a\u7272\u4e86\u6267\u884c\u6548\u7387. \u80fd\u591f\u638c\u63e1\u4e0a\u9762\u7684\u8fd0\u7528\u51fd\u6570\u89e3\u51b3\u95ee\u9898\u7684\u65b9\u6cd5\u5728\u5b9e\u9645\u5de5\u4f5c\u4e2d\u662f\u975e\u5e38\u6709\u610f\u4e49\u7684\u3002<\/p>\n

\uff0814\uff09 \u4f7f\u7528\u8868\u7684\u522b\u540d(Alias)\uff1a<\/p>\n

\u5f53\u5728SQL\u8bed\u53e5\u4e2d\u8fde\u63a5\u591a\u4e2a\u8868\u65f6, \u8bf7\u4f7f\u7528\u8868\u7684\u522b\u540d\u5e76\u628a\u522b\u540d\u524d\u7f00\u4e8e\u6bcf\u4e2aColumn\u4e0a.\u8fd9\u6837\u4e00\u6765,\u5c31\u53ef\u4ee5\u51cf\u5c11\u89e3\u6790\u7684\u65f6\u95f4\u5e76\u51cf\u5c11\u90a3\u4e9b\u7531Column\u6b67\u4e49\u5f15\u8d77\u7684\u8bed\u6cd5\u9519\u8bef\u3002<\/p>\n

\uff0815\uff09 \u7528EXISTS\u66ff\u4ee3IN\u3001\u7528NOT EXISTS\u66ff\u4ee3NOT IN\uff1a<\/p>\n

\u5728\u8bb8\u591a\u57fa\u4e8e\u57fa\u7840\u8868\u7684\u67e5\u8be2\u4e2d,\u4e3a\u4e86\u6ee1\u8db3\u4e00\u4e2a\u6761\u4ef6,\u5f80\u5f80\u9700\u8981\u5bf9\u53e6\u4e00\u4e2a\u8868\u8fdb\u884c\u8054\u63a5.\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b, \u4f7f\u7528EXISTS(\u6216NOT EXISTS)\u901a\u5e38\u5c06\u63d0\u9ad8\u67e5\u8be2\u7684\u6548\u7387. \u5728\u5b50\u67e5\u8be2\u4e2d,NOT IN\u5b50\u53e5\u5c06\u6267\u884c\u4e00\u4e2a\u5185\u90e8\u7684\u6392\u5e8f\u548c\u5408\u5e76. \u65e0\u8bba\u5728\u54ea\u79cd\u60c5\u51b5\u4e0b,NOT IN\u90fd\u662f\u6700\u4f4e\u6548\u7684 (\u56e0\u4e3a\u5b83\u5bf9\u5b50\u67e5\u8be2\u4e2d\u7684\u8868\u6267\u884c\u4e86\u4e00\u4e2a\u5168\u8868\u904d\u5386). \u4e3a\u4e86\u907f\u514d\u4f7f\u7528NOT IN ,\u6211\u4eec\u53ef\u4ee5\u628a\u5b83\u6539\u5199\u6210\u5916\u8fde\u63a5(Outer Joins)\u6216NOT EXISTS\u3002<\/p>\n

\u4f8b\u5b50\uff1a<\/p>\n\n\n\n
1<\/p>\n

2<\/td>\n

\uff08\u9ad8\u6548\uff09SELECT * FROM\u00a0 EMP (\u57fa\u7840\u8868)\u00a0 WHERE\u00a0 EMPNO > 0\u00a0 AND\u00a0 EXISTS (SELECT \u2018X’\u00a0 FROM DEPT\u00a0 WHERE\u00a0 DEPT.DEPTNO = EMP.DEPTNO\u00a0 AND\u00a0 LOC = \u2018MELB’)<\/p>\n

(\u4f4e\u6548)SELECT\u00a0 * FROM\u00a0 EMP (\u57fa\u7840\u8868)\u00a0 WHERE\u00a0 EMPNO > 0\u00a0 AND\u00a0 DEPTNO IN(SELECT DEPTNO\u00a0 FROM\u00a0 DEPT\u00a0 WHERE\u00a0 LOC = \u2018MELB’)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0816\uff09 \u8bc6\u522b\u2019\u4f4e\u6548\u6267\u884c\u2019\u7684SQL\u8bed\u53e5\uff1a<\/p>\n

\u867d\u7136\u76ee\u524d\u5404\u79cd\u5173\u4e8eSQL\u4f18\u5316\u7684\u56fe\u5f62\u5316\u5de5\u5177\u5c42\u51fa\u4e0d\u7a77,\u4f46\u662f\u5199\u51fa\u81ea\u5df1\u7684SQL\u5de5\u5177\u6765\u89e3\u51b3\u95ee\u9898\u59cb\u7ec8\u662f\u4e00\u4e2a\u6700\u597d\u7684\u65b9\u6cd5\uff1a<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/p>\n

5<\/p>\n

6<\/p>\n

7<\/p>\n

8<\/p>\n

9<\/td>\n

SELECT\u00a0 EXECUTIONS , DISK_READS, BUFFER_GETS,<\/p>\n

ROUND((BUFFER_GETS-DISK_READS)\/BUFFER_GETS,2) Hit_radio,<\/p>\n

ROUND(DISK_READS\/EXECUTIONS,2) Reads_per_run,<\/p>\n

SQL_TEXT<\/p>\n

FROM\u00a0 V$SQLAREA<\/p>\n

WHERE\u00a0 EXECUTIONS>0<\/p>\n

AND\u00a0 BUFFER_GETS > 0<\/p>\n

AND\u00a0 (BUFFER_GETS-DISK_READS)\/BUFFER_GETS < 0.8<\/p>\n

ORDER BY\u00a0 4 DESC;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0817\uff09 \u7528\u7d22\u5f15\u63d0\u9ad8\u6548\u7387\uff1a<\/p>\n

\u7d22\u5f15\u662f\u8868\u7684\u4e00\u4e2a\u6982\u5ff5\u90e8\u5206,\u7528\u6765\u63d0\u9ad8\u68c0\u7d22\u6570\u636e\u7684\u6548\u7387\uff0cORACLE\u4f7f\u7528\u4e86\u4e00\u4e2a\u590d\u6742\u7684\u81ea\u5e73\u8861B-tree\u7ed3\u6784. \u901a\u5e38,\u901a\u8fc7\u7d22\u5f15\u67e5\u8be2\u6570\u636e\u6bd4\u5168\u8868\u626b\u63cf\u8981\u5feb. \u5f53ORACLE\u627e\u51fa\u6267\u884c\u67e5\u8be2\u548cUpdate\u8bed\u53e5\u7684\u6700\u4f73\u8def\u5f84\u65f6, ORACLE\u4f18\u5316\u5668\u5c06\u4f7f\u7528\u7d22\u5f15. \u540c\u6837\u5728\u8054\u7ed3\u591a\u4e2a\u8868\u65f6\u4f7f\u7528\u7d22\u5f15\u4e5f\u53ef\u4ee5\u63d0\u9ad8\u6548\u7387. \u53e6\u4e00\u4e2a\u4f7f\u7528\u7d22\u5f15\u7684\u597d\u5904\u662f,\u5b83\u63d0\u4f9b\u4e86\u4e3b\u952e(primary key)\u7684\u552f\u4e00\u6027\u9a8c\u8bc1.\u3002\u90a3\u4e9bLONG\u6216LONG RAW\u6570\u636e\u7c7b\u578b, \u4f60\u53ef\u4ee5\u7d22\u5f15\u51e0\u4e4e\u6240\u6709\u7684\u5217. \u901a\u5e38, \u5728\u5927\u578b\u8868\u4e2d\u4f7f\u7528\u7d22\u5f15\u7279\u522b\u6709\u6548. \u5f53\u7136,\u4f60\u4e5f\u4f1a\u53d1\u73b0, \u5728\u626b\u63cf\u5c0f\u8868\u65f6,\u4f7f\u7528\u7d22\u5f15\u540c\u6837\u80fd\u63d0\u9ad8\u6548\u7387. \u867d\u7136\u4f7f\u7528\u7d22\u5f15\u80fd\u5f97\u5230\u67e5\u8be2\u6548\u7387\u7684\u63d0\u9ad8,\u4f46\u662f\u6211\u4eec\u4e5f\u5fc5\u987b\u6ce8\u610f\u5230\u5b83\u7684\u4ee3\u4ef7. \u7d22\u5f15\u9700\u8981\u7a7a\u95f4\u6765\u5b58\u50a8,\u4e5f\u9700\u8981\u5b9a\u671f\u7ef4\u62a4, \u6bcf\u5f53\u6709\u8bb0\u5f55\u5728\u8868\u4e2d\u589e\u51cf\u6216\u7d22\u5f15\u5217\u88ab\u4fee\u6539\u65f6, \u7d22\u5f15\u672c\u8eab\u4e5f\u4f1a\u88ab\u4fee\u6539. \u8fd9\u610f\u5473\u7740\u6bcf\u6761\u8bb0\u5f55\u7684INSERT , DELETE , UPDATE\u5c06\u4e3a\u6b64\u591a\u4ed8\u51fa4 , 5 \u6b21\u7684\u78c1\u76d8I\/O . \u56e0\u4e3a\u7d22\u5f15\u9700\u8981\u989d\u5916\u7684\u5b58\u50a8\u7a7a\u95f4\u548c\u5904\u7406,\u90a3\u4e9b\u4e0d\u5fc5\u8981\u7684\u7d22\u5f15\u53cd\u800c\u4f1a\u4f7f\u67e5\u8be2\u53cd\u5e94\u65f6\u95f4\u53d8\u6162.\u3002\u5b9a\u671f\u7684\u91cd\u6784\u7d22\u5f15\u662f\u6709\u5fc5\u8981\u7684\uff1a<\/p>\n\n\n\n
1<\/td>\nALTER\u00a0 INDEX <INDEXNAME> REBUILD <TABLESPACENAME><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0818\uff09 \u7528EXISTS\u66ff\u6362DISTINCT\uff1a<\/p>\n

\u5f53\u63d0\u4ea4\u4e00\u4e2a\u5305\u542b\u4e00\u5bf9\u591a\u8868\u4fe1\u606f(\u6bd4\u5982\u90e8\u95e8\u8868\u548c\u96c7\u5458\u8868)\u7684\u67e5\u8be2\u65f6,\u907f\u514d\u5728SELECT\u5b50\u53e5\u4e2d\u4f7f\u7528DISTINCT. \u4e00\u822c\u53ef\u4ee5\u8003\u8651\u7528EXIST\u66ff\u6362, EXISTS \u4f7f\u67e5\u8be2\u66f4\u4e3a\u8fc5\u901f,\u56e0\u4e3aRDBMS\u6838\u5fc3\u6a21\u5757\u5c06\u5728\u5b50\u67e5\u8be2\u7684\u6761\u4ef6\u4e00\u65e6\u6ee1\u8db3\u540e,\u7acb\u523b\u8fd4\u56de\u7ed3\u679c. \u4f8b\u5b50\uff1a<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/td>\n

(\u4f4e\u6548):<\/p>\n

SELECT\u00a0 DISTINCT\u00a0 DEPT_NO,DEPT_NAME\u00a0 FROM\u00a0 DEPT D , EMP E WHERE\u00a0 D.DEPT_NO = E.DEPT_NO<\/p>\n

(\u9ad8\u6548):<\/p>\n

SELECT\u00a0 DEPT_NO,DEPT_NAME\u00a0 FROM\u00a0 DEPT D\u00a0 WHERE\u00a0 EXISTS ( SELECT \u2018X’\u00a0 FROM\u00a0 EMP E\u00a0 WHERE E.DEPT_NO = D.DEPT_NO);<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0819\uff09 sql\u8bed\u53e5\u7528\u5927\u5199\u7684\uff1b\u56e0\u4e3aoracle\u603b\u662f\u5148\u89e3\u6790sql\u8bed\u53e5\uff0c\u628a\u5c0f\u5199\u7684\u5b57\u6bcd\u8f6c\u6362\u6210\u5927\u5199\u7684\u518d\u6267\u884c\u3002<\/p>\n

\uff0820\uff09 \u5728java\u4ee3\u7801\u4e2d\u5c3d\u91cf\u5c11\u7528\u8fde\u63a5\u7b26\u201c\uff0b\u201d\u8fde\u63a5\u5b57\u7b26\u4e32\uff01<\/p>\n

\uff0821\uff09 \u907f\u514d\u5728\u7d22\u5f15\u5217\u4e0a\u4f7f\u7528NOT\uff0c\u901a\u5e38\u6211\u4eec\u8981\u907f\u514d\u5728\u7d22\u5f15\u5217\u4e0a\u4f7f\u7528NOT, NOT\u4f1a\u4ea7\u751f\u5728\u548c\u5728\u7d22\u5f15\u5217\u4e0a\u4f7f\u7528\u51fd\u6570\u76f8\u540c\u7684\u5f71\u54cd. \u5f53ORACLE\u201d\u9047\u5230\u201dNOT,\u4ed6\u5c31\u4f1a\u505c\u6b62\u4f7f\u7528\u7d22\u5f15\u8f6c\u800c\u6267\u884c\u5168\u8868\u626b\u63cf\u3002<\/p>\n

\uff0822\uff09 \u907f\u514d\u5728\u7d22\u5f15\u5217\u4e0a\u4f7f\u7528\u8ba1\u7b97<\/p>\n

WHERE\u5b50\u53e5\u4e2d\uff0c\u5982\u679c\u7d22\u5f15\u5217\u662f\u51fd\u6570\u7684\u4e00\u90e8\u5206\uff0e\u4f18\u5316\u5668\u5c06\u4e0d\u4f7f\u7528\u7d22\u5f15\u800c\u4f7f\u7528\u5168\u8868\u626b\u63cf\uff0e\u4e3e\u4f8b:<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/td>\n

\u4f4e\u6548\uff1a<\/p>\n

SELECT \u2026 FROM\u00a0 DEPT\u00a0 WHERE SAL * 12 > 25000;<\/p>\n

\u9ad8\u6548:<\/p>\n

SELECT \u2026 FROM DEPT WHERE SAL > 25000\/12;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0823\uff09 \u7528>=\u66ff\u4ee3><\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/td>\n

\u9ad8\u6548:<\/p>\n

SELECT * FROM\u00a0 EMP\u00a0 WHERE\u00a0 DEPTNO >=4<\/p>\n

\u4f4e\u6548:<\/p>\n

SELECT * FROM EMP WHERE DEPTNO >3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u4e24\u8005\u7684\u533a\u522b\u5728\u4e8e, \u524d\u8005DBMS\u5c06\u76f4\u63a5\u8df3\u5230\u7b2c\u4e00\u4e2aDEPT\u7b49\u4e8e4\u7684\u8bb0\u5f55\u800c\u540e\u8005\u5c06\u9996\u5148\u5b9a\u4f4d\u5230DEPTNO=3\u7684\u8bb0\u5f55\u5e76\u4e14\u5411\u524d\u626b\u63cf\u5230\u7b2c\u4e00\u4e2aDEPT\u5927\u4e8e3\u7684\u8bb0\u5f55\u3002<\/p>\n

\uff0824\uff09 \u7528UNION\u66ff\u6362OR (\u9002\u7528\u4e8e\u7d22\u5f15\u5217)<\/p>\n

\u901a\u5e38\u60c5\u51b5\u4e0b, \u7528UNION\u66ff\u6362WHERE\u5b50\u53e5\u4e2d\u7684OR\u5c06\u4f1a\u8d77\u5230\u8f83\u597d\u7684\u6548\u679c. \u5bf9\u7d22\u5f15\u5217\u4f7f\u7528OR\u5c06\u9020\u6210\u5168\u8868\u626b\u63cf. \u6ce8\u610f, \u4ee5\u4e0a\u89c4\u5219\u53ea\u9488\u5bf9\u591a\u4e2a\u7d22\u5f15\u5217\u6709\u6548. \u5982\u679c\u6709column\u6ca1\u6709\u88ab\u7d22\u5f15, \u67e5\u8be2\u6548\u7387\u53ef\u80fd\u4f1a\u56e0\u4e3a\u4f60\u6ca1\u6709\u9009\u62e9OR\u800c\u964d\u4f4e. \u5728\u4e0b\u9762\u7684\u4f8b\u5b50\u4e2d, LOC_ID \u548cREGION\u4e0a\u90fd\u5efa\u6709\u7d22\u5f15.<\/p>\n\n\n\n
1<\/p>\n

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4<\/p>\n

5<\/p>\n

6<\/p>\n

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8<\/p>\n

9<\/p>\n

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11<\/p>\n

12<\/td>\n

\u9ad8\u6548:<\/p>\n

SELECT LOC_ID , LOC_DESC , REGION<\/p>\n

FROM LOCATION<\/p>\n

WHERE LOC_ID = 10<\/p>\n

UNION<\/p>\n

SELECT LOC_ID , LOC_DESC , REGION<\/p>\n

FROM LOCATION<\/p>\n

WHERE REGION = \u201cMELBOURNE\u201d<\/p>\n

\u4f4e\u6548:<\/p>\n

SELECT LOC_ID , LOC_DESC , REGION<\/p>\n

FROM LOCATION<\/p>\n

WHERE LOC_ID = 10 OR REGION = \u201cMELBOURNE\u201d<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u5982\u679c\u4f60\u575a\u6301\u8981\u7528OR, \u90a3\u5c31\u9700\u8981\u8fd4\u56de\u8bb0\u5f55\u6700\u5c11\u7684\u7d22\u5f15\u5217\u5199\u5728\u6700\u524d\u9762.<\/p>\n

\uff0825\uff09 \u7528IN\u6765\u66ff\u6362OR<\/p>\n

\u8fd9\u662f\u4e00\u6761\u7b80\u5355\u6613\u8bb0\u7684\u89c4\u5219\uff0c\u4f46\u662f\u5b9e\u9645\u7684\u6267\u884c\u6548\u679c\u8fd8\u987b\u68c0\u9a8c\uff0c\u5728ORACLE8i\u4e0b\uff0c\u4e24\u8005\u7684\u6267\u884c\u8def\u5f84\u4f3c\u4e4e\u662f\u76f8\u540c\u7684\uff0e<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/td>\n

\u4f4e\u6548:<\/p>\n

SELECT\u2026. FROM LOCATION WHERE LOC_ID = 10 OR LOC_ID = 20 OR LOC_ID = 30<\/p>\n

\u9ad8\u6548<\/p>\n

SELECT\u2026 FROM LOCATION WHERE LOC_IN\u00a0 IN (10,20,30);<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0826\uff09 \u907f\u514d\u5728\u7d22\u5f15\u5217\u4e0a\u4f7f\u7528IS NULL\u548cIS NOT NULL<\/p>\n

\u907f\u514d\u5728\u7d22\u5f15\u4e2d\u4f7f\u7528\u4efb\u4f55\u53ef\u4ee5\u4e3a\u7a7a\u7684\u5217\uff0cORACLE\u5c06\u65e0\u6cd5\u4f7f\u7528\u8be5\u7d22\u5f15\uff0e\u5bf9\u4e8e\u5355\u5217\u7d22\u5f15\uff0c\u5982\u679c\u5217\u5305\u542b\u7a7a\u503c\uff0c\u7d22\u5f15\u4e2d\u5c06\u4e0d\u5b58\u5728\u6b64\u8bb0\u5f55. \u5bf9\u4e8e\u590d\u5408\u7d22\u5f15\uff0c\u5982\u679c\u6bcf\u4e2a\u5217\u90fd\u4e3a\u7a7a\uff0c\u7d22\u5f15\u4e2d\u540c\u6837\u4e0d\u5b58\u5728\u6b64\u8bb0\u5f55. \u5982\u679c\u81f3\u5c11\u6709\u4e00\u4e2a\u5217\u4e0d\u4e3a\u7a7a\uff0c\u5219\u8bb0\u5f55\u5b58\u5728\u4e8e\u7d22\u5f15\u4e2d\uff0e\u4e3e\u4f8b: \u5982\u679c\u552f\u4e00\u6027\u7d22\u5f15\u5efa\u7acb\u5728\u8868\u7684A\u5217\u548cB\u5217\u4e0a, \u5e76\u4e14\u8868\u4e2d\u5b58\u5728\u4e00\u6761\u8bb0\u5f55\u7684A,B\u503c\u4e3a(123,null) , ORACLE\u5c06\u4e0d\u63a5\u53d7\u4e0b\u4e00\u6761\u5177\u6709\u76f8\u540cA,B\u503c\uff08123,null\uff09\u7684\u8bb0\u5f55(\u63d2\u5165). \u7136\u800c\u5982\u679c\u6240\u6709\u7684\u7d22\u5f15\u5217\u90fd\u4e3a\u7a7a\uff0cORACLE\u5c06\u8ba4\u4e3a\u6574\u4e2a\u952e\u503c\u4e3a\u7a7a\u800c\u7a7a\u4e0d\u7b49\u4e8e\u7a7a. \u56e0\u6b64\u4f60\u53ef\u4ee5\u63d2\u51651000 \u6761\u5177\u6709\u76f8\u540c\u952e\u503c\u7684\u8bb0\u5f55,\u5f53\u7136\u5b83\u4eec\u90fd\u662f\u7a7a! \u56e0\u4e3a\u7a7a\u503c\u4e0d\u5b58\u5728\u4e8e\u7d22\u5f15\u5217\u4e2d,\u6240\u4ee5WHERE\u5b50\u53e5\u4e2d\u5bf9\u7d22\u5f15\u5217\u8fdb\u884c\u7a7a\u503c\u6bd4\u8f83\u5c06\u4f7fORACLE\u505c\u7528\u8be5\u7d22\u5f15.<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/td>\n

\u4f4e\u6548: (\u7d22\u5f15\u5931\u6548)<\/p>\n

SELECT \u2026 FROM\u00a0 DEPARTMENT\u00a0 WHERE\u00a0 DEPT_CODE IS NOT NULL;<\/p>\n

\u9ad8\u6548: (\u7d22\u5f15\u6709\u6548)<\/p>\n

SELECT \u2026 FROM\u00a0 DEPARTMENT\u00a0 WHERE\u00a0 DEPT_CODE >=0;<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0827\uff09 \u603b\u662f\u4f7f\u7528\u7d22\u5f15\u7684\u7b2c\u4e00\u4e2a\u5217\uff1a<\/p>\n

\u5982\u679c\u7d22\u5f15\u662f\u5efa\u7acb\u5728\u591a\u4e2a\u5217\u4e0a, \u53ea\u6709\u5728\u5b83\u7684\u7b2c\u4e00\u4e2a\u5217(leading column)\u88abwhere\u5b50\u53e5\u5f15\u7528\u65f6,\u4f18\u5316\u5668\u624d\u4f1a\u9009\u62e9\u4f7f\u7528\u8be5\u7d22\u5f15. \u8fd9\u4e5f\u662f\u4e00\u6761\u7b80\u5355\u800c\u91cd\u8981\u7684\u89c4\u5219\uff0c\u5f53\u4ec5\u5f15\u7528\u7d22\u5f15\u7684\u7b2c\u4e8c\u4e2a\u5217\u65f6,\u4f18\u5316\u5668\u4f7f\u7528\u4e86\u5168\u8868\u626b\u63cf\u800c\u5ffd\u7565\u4e86\u7d22\u5f15\u3002<\/p>\n

\uff0828\uff09 \u7528UNION-ALL \u66ff\u6362UNION ( \u5982\u679c\u6709\u53ef\u80fd\u7684\u8bdd)\uff1a<\/p>\n

\u5f53SQL \u8bed\u53e5\u9700\u8981UNION\u4e24\u4e2a\u67e5\u8be2\u7ed3\u679c\u96c6\u5408\u65f6,\u8fd9\u4e24\u4e2a\u7ed3\u679c\u96c6\u5408\u4f1a\u4ee5UNION-ALL\u7684\u65b9\u5f0f\u88ab\u5408\u5e76, \u7136\u540e\u5728\u8f93\u51fa\u6700\u7ec8\u7ed3\u679c\u524d\u8fdb\u884c\u6392\u5e8f. \u5982\u679c\u7528UNION ALL\u66ff\u4ee3UNION, \u8fd9\u6837\u6392\u5e8f\u5c31\u4e0d\u662f\u5fc5\u8981\u4e86. \u6548\u7387\u5c31\u4f1a\u56e0\u6b64\u5f97\u5230\u63d0\u9ad8. \u9700\u8981\u6ce8\u610f\u7684\u662f\uff0cUNION ALL \u5c06\u91cd\u590d\u8f93\u51fa\u4e24\u4e2a\u7ed3\u679c\u96c6\u5408\u4e2d\u76f8\u540c\u8bb0\u5f55. \u56e0\u6b64\u5404\u4f4d\u8fd8\u662f\u8981\u4ece\u4e1a\u52a1\u9700\u6c42\u5206\u6790\u4f7f\u7528UNION ALL\u7684\u53ef\u884c\u6027. UNION \u5c06\u5bf9\u7ed3\u679c\u96c6\u5408\u6392\u5e8f,\u8fd9\u4e2a\u64cd\u4f5c\u4f1a\u4f7f\u7528\u5230SORT_AREA_SIZE\u8fd9\u5757\u5185\u5b58. \u5bf9\u4e8e\u8fd9\u5757\u5185\u5b58\u7684\u4f18\u5316\u4e5f\u662f\u76f8\u5f53\u91cd\u8981\u7684. \u4e0b\u9762\u7684SQL\u53ef\u4ee5\u7528\u6765\u67e5\u8be2\u6392\u5e8f\u7684\u6d88\u8017\u91cf<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/p>\n

5<\/p>\n

6<\/p>\n

7<\/p>\n

8<\/p>\n

9<\/p>\n

10<\/p>\n

11<\/p>\n

12<\/p>\n

13<\/p>\n

14<\/p>\n

15<\/p>\n

16<\/td>\n

\u4f4e\u6548\uff1a<\/p>\n

SELECT\u00a0 ACCT_NUM, BALANCE_AMT<\/p>\n

FROM\u00a0 DEBIT_TRANSACTIONS<\/p>\n

WHERE TRAN_DATE = ’31-DEC-95′<\/p>\n

UNION<\/p>\n

SELECT ACCT_NUM, BALANCE_AMT<\/p>\n

FROM DEBIT_TRANSACTIONS<\/p>\n

WHERE TRAN_DATE = ’31-DEC-95′<\/p>\n

\u9ad8\u6548:<\/p>\n

SELECT ACCT_NUM, BALANCE_AMT<\/p>\n

FROM DEBIT_TRANSACTIONS<\/p>\n

WHERE TRAN_DATE = ’31-DEC-95′<\/p>\n

UNION ALL<\/p>\n

SELECT ACCT_NUM, BALANCE_AMT<\/p>\n

FROM DEBIT_TRANSACTIONS<\/p>\n

WHERE TRAN_DATE = ’31-DEC-95′<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0829\uff09 \u7528WHERE\u66ff\u4ee3ORDER BY\uff1a<\/p>\n

ORDER BY \u5b50\u53e5\u53ea\u5728\u4e24\u79cd\u4e25\u683c\u7684\u6761\u4ef6\u4e0b\u4f7f\u7528\u7d22\u5f15.<\/p>\n

ORDER BY\u4e2d\u6240\u6709\u7684\u5217\u5fc5\u987b\u5305\u542b\u5728\u76f8\u540c\u7684\u7d22\u5f15\u4e2d\u5e76\u4fdd\u6301\u5728\u7d22\u5f15\u4e2d\u7684\u6392\u5217\u987a\u5e8f.<\/p>\n

ORDER BY\u4e2d\u6240\u6709\u7684\u5217\u5fc5\u987b\u5b9a\u4e49\u4e3a\u975e\u7a7a.<\/p>\n

WHERE\u5b50\u53e5\u4f7f\u7528\u7684\u7d22\u5f15\u548cORDER BY\u5b50\u53e5\u4e2d\u6240\u4f7f\u7528\u7684\u7d22\u5f15\u4e0d\u80fd\u5e76\u5217.<\/p>\n

\u4f8b\u5982:<\/p>\n

\u8868DEPT\u5305\u542b\u4ee5\u4e0b\u5217:<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/td>\n

DEPT_CODE PK NOT NULL<\/p>\n

DEPT_DESC NOT NULL<\/p>\n

DEPT_TYPE NULL<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/td>\n

\u4f4e\u6548: (\u7d22\u5f15\u4e0d\u88ab\u4f7f\u7528)<\/p>\n

SELECT DEPT_CODE FROM\u00a0 DEPT\u00a0 ORDER BY\u00a0 DEPT_TYPE<\/p>\n

\u9ad8\u6548: (\u4f7f\u7528\u7d22\u5f15)<\/p>\n

SELECT DEPT_CODE\u00a0 FROM\u00a0 DEPT\u00a0 WHERE\u00a0 DEPT_TYPE > 0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\uff0830\uff09 \u907f\u514d\u6539\u53d8\u7d22\u5f15\u5217\u7684\u7c7b\u578b:<\/p>\n

\u5f53\u6bd4\u8f83\u4e0d\u540c\u6570\u636e\u7c7b\u578b\u7684\u6570\u636e\u65f6, ORACLE\u81ea\u52a8\u5bf9\u5217\u8fdb\u884c\u7b80\u5355\u7684\u7c7b\u578b\u8f6c\u6362.<\/p>\n

\u5047\u8bbe EMPNO\u662f\u4e00\u4e2a\u6570\u503c\u7c7b\u578b\u7684\u7d22\u5f15\u5217.<\/p>\n\n\n\n
1<\/td>\nSELECT \u2026\u00a0 FROM EMP\u00a0 WHERE\u00a0 EMPNO = \u2018123′<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u5b9e\u9645\u4e0a,\u7ecf\u8fc7ORACLE\u7c7b\u578b\u8f6c\u6362, \u8bed\u53e5\u8f6c\u5316\u4e3a:<\/p>\n\n\n\n
1<\/td>\nSELECT \u2026\u00a0 FROM EMP\u00a0 WHERE\u00a0 EMPNO = TO_NUMBER(\u2018123′)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u5e78\u8fd0\u7684\u662f,\u7c7b\u578b\u8f6c\u6362\u6ca1\u6709\u53d1\u751f\u5728\u7d22\u5f15\u5217\u4e0a,\u7d22\u5f15\u7684\u7528\u9014\u6ca1\u6709\u88ab\u6539\u53d8.<\/p>\n

\u73b0\u5728,\u5047\u8bbeEMP_TYPE\u662f\u4e00\u4e2a\u5b57\u7b26\u7c7b\u578b\u7684\u7d22\u5f15\u5217.<\/p>\n\n\n\n
1<\/td>\nSELECT \u2026\u00a0 FROM EMP\u00a0 WHERE EMP_TYPE = 123<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u8fd9\u4e2a\u8bed\u53e5\u88abORACLE\u8f6c\u6362\u4e3a:<\/p>\n\n\n\n
1<\/td>\nSELECT \u2026\u00a0 FROM EMP\u00a0 WHERE TO_NUMBER(EMP_TYPE)=123<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u56e0\u4e3a\u5185\u90e8\u53d1\u751f\u7684\u7c7b\u578b\u8f6c\u6362, \u8fd9\u4e2a\u7d22\u5f15\u5c06\u4e0d\u4f1a\u88ab\u7528\u5230! \u4e3a\u4e86\u907f\u514dORACLE\u5bf9\u4f60\u7684SQL\u8fdb\u884c\u9690\u5f0f\u7684\u7c7b\u578b\u8f6c\u6362, \u6700\u597d\u628a\u7c7b\u578b\u8f6c\u6362\u7528\u663e\u5f0f\u8868\u73b0\u51fa\u6765. \u6ce8\u610f\u5f53\u5b57\u7b26\u548c\u6570\u503c\u6bd4\u8f83\u65f6, ORACLE\u4f1a\u4f18\u5148\u8f6c\u6362\u6570\u503c\u7c7b\u578b\u5230\u5b57\u7b26\u7c7b\u578b\u3002<\/p>\n

\u5206\u6790<\/p>\n\n\n\n
1<\/td>\nselect\u00a0\u00a0 emp_name\u00a0\u00a0 form\u00a0\u00a0 employee\u00a0\u00a0 where\u00a0\u00a0 salary\u00a0\u00a0 >\u00a0\u00a0 3000<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u5728\u6b64\u8bed\u53e5\u4e2d\u82e5salary\u662fFloat\u7c7b\u578b\u7684\uff0c\u5219\u4f18\u5316\u5668\u5bf9\u5176\u8fdb\u884c\u4f18\u5316\u4e3aConvert(float,3000)\uff0c\u56e0\u4e3a3000\u662f\u4e2a\u6574\u6570\uff0c\u6211\u4eec\u5e94\u5728\u7f16\u7a0b\u65f6\u4f7f\u75283000.0\u800c\u4e0d\u8981\u7b49\u8fd0\u884c\u65f6\u8ba9DBMS\u8fdb\u884c\u8f6c\u5316\u3002\u540c\u6837\u5b57\u7b26\u548c\u6574\u578b\u6570\u636e\u7684\u8f6c\u6362\u3002<\/p>\n

\uff0831\uff09 \u9700\u8981\u5f53\u5fc3\u7684WHERE\u5b50\u53e5:<\/p>\n

\u67d0\u4e9bSELECT \u8bed\u53e5\u4e2d\u7684WHERE\u5b50\u53e5\u4e0d\u4f7f\u7528\u7d22\u5f15. \u8fd9\u91cc\u6709\u4e00\u4e9b\u4f8b\u5b50.<\/p>\n

\u5728\u4e0b\u9762\u7684\u4f8b\u5b50\u91cc, (1)\u2018!=\u2019 \u5c06\u4e0d\u4f7f\u7528\u7d22\u5f15. \u8bb0\u4f4f, \u7d22\u5f15\u53ea\u80fd\u544a\u8bc9\u4f60\u4ec0\u4e48\u5b58\u5728\u4e8e\u8868\u4e2d, \u800c\u4e0d\u80fd\u544a\u8bc9\u4f60\u4ec0\u4e48\u4e0d\u5b58\u5728\u4e8e\u8868\u4e2d. (2) \u2018 \u00a6 \u00a6\u2019\u662f\u5b57\u7b26\u8fde\u63a5\u51fd\u6570. \u5c31\u8c61\u5176\u4ed6\u51fd\u6570\u90a3\u6837, \u505c\u7528\u4e86\u7d22\u5f15. (3) \u2018+\u2019\u662f\u6570\u5b66\u51fd\u6570. \u5c31\u8c61\u5176\u4ed6\u6570\u5b66\u51fd\u6570\u90a3\u6837, \u505c\u7528\u4e86\u7d22\u5f15. (4)\u76f8\u540c\u7684\u7d22\u5f15\u5217\u4e0d\u80fd\u4e92\u76f8\u6bd4\u8f83,\u8fd9\u5c06\u4f1a\u542f\u7528\u5168\u8868\u626b\u63cf.<\/p>\n

\uff0832\uff09 a. \u5982\u679c\u68c0\u7d22\u6570\u636e\u91cf\u8d85\u8fc730%\u7684\u8868\u4e2d\u8bb0\u5f55\u6570.\u4f7f\u7528\u7d22\u5f15\u5c06\u6ca1\u6709\u663e\u8457\u7684\u6548\u7387\u63d0\u9ad8. b. \u5728\u7279\u5b9a\u60c5\u51b5\u4e0b, \u4f7f\u7528\u7d22\u5f15\u4e5f\u8bb8\u4f1a\u6bd4\u5168\u8868\u626b\u63cf\u6162, \u4f46\u8fd9\u662f\u540c\u4e00\u4e2a\u6570\u91cf\u7ea7\u4e0a\u7684\u533a\u522b. \u800c\u901a\u5e38\u60c5\u51b5\u4e0b,\u4f7f\u7528\u7d22\u5f15\u6bd4\u5168\u8868\u626b\u63cf\u8981\u5757\u51e0\u500d\u4e43\u81f3\u51e0\u5343\u500d!<\/p>\n

\uff0833\uff09 \u907f\u514d\u4f7f\u7528\u8017\u8d39\u8d44\u6e90\u7684\u64cd\u4f5c\uff1a<\/p>\n

\u5e26\u6709DISTINCT,UNION,MINUS,INTERSECT,ORDER BY\u7684SQL\u8bed\u53e5\u4f1a\u542f\u52a8SQL\u5f15\u64ce\u6267\u884c\u8017\u8d39\u8d44\u6e90\u7684\u6392\u5e8f(SORT)\u529f\u80fd. DISTINCT\u9700\u8981\u4e00\u6b21\u6392\u5e8f\u64cd\u4f5c, \u800c\u5176\u4ed6\u7684\u81f3\u5c11\u9700\u8981\u6267\u884c\u4e24\u6b21\u6392\u5e8f. \u901a\u5e38, \u5e26\u6709UNION, MINUS , INTERSECT\u7684SQL\u8bed\u53e5\u90fd\u53ef\u4ee5\u7528\u5176\u4ed6\u65b9\u5f0f\u91cd\u5199. \u5982\u679c\u4f60\u7684\u6570\u636e\u5e93\u7684SORT_AREA_SIZE\u8c03\u914d\u5f97\u597d, \u4f7f\u7528UNION , MINUS, INTERSECT\u4e5f\u662f\u53ef\u4ee5\u8003\u8651\u7684, \u6bd5\u7adf\u5b83\u4eec\u7684\u53ef\u8bfb\u6027\u5f88\u5f3a\u3002<\/p>\n

\uff0834\uff09 \u4f18\u5316GROUP BY\uff1a<\/p>\n

\u63d0\u9ad8GROUP BY \u8bed\u53e5\u7684\u6548\u7387, \u53ef\u4ee5\u901a\u8fc7\u5c06\u4e0d\u9700\u8981\u7684\u8bb0\u5f55\u5728GROUP BY \u4e4b\u524d\u8fc7\u6ee4\u6389.\u4e0b\u9762\u4e24\u4e2a\u67e5\u8be2\u8fd4\u56de\u76f8\u540c\u7ed3\u679c\u4f46\u7b2c\u4e8c\u4e2a\u660e\u663e\u5c31\u5feb\u4e86\u8bb8\u591a.<\/p>\n\n\n\n
1<\/p>\n

2<\/p>\n

3<\/p>\n

4<\/p>\n

5<\/p>\n

6<\/p>\n

7<\/p>\n

8<\/p>\n

9<\/p>\n

10<\/p>\n

11<\/p>\n

12<\/td>\n

\u4f4e\u6548:<\/p>\n

SELECT JOB , AVG(SAL)<\/p>\n

FROM EMP<\/p>\n

GROUP by JOB<\/p>\n

HAVING JOB = \u2018PRESIDENT’<\/p>\n

OR JOB = \u2018MANAGER’<\/p>\n

\u9ad8\u6548:<\/p>\n

SELECT JOB , AVG(SAL)<\/p>\n

FROM EMP<\/p>\n

WHERE JOB = \u2018PRESIDENT’<\/p>\n

OR JOB = \u2018MANAGER’<\/p>\n

GROUP by JOB<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

\u8f6c\u8f7d\u8bf7\u6ce8\u660e\uff1a\u8d6b\u975e\u57df<\/a> » ORACLE\u6570\u636e\u5e93\u6027\u80fd\u4f18\u5316\u4e4bSQL\u8bed\u53e5\u4f18\u5316<\/a><\/p>","protected":false},"excerpt":{"rendered":"

\u4e00\u3001\u95ee\u9898\u7684\u63d0\u51fa \u5728\u5e94\u7528\u7cfb\u7edf\u5f00\u53d1\u521d\u671f\uff0c\u7531\u4e8e\u5f00\u53d1\u6570\u636e\u5e93\u6570\u636e\u6bd4\u8f83\u5c11\uff0c\u5bf9\u4e8e\u67e5\u8be2SQL\u8bed\u53e5\uff0c\u590d\u6742\u89c6\u56fe\u7684\u7684\u7f16\u5199\u7b49\u4f53\u4f1a\u4e0d\u51faSQL\u8bed\u53e5\u5404\u79cd\u5199\u6cd5\u7684\u6027\u80fd\u4f18\u52a3\uff0c\u4f46\u662f\u5982\u679c\u5c06\u5e94\u7528\u7cfb\u7edf\u63d0\u4ea4\u5b9e\u9645\u5e94\u7528\u540e\uff0c\u968f\u7740\u6570\u636e\u5e93\u4e2d\u6570\u636e\u7684\u589e\u52a0\uff0c\u7cfb\u7edf\u7684\u54cd\u5e94\u901f\u5ea6\u5c31\u6210\u4e3a\u76ee\u524d\u7cfb\u7edf\u9700\u8981\u89e3\u51b3\u7684\u6700\u4e3b\u8981\u7684\u95ee\u9898\u4e4b\u4e00 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28],"tags":[51,216,218],"class_list":["post-647","post","type-post","status-publish","format-standard","hentry","category-unix","tag-oracle","tag-sql","tag-218"],"_links":{"self":[{"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=\/wp\/v2\/posts\/647","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=647"}],"version-history":[{"count":2,"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=\/wp\/v2\/posts\/647\/revisions"}],"predecessor-version":[{"id":649,"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=\/wp\/v2\/posts\/647\/revisions\/649"}],"wp:attachment":[{"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=647"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=647"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.hefeiyu.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=647"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}