{"id":41371,"date":"2023-01-06T14:31:07","date_gmt":"2023-03-27T22:42:25","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/%e4%bb%a50%e4%b8%ba%e8%b5%b7%e5%a7%8b%e7%9a%84postgresql\/"},"modified":"2024-04-29T08:45:43","modified_gmt":"2024-04-29T00:45:43","slug":"%e4%bb%a50%e4%b8%ba%e8%b5%b7%e5%a7%8b%e7%9a%84postgresql","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/%e4%bb%a50%e4%b8%ba%e8%b5%b7%e5%a7%8b%e7%9a%84postgresql\/","title":{"rendered":"\u4ee5&#8221;0()&#8221;\u4e3a\u8d77\u59cb\u7684PostgreSQL"},"content":{"rendered":"<h2>\u9996\u5148<\/h2>\n<p>\u5bf9\u4e0d\u8d77\uff0c\u8fd9\u4e0d\u662f\u4e00\u7bc7\u4ece\u96f6\u5f00\u59cb\u5b66\u4e60PostgreSQL\u7684\u5165\u95e8\u6587\u7ae0\u3002<br \/>\n\u5f88\u62b1\u6b49\u6807\u9898\u53ef\u80fd\u8bef\u5bfc\u4e86\u3002<\/p>\n<p>\u6211\u5c06\u5728PostgreSQL\u4e2d\u5199\u5173\u4e8e0\u7684\u6545\u4e8b\u3002<\/p>\n<h2>\u6700\u5c0f\u7684\u684c\u5b50\u8bbe\u7f6e<\/h2>\n<p>SQL\u662f\u4e00\u79cd\u7528\u4e8e\u4ece\u591a\u4e2a\u8868\u4e2d\u83b7\u53d6\u4e00\u4e2a\u8868\u683c\u7684\u8bed\u8a00\u3002<br \/>\nSQL\u6240\u6d89\u53ca\u7684\u8868\u683c\u7ed3\u6784\u7531\u884c\u548c\u5217\u7ec4\u6210\u3002<\/p>\n<div>\n<div class=\"post-table\">\u52171\u52172\u52173\u884c1\u884c1\u884c1\u884c2\u884c2\u884c2\u884c3\u884c3\u884c3<\/div>\n<\/div>\n<p>\u6700\u5c0f\u7684\u8868\u683c\u6784\u6210\u662f\u4ec0\u4e48\uff1f\u7406\u8bba\u4e0a\u6765\u8bf4\uff0c0\u884c0\u5217\u7684\u8868\u683c\u662f\u6700\u5c0f\u7684\u8868\u683c\u6784\u6210\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c0\u5e76\u4e0d\u662f\u6307\u6570\u7ec4\u4e2d\u7684\u7b2c\u4e00\u4e2a\u5143\u7d20[0]\uff0c\u800c\u662f\u7c7b\u4f3c\u4e8e\u957f\u5ea6\u4e3a0\u7684\u6570\u7ec4[]\u3002<\/p>\n<h2>\u884c0\u7684\u684c\u5b50 de zhu\u014d zi)<\/h2>\n<p>\u884c\u6570\u4e3a0\u7684\u8868\u662f\u975e\u5e38\u5e38\u89c1\u7684\u3002\u5728\u901a\u5e38\u7684\u641c\u7d22\u4e2d\uff0c\u5982\u679c\u641c\u7d22\u6761\u4ef6\u4e0d\u5339\u914d\uff0c\u5219\u4f1a\u8fd4\u56de\u4e00\u4e2a\u884c\u6570\u4e3a0\u7684\u7ed3\u679c\u8868\uff1b\u800c\u4f7f\u7528CREATE TABLE\u521b\u5efa\u7684\u8868\uff0c\u884c\u6570\u4e5f\u662f0\u3002<\/p>\n<h2>\u96f6\u5217\u7684\u8868\u683c<\/h2>\n<p>\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u4e0d\u4f1a\u770b\u5230\u5177\u6709\u96f6\u5217\u7684\u8868\u3002\u56e0\u4e3a\u96f6\u5217\u7684\u8868\u65e0\u6cd5\u5b58\u50a8\u4efb\u4f55\u503c\uff0c\u6240\u4ee5\u6ca1\u6709\u5fc5\u8981\u7279\u610f\u521b\u5efa\u5b83\u4eec\u3002<br \/>\n\u5728\u6807\u51c6\u7684SQL\u4e2d\uff0c\u4f3c\u4e4e\u65e0\u6cd5\u521b\u5efa\u96f6\u5217\u7684\u8868\uff0c\u5927\u591a\u6570\u5173\u7cfb\u578b\u6570\u636e\u5e93\u4e5f\u65e0\u6cd5\u521b\u5efa\u96f6\u5217\u7684\u8868\u3002<\/p>\n<p>\u7136\u800c\uff0c\u5728PostgreSQL\u4e2d\uff0c\u60a8\u53ef\u4ee5\u521b\u5efa\u5177\u67090\u5217\u7684\u8868\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">CREATE<\/span> <span class=\"k\">TABLE<\/span> <span class=\"n\">zero_column<\/span> <span class=\"p\">();<\/span>\r\n<\/code><\/pre>\n<p>PostgreSQL 7.4\u660e\u786e\u8868\u793a\u53ef\u4ee5\u521b\u5efa\u96f6\u5217\u7684\u8868\u3002<\/p>\n<p>\u4f5c\u4e3a\u4e00\u79cd\u601d\u8003\u65b9\u5f0f\uff0c\u901a\u8fc7\u4f7f\u7528 ALTER TABLE \u8868\u540d DROP COLUMN \u5217\u540d \u53ef\u4ee5\u5220\u9664\u5217\u5e76\u521b\u5efa\u4e00\u4e2a\u5217\u6570\u4e3a0\u7684\u8868\u3002\u56e0\u6b64\uff0c\u4e3a\u4e86\u907f\u514d\u51fa\u73b0\u5373\u4f7f\u5b58\u5728\u5217\u4e5f\u4e0d\u6210\u4e3a\u5217\u6570\u4e3a0\u7684\u60c5\u51b5\uff0cPostgreSQL\u9009\u62e9\u5141\u8bb8\u5217\u6570\u4e3a0\u7684\u60c5\u51b5\u3002<\/p>\n<p>\u56e0\u6b64\uff0c\u5728\u5176\u4ed6\u7f16\u7a0b\u8bed\u8a00\u4e2d\u7ecf\u5e38\u4f1a\u521b\u5efa\u4e00\u4e2a\u7a7a\u7684\u53ef\u53d8\u957f\u5ea6\u6570\u7ec4\uff08\u5207\u7247\uff09\u5e76\u7a0d\u540e\u5411\u5176\u4e2d\u6dfb\u52a0\u5143\u7d20\u7684\u4fbf\u5229\u6027\uff0c\u7406\u8bba\u4e0a\u5728PostgreSQL\u4e2d\u4e5f\u53ef\u4ee5\u9996\u5148\u521b\u5efa\u4e00\u4e2a\u7a7a\u8868\uff0c\u7136\u540e\u9010\u6b65\u6dfb\u52a0\u5217\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">CREATE<\/span> <span class=\"k\">TABLE<\/span> <span class=\"n\">add_user<\/span> <span class=\"p\">();<\/span>\r\n<span class=\"k\">ALTER<\/span> <span class=\"k\">TABLE<\/span> <span class=\"n\">add_user<\/span> <span class=\"k\">ADD<\/span> <span class=\"k\">COLUMN<\/span> <span class=\"n\">id<\/span> <span class=\"nb\">SERIAL<\/span><span class=\"p\">;<\/span>\r\n<span class=\"k\">ALTER<\/span> <span class=\"k\">TABLE<\/span> <span class=\"n\">add_user<\/span> <span class=\"k\">ADD<\/span> <span class=\"k\">COLUMN<\/span> <span class=\"n\">name<\/span> <span class=\"nb\">TEXT<\/span><span class=\"p\">;<\/span>\r\n<span class=\"k\">ALTER<\/span> <span class=\"k\">TABLE<\/span> <span class=\"n\">add_user<\/span> <span class=\"k\">ADD<\/span> <span class=\"k\">COLUMN<\/span> <span class=\"n\">age<\/span> <span class=\"nb\">INT<\/span><span class=\"p\">;<\/span>\r\n<\/code><\/pre>\n<p>\u55ef\uff0c\u7531\u4e8e\u5404\u79cd\u60c5\u51b5\uff0c\u901a\u5e38\u60c5\u51b5\u4e0b\u6211\u4eec\u4e0d\u8fd9\u6837\u505a\uff0c\u5bf9\u4e8e\u6570\u636e\u5e93\u7ba1\u7406\u5458\u6765\u8bf4\u53ef\u80fd\u4f1a\u50cf\u662f\u5669\u68a6\u4e00\u6837\u770b\u5f85&#8230;<\/p>\n<h2>INSERT\u662f\u5426\u652f\u6301\u5728\u7b2c0\u5217\u8fdb\u884c\u64cd\u4f5c\uff1f<\/h2>\n<p>\u6240\u4ee5\uff0c\u4e5f\u8bb8\u4f60\u53ef\u80fd\u4e0d\u660e\u767d\u8fd9\u4e2a\u610f\u601d\uff0c\u4f46\u662f\u4f60\u4e5f\u53ef\u4ee5\u5728\u5217\u4e3a0\u7684\u8868\u4e2d\u6dfb\u52a0\u884c\u3002<br \/>\n\u7136\u800c\uff0c\u4f60\u4e0d\u80fd\u4f7f\u7528INSERT INTO zero_column VALUES ();\u6216INSERT INTO zero_columns () VALUES ();\u6765\u6dfb\u52a0\u3002<br \/>\n\u4f60\u77e5\u9053\u8be5\u5982\u4f55\u5199\u5417\uff1f\u8bf7\u60f3\u4e00\u60f3\uff0c\u6211\u4f1a\u6298\u53e0\u8d77\u6765\u7b49\u4f60\u3002<\/p>\n<details>\u63d2\u5165\u9ed8\u8ba4\u503c\u5230\u96f6\u5217\uff1b<br \/>\n\u5411\u96f6\u5217\u63d2\u5165\u9ed8\u8ba4\u503c\u3002<\/details>\n<p>\u6b64\u5916\uff0c\u73b0\u5728\u4e5f\u53ef\u4ee5\u4f7f\u7528SELECT\u5c06\u5217\u8868\u6e05\u7a7a\uff08\u6b64\u529f\u80fd\u4ecePostgreSQL 9.4\u7248\u672c\u5f00\u59cb\uff09\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">SELECT<\/span> <span class=\"k\">FROM<\/span> <span class=\"n\">anther_table<\/span><span class=\"p\">;<\/span>\r\n<\/code><\/pre>\n<p>\u90a3\u4e48\uff0c\u8fd9\u662f\u5728\u7b2c0\u5217\u7684\u8868\u4e2d\u6dfb\u52a0\u884c\u7684\u53e6\u4e00\u79cd\u65b9\u6cd5\u3002<\/p>\n<details>\u901a\u8fc7\u4ee5\u4e0b\u65b9\u6cd5\uff0c\u5728\u7b2c0\u5217\u63d2\u5165\u884c\uff1a<br \/>\nINSERT INTO zero_column SELECT FROM anther_table;\u4f7f\u7528\u8fd9\u79cd\u65b9\u5f0f\u53ef\u4ee5\u521b\u5efa\u4e00\u4e2a\u6709\u591a\u884c\u96f6\u5217\u7684\u8868\u3002<\/p>\n<\/details>\n<h2>\u6700\u5c0f\u7684\u9009\u62e9<\/h2>\n<p>\u5df2\u77e5SELECT\u8bed\u53e5\u4e2d\u53ef\u4ee5\u7701\u7565FROM\u5b50\u53e5\u3002\u7531\u4e8eSELECT\u5217\u8868\u4e5f\u53ef\u4ee5\u4e3a\u7a7a\uff0c\u56e0\u6b64\u6700\u7b80\u5355\u7684SELECT\u8bed\u53e5\u5982\u4e0b\uff1a<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">SELECT<\/span><span class=\"p\">;<\/span>\r\n<\/code><\/pre>\n<p>\u5982\u679c\u5728psql\u4e2d\u6267\u884c\u8fd9\u4e2a\u547d\u4ee4\uff0c\u7ed3\u679c\u5c06\u5982\u4e0b\u6240\u793a\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"n\">postgres<\/span><span class=\"o\">=#<\/span> <span class=\"k\">SELECT<\/span><span class=\"p\">;<\/span>\r\n<span class=\"c1\">--<\/span>\r\n<span class=\"p\">(<\/span><span class=\"mi\">1<\/span> <span class=\"k\">row<\/span><span class=\"p\">)<\/span>\r\n<\/code><\/pre>\n<p>\u53ef\u80fd\u4f1a\u6709\u4eba\u5bf9\u7ed3\u679c\u4ea7\u751f\u7591\u95ee\u3002SELECT\u7684\u7ed3\u679c\u4e0d\u662f\u4e00\u4e2a0\u52170\u884c\u7684\u8868\uff0c\u800c\u662f\u4e00\u4e2a0\u52171\u884c\uff08row\uff09\u7684\u8868\u3002<br \/>\n\u5f53SELECT\u8bed\u53e5\u7701\u7565FROM\u5b50\u53e5\u65f6\uff0c\u901a\u5e38\u7528\u4e8e\u8fd4\u56de\u7c7b\u4f3cSELECT &#8216;TEST&#8217;\uff0c1+2\u8fd9\u6837\u7684\u5e38\u6570\u3002<br \/>\n\u6362\u53e5\u8bdd\u8bf4\uff0c\u5982\u679c\u5728SELECT\u8bed\u53e5\u4e2d\u7701\u7565FROM\u5b50\u53e5\uff0c\u53ef\u4ee5\u8003\u8651\u751f\u62101\u884c\uff08\u6216\u66f4\u591a\uff09\u7684\u8868\uff0c\u56e0\u6b64\u4f1a\u8fd4\u56de\u4e00\u4e2a0\u52171\u884c\u7684\u8868\u3002<\/p>\n<p>\u6709\u591a\u79cd\u65b9\u6cd5\u53ef\u4ee5\u5c06\u884c\u53d8\u4e3a0\uff0c\u5f53\u60f3\u8981\u8fd4\u56de0\u52170\u884c\u65f6\uff08\u867d\u7136\u6709\u51e0\u79cd\u65b9\u6cd5\u53ef\u9009\u62e9\uff09\uff0c\u6211\u60f3\u5230\u4e86\u4ee5\u4e0b\u7684\u89e3\u51b3\u65b9\u6848\u3002<\/p>\n<details>\u4ece\u8bed\u53e5\u7684\u89d2\u5ea6\u6765\u770b\uff0c\u8fd4\u56de0\u52170\u884c\u7684SELECT\u8bed\u53e5\u4f1a\u6bd4\u8fd4\u56de0\u52171\u884c\u66f4\u957f\uff0c\u8fd9\u662f\u5f88\u6709\u8da3\u7684\u3002<\/details>\n<div>\u987a\u4fbf\u63d0\u4e00\u4e0b\uff0c\u4f3c\u4e4e\u5728psql\u4e2d\uff0c\u5217\u6570\u4e3a0\u7684\u8868\u4e0d\u4f1a\u88ab\u663e\u793a\u51fa\u6765\uff08\u5305\u62ec\u6362\u884c\uff09\u3002<br \/>\nSELECT FROM zero_column ;<br \/>\n&#8212;<br \/>\n\uff086 \u884c\uff09\u8fd9\u662f\u5ba2\u6237\u7aef\u663e\u793a\u65b9\u5f0f\u7684\u95ee\u9898\uff0c\u5982\u679c\u7528\u6211\u7684trdsql\u4ee5JSON\u683c\u5f0f\u8f93\u51fa\uff0c\u5c06\u4f1a\u663e\u793a\u5982\u4e0b\uff1a<br \/>\n$ trdsql -driver postgres -ojson &#8220;SELECT FROM zero_column&#8221;<br \/>\n[<br \/>\n{},<br \/>\n{},<br \/>\n{},<br \/>\n{},<br \/>\n{},<br \/>\n{}<br \/>\n]<\/p>\n<\/div>\n<p>PostgreSQL\u867d\u7136\u652f\u6301\u96f6\u5217\uff0c\u4f46\u6839\u636eSQL\u6807\u51c6\uff08\u9664\u975e\u5185\u90e8\u7684\u60c5\u51b5\uff09\uff0c\u4e0d\u652f\u6301\u96f6\u5217\uff0c\u56e0\u6b64\u662f\u5426\u652f\u6301\u96f6\u5217\u53d6\u51b3\u4e8e\u8bed\u6cd5\u3002\u63a5\u4e0b\u6765\u6211\u4eec\u5c06\u5bf9\u6b64\u8fdb\u884c\u8ba8\u8bba\u3002<\/p>\n<h2>SELECT COUNT\u51fd\u6570\u662f\u5426\u652f\u63010\u5217\uff1f<\/h2>\n<p>\u53ef\u4ee5\u5c06 SELECT \u5217\u8868\u8bbe\u7f6e\u4e3a\u7a7a\uff0c\u4f46\u662f\u4e0d\u80fd\u5c06 COUNT \u51fd\u6570\u8bbe\u7f6e\u4e3a\u7a7a\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">SELECT<\/span> <span class=\"k\">count<\/span><span class=\"p\">()<\/span> <span class=\"k\">FROM<\/span> <span class=\"n\">zero_column<\/span> <span class=\"p\">;<\/span>\r\n<span class=\"n\">ERROR<\/span><span class=\"p\">:<\/span>  <span class=\"mi\">42809<\/span><span class=\"p\">:<\/span> <span class=\"k\">count<\/span><span class=\"p\">(<\/span><span class=\"o\">*<\/span><span class=\"p\">)<\/span> <span class=\"n\">must<\/span> <span class=\"n\">be<\/span> <span class=\"n\">used<\/span> <span class=\"k\">to<\/span> <span class=\"k\">call<\/span> <span class=\"n\">a<\/span> <span class=\"n\">parameterless<\/span> <span class=\"k\">aggregate<\/span> <span class=\"k\">function<\/span>\r\n<span class=\"n\">LINE<\/span> <span class=\"mi\">1<\/span><span class=\"p\">:<\/span> <span class=\"k\">SELECT<\/span> <span class=\"k\">count<\/span><span class=\"p\">()<\/span> <span class=\"k\">FROM<\/span> <span class=\"n\">zero_column<\/span> <span class=\"p\">;<\/span>\r\n               <span class=\"o\">^<\/span>\r\n<span class=\"k\">LOCATION<\/span><span class=\"p\">:<\/span>  <span class=\"n\">ParseFuncOrColumn<\/span><span class=\"p\">,<\/span> <span class=\"n\">parse_func<\/span><span class=\"p\">.<\/span><span class=\"k\">c<\/span><span class=\"p\">:<\/span><span class=\"mi\">788<\/span>\r\n<\/code><\/pre>\n<p>\u5728\u4f7f\u7528COUNT(*)\u51fd\u6570\u65f6\uff0c\u4f1a\u6b63\u786e\u8fd4\u56de\u884c\u6570\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">SELECT<\/span> <span class=\"k\">count<\/span><span class=\"p\">(<\/span><span class=\"o\">*<\/span><span class=\"p\">)<\/span> <span class=\"k\">FROM<\/span> <span class=\"n\">zero_column<\/span>\r\n <span class=\"k\">count<\/span> \r\n<span class=\"c1\">-------<\/span>\r\n     <span class=\"mi\">6<\/span>\r\n<span class=\"p\">(<\/span><span class=\"mi\">1<\/span> <span class=\"k\">row<\/span><span class=\"p\">)<\/span>\r\n<\/code><\/pre>\n<p>\u6211\u8ba4\u4e3a*\u662f\u6307\u5217\u8868\u7684\u6240\u6709\u5185\u5bb9\uff0c\u4f46\u5b9e\u9645\u4e0a\u66f4\u4e3a\u590d\u6742\u3002\u624b\u518c\u4e2d\u5199\u9053\u5982\u4e0b\uff1a<\/p>\n<blockquote><p>https:\/\/www.postgresql.jp\/document\/current\/html\/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS \u8fd9\u4e2a\u94fe\u63a5\u4ecb\u7ecd\u4e86\u5728\u4e00\u4e9b\u4e0a\u4e0b\u6587\u4e2d\u4f7f\u7528\u661f\u53f7\uff08*\uff09\u6765\u8868\u793a\u8868\u884c\u6216\u590d\u5408\u7c7b\u578b\u7684\u6240\u6709\u5b57\u6bb5\u3002\u6b64\u5916\uff0c\u5f53\u7528\u4f5c\u805a\u5408\u51fd\u6570\u7684\u53c2\u6570\u65f6\uff0c\u5b83\u8fd8\u6709\u4e00\u4e2a\u7279\u6b8a\u7684\u610f\u4e49\uff0c\u5373\u8868\u793a\u8be5\u805a\u5408\u4e0d\u9700\u8981\u663e\u5f0f\u53c2\u6570\u3002<\/p><\/blockquote>\n<p>COUNT\u662f\u4e00\u4e2a\u805a\u5408\u51fd\u6570\uff0c\u56e0\u6b64\u5177\u6709\u7279\u6b8a\u7684\u542b\u4e49\u3002<\/p>\n<h2>VALUES\u662f\u5426\u5bf9\u5e94\u4e8e\u7b2c0\u5217\uff1f<\/h2>\n<p>\u5728PostgreSQL\u4e2d\uff0c\u53ef\u4ee5\u5355\u72ec\u4f7f\u7528VALUES\u3002VALUES\u7528\u4e8e\u5c06\u5e38\u91cf\u8f6c\u6362\u4e3a\u8868\u683c\uff0c\u7c7b\u4f3c\u4e8e\u7701\u7565SELECT\u8bed\u53e5\u7684FROM\u5b50\u53e5\u65f6\u7684\u60c5\u51b5\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">VALUES<\/span><span class=\"p\">(<\/span><span class=\"mi\">1<\/span><span class=\"p\">,<\/span><span class=\"s1\">'a'<\/span><span class=\"p\">);<\/span>\r\n <span class=\"n\">column1<\/span> <span class=\"o\">|<\/span> <span class=\"n\">column2<\/span> \r\n<span class=\"c1\">---------+---------<\/span>\r\n       <span class=\"mi\">1<\/span> <span class=\"o\">|<\/span> <span class=\"n\">a<\/span>\r\n<span class=\"p\">(<\/span><span class=\"mi\">1<\/span> <span class=\"k\">row<\/span><span class=\"p\">)<\/span>\r\n<\/code><\/pre>\n<p>\u6211\u539f\u4ee5\u4e3a\u53ef\u4ee5\u4f7f\u7528VALUES\u6765\u521b\u5efa\u4e00\u4e2a\u6ca1\u6709\u5217\u7684\u8868\uff0c\u4f46\u662f\u51fa\u73b0\u4e86\u9519\u8bef\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">VALUES<\/span><span class=\"p\">();<\/span>\r\n<span class=\"n\">ERROR<\/span><span class=\"p\">:<\/span>  <span class=\"mi\">42601<\/span><span class=\"p\">:<\/span> <span class=\"n\">syntax<\/span> <span class=\"n\">error<\/span> <span class=\"k\">at<\/span> <span class=\"k\">or<\/span> <span class=\"n\">near<\/span> <span class=\"nv\">\")\"<\/span>\r\n<span class=\"n\">LINE<\/span> <span class=\"mi\">1<\/span><span class=\"p\">:<\/span> <span class=\"k\">values<\/span><span class=\"p\">();<\/span>\r\n               <span class=\"o\">^<\/span>\r\n<span class=\"k\">LOCATION<\/span><span class=\"p\">:<\/span>  <span class=\"n\">scanner_yyerror<\/span><span class=\"p\">,<\/span> <span class=\"n\">scan<\/span><span class=\"p\">.<\/span><span class=\"n\">l<\/span><span class=\"p\">:<\/span><span class=\"mi\">1176<\/span>\r\n<\/code><\/pre>\n<p>\u6211\u627e\u5230\u4e86\u5bfc\u81f4 INSERT INTO zero_column VALUES (); \u51fa\u9519\u7684\u539f\u56e0\u4e86\u3002<\/p>\n<h2>DELETE\u5bf9\u5e94\u4e8e\u7b2c0\u5217\u5417\uff1f<\/h2>\n<p>\u5982\u679c\u7701\u7565WHERE\u5b50\u53e5\uff0cDELETE\u8bed\u53e5\u5c06\u6b63\u5e38\u5de5\u4f5c\u5e76\u5220\u9664\u8868\u4e2d\u7684\u6240\u6709\u884c\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">DELETE<\/span> <span class=\"k\">FROM<\/span> <span class=\"n\">zero_column<\/span> <span class=\"p\">;<\/span>\r\n<span class=\"k\">DELETE<\/span> <span class=\"mi\">6<\/span>\r\n<\/code><\/pre>\n<p>\u5047\u8bbe\u6709\u4e00\u4e2a\u62e5\u67096\u884c\u76840\u5217\uff0c\u80fd\u591f\u5220\u9664\u7b2c3\u884c\u5417\uff1f<\/p>\n<p>\u4f60\u5728\u8bf4\u4ec0\u4e48\uff1f\u8fd9\u4e2a\u6848\u5b50\uff0c\u6211\u8bd5\u7740\u7528\u6700\u540e\u7684\u529e\u6cd5\u5199\u4e86\u4e00\u4e0b\u3002<\/p>\n<details>\u5220\u9664\u7b2c0\u5217\u7684\u7b2c3\u884cDELETE\u4ecezero_column\u4e2d\u9009\u62e9ctid;<br \/>\nctid<br \/>\n&#8212;&#8212;&#8211;<br \/>\n(0,7)<br \/>\n(0,8)<br \/>\n(0,9) &lt;&#8211; \u60f3\u8981\u5220\u9664\u8fd9\u4e2a<br \/>\n(0,10)<br \/>\n(0,11)<br \/>\n(0,12)<br \/>\n(6 \u884c)<\/p>\n<p>DELETE FROM zero_column WHERE ctid = &#8216;(0,9)&#8217;;<br \/>\nDELETE 1<\/p>\n<p>\u6211\u60f3\u5230\u7684\u5176\u4ed6\u65b9\u6cd5\u90fd\u5931\u8d25\u4e86\u3002<\/p>\n<\/details>\n<h2>\u66f4\u65b0\u662f\u5426\u652f\u6301\u7b2c0\u5217\uff1f<\/h2>\n<p>\u771f\u7684\u641e\u4e0d\u61c2\u3002\u7a46\u5229\u3002<\/p>\n<h2>\u603b\u7ed3<\/h2>\n<pre class=\"post-pre\"><code><span class=\"k\">SELECT<\/span> <span class=\"k\">FROM<\/span> <span class=\"err\">\u30aa\u30c1<\/span><span class=\"p\">;<\/span>\r\n<span class=\"c1\">--<\/span>\r\n<span class=\"p\">(<\/span><span class=\"mi\">1<\/span> <span class=\"k\">rows<\/span><span class=\"p\">)<\/span>\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u9996\u5148 \u5bf9\u4e0d\u8d77\uff0c\u8fd9\u4e0d\u662f\u4e00\u7bc7\u4ece\u96f6\u5f00\u59cb\u5b66\u4e60PostgreSQL\u7684\u5165\u95e8\u6587\u7ae0\u3002 \u5f88\u62b1\u6b49\u6807\u9898\u53ef\u80fd\u8bef\u5bfc\u4e86\u3002 \u6211\u5c06\u5728Postg [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-41371","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>\u4ee5&quot;0()&quot;\u4e3a\u8d77\u59cb\u7684PostgreSQL - Blog - Silicon Cloud<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/zh\/blog\/\u4ee50\u4e3a\u8d77\u59cb\u7684postgresql\/\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" 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