我需要向给定数据库中的一组表添加主键。我不知道会有多少张桌子或它们的具体名称是什么。它们都属于数据表_##，其中 ## 将根据我的脚本运行的任何地方而有所不同。
要添加主键，我使用这个查询：
alter table datatable_??
add column ID int auto_increment not null first,
add primary key (ID);
所以，我需要在数据库中的每个表上运行它。似乎我可以在 PHP 脚本或其他东西中做到这一点，但他们只是在 sql 脚本中做到这一点的更简单的方法吗？
【问题讨论】：
标签： mysql database primary-key
如果你想完全编写脚本，你可以这样做：
SELECT CONCAT('ALTER TABLE ',
table_schema,
'.',
table_name,
' ADD COLUMN id INT AUTO_INCREMENT NOT NULL PRIMARY KEY FIRST;') AS ddl
INTO OUTFILE '/tmp/alter_table.sql'
FROM information_schema.tables
WHERE table_schema = 'db_name'
AND table_type = 'base table';
\. /tmp/alter_table.sql
【讨论】：
select concat('alter table ',table_name,' add column ID int auto_increment not null primary key first;')
from information_schema.tables
where table_schema = 'db_name' and table_type = 'base table';
获得输出后，复制并粘贴并运行它们。
【讨论】：
SELECT INTO OUTFILE 将 DDL 命令写入脚本，然后获取该脚本以执行命令来避免复制和粘贴步骤。
您可以执行以下操作来更改列。这使用游标来遍历表名并且不使用文本文件或任何东西。您必须将其创建为存储过程，因为游标不能在外部使用。
DELIMITER $$
USE `db_name`$$
DROP PROCEDURE IF EXISTS `alter_test_1`$$
CREATE DEFINER=`db_name`@`10.%` PROCEDURE `alter_test_1`()
BEGIN
DECLARE v_finished INTEGER DEFAULT 0;
DECLARE v_table VARCHAR(100) DEFAULT "";
DECLARE stmt VARCHAR(500) DEFAULT "";
DECLARE column_cursor CURSOR FOR
SELECT * FROM `information_schema`.`tables` WHERE table_schema = 'db_name' AND table_name LIKE 'mytables_%';
DECLARE CONTINUE HANDLER
FOR NOT FOUND SET v_finished = 1;
OPEN column_cursor;
alter_tables: LOOP
FETCH column_cursor INTO v_table;
IF v_finished = 1 THEN
LEAVE alter_tables;
END IF;
SET @prepstmt = CONCAT('ALTER TABLE adtracker','.',v_table,' ADD COLUMN id INT AUTO_INCREMENT NOT NULL;');
PREPARE stmt FROM @prepstmt;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END LOOP alter_tables;
CLOSE column_cursor;
END$$
DELIMITER ;
【讨论】：
<?php
// ====Variable ============
$sServerHost="localhost";
$sLocalHost="localhost";
$sServerUser="root";
$sLocalUser="root";
$sServerPassword="";
$sLocalPassword="";
$sLocalDatabaseName="test";
$sServerDatabaseName="test";
$Add_columnname="session_language";
// ====db connection============
$conn = @mysql_connect($sServerUser,$sServerUser,$sServerPassword);
if(!$conn) {
$conn = mysql_connect($sLocalHost,$sLocalUser,$sLocalPassword);
}
$db=mysql_select_db($sServerDatabaseName);
if(!$db){
$db=mysql_select_db($sLocalDatabaseName);
}
// =====basic function liberary============
class Model
{
function find_query_all($pred = '', $params = array(), $select = '*')
{
global $db;
$sql = $pred;
$rows = array();
$rows =$this->getAll($sql, $params);
$this->_check_error($rows);
if(count($rows)>0){
$this->_row_count=count($rows);
}
else
$this->_row_count=0;
return $rows;
}
//====== fetch rows from db and return array of row object
function getAll($sqlQuery='',$params= array())
{
$msg="";
$this->_sqlQuery="";
$sQuery=$this->MakeSQLQuery($sqlQuery,$params);
$this->_sqlQuery=$sQuery;
$res=mysql_query($sQuery) or die(mysql_error());
$results = array();
if(mysql_num_rows($res)>0){
while ($row = mysql_fetch_object($res)) {
$results[] = $row;
}
}
return $results;
}
function MakeSQLQuery($str='',$params= array())
{
foreach($params as $k=>$v){
$params[$k]=$this->_quote($params[$k]);
}
$str=$this->replace_different("?",$params,$str);
return $str;
}
function replace_different($search,$replace,$string) {
$occs = substr_count($string,$search);
$last = 0;
$cur = 0;
$data = '';
for ($i=0;$i<$occs;$i++) {
$find = strpos($string,$search,$last);
$data .= substr($string,$last,$find-$last).$replace[$cur];
$last = $find+strlen($search);
if (++$cur == count($replace)) {
$cur = 0;
}
}
return $data.substr($string,$last);
}
// check for a database error
function _check_error($obj, $msg = 'Database Error')
{
if (!$this->isError($obj))
{
$this->raise_error($msg . ': ' .$obj->getMessage(). mysql_error());
}
return ;
}
function isError($value)
{
if(isset($value))
return true;
else
return false;
}
}
// main operation from here
//====define object of class========
$tbl_col = new Model;
$sqlquery_col="SELECT table_name FROM information_schema.tables where table_schema='".$sLocalDatabaseName."'";
$res_tab_col=$tbl_col->find_query_all($sqlquery_col);
foreach($res_tab_col as $r=>$v){
$res=mysql_query("SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = '".$sLocalDatabaseName."' AND TABLE_NAME ='".$v->table_name."' and COLUMN_NAME!='".$Add_columnname."' ORDER BY ORDINAL_POSITION DESC LIMIT 1");
if(mysql_num_rows($res)>0){
while ($row = mysql_fetch_object($res)) {
$last_column= $row->COLUMN_NAME;
$alter_query="ALTER TABLE `".$v->table_name."` ADD `".$Add_columnname."` INT NOT NULL DEFAULT '1' AFTER `".$last_column."` ";
mysql_query($alter_query);
}
}
}
?>
【讨论】：