即使下面的建议不应该被认为是最终的解决方案，你也可以通过这样做来实现目标:

SET SESSION group_concat_max_len = 1000000;
SET @search = 'Text_To_Search';

DROP table IF EXISTS table1;
CREATE TEMPORARY TABLE table1 AS 
(SELECT 
    CONCAT('SELECT \'',TABLE_NAME,'\' as \'table_name\',\'',COLUMN_NAME,'\' as \'column_name\',CONVERT(count(*),char) as \'matches\' FROM `',
    TABLE_NAME,'` where `',COLUMN_NAME,'` like \'%',@search,'%\' UNION ') as 'query'
FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'db_name' limit 1000000);

set @query = (SELECT GROUP_CONCAT(t1.`query` SEPARATOR '') as 'final_query' from table1 t1 limit 1);
set @query = (SELECT SUBSTRING(@query, 1, length(@query) - 7));

PREPARE stmt FROM @query;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

请记住:

选项:group_concat_max_len和limit 1000000并不总是必需的，这将取决于您的服务器/IDE配置。以防我加进去。 执行此命令后，您将得到一个3列响应:[table_name]， [column_name]， [matches] 列'matches'是给定表/列中出现的次数。 这个查询非常快。

免责声明:它只对个人使用有用，换句话说，请不要在生产系统中使用它，因为考虑到搜索参数与其他字符串连接，它对SQL注入攻击很敏感。 如果你想创建一个prod. ready函数，那么你需要创建一个带有LOOP的存储过程。

使用MySQL Workbench可以很容易地选择几个表，并在所有这些数据库表中搜索文本;-)

这是我的解决方案

DROP PROCEDURE IF EXISTS findAll;
CREATE PROCEDURE `findAll`( IN `tableName` VARCHAR( 28 ) , IN `search` TEXT )
BEGIN
       DECLARE finished INT DEFAULT FALSE ;
       DECLARE columnName VARCHAR ( 28 ) ;
       DECLARE stmtFields TEXT ;
       DECLARE columnNames CURSOR FOR
              SELECT DISTINCT `COLUMN_NAME` FROM `information_schema`.`COLUMNS`
              WHERE `TABLE_NAME` = tableName ORDER BY `ORDINAL_POSITION` ;
       DECLARE CONTINUE HANDLER FOR NOT FOUND SET finished = TRUE;
       SET stmtFields = '' ;
       OPEN columnNames ;
       readColumns: LOOP
              FETCH columnNames INTO columnName ;
              IF finished THEN
                     LEAVE readColumns ;
              END IF;
              SET stmtFields = CONCAT(
                     stmtFields , IF ( LENGTH( stmtFields ) > 0 , ' OR' , ''  ) ,
                     ' `', tableName ,'`.`' , columnName , '` REGEXP "' , search , '"'
              ) ;
       END LOOP;
       SET @stmtQuery := CONCAT ( 'SELECT * FROM `' , tableName , '` WHERE ' , stmtFields ) ;
       PREPARE stmt FROM @stmtQuery ;
       EXECUTE stmt ;
       CLOSE columnNames ;
END;

我要用这个。你只需要改变变量

$query ="SELECT `column_name` FROM `information_schema`.`columns` WHERE `table_schema`='" . $_SESSION['db'] . "' AND `table_name`='" . $table . "' ";
$stmt = $dbh->prepare($query);
$stmt->execute(); 
$columns = $stmt->fetchAll(PDO::FETCH_ASSOC);       

$query="SELECT name FROM `" . $database . "`.`" . $table . "` WHERE ( ";
foreach ( $columns as $column ) {
    $query .=" CONVERT( `" . $column['column_name'] . "` USING utf8 ) LIKE '%" . $search . "%' OR ";
}
$query = substr($query, 0, -3);
$query .= ")";

echo $query . "<br>";
$stmt=$dbh->prepare($query);
$stmt->execute();
$results = $stmt->fetchAll(PDO::FETCH_ASSOC);
echo "<pre>";
print_r ($results );
echo "</pre>";

PHP函数:

function searchAllDB($search){
    global $mysqli;
    
    $out = Array();
    
    $sql = "show tables";
    $rs = $mysqli->query($sql);
    if($rs->num_rows > 0){
        while($r = $rs->fetch_array()){
            $table = $r[0];
            $sql_search = "select * from `".$table."` where ";
            $sql_search_fields = Array();
            $sql2 = "SHOW COLUMNS FROM `".$table."`";
            $rs2 = $mysqli->query($sql2);
            if($rs2->num_rows > 0){
                while($r2 = $rs2->fetch_array()){
                    $column = $r2[0];
                    $sql_search_fields[] = "`".$column."` like('%".$mysqli->real_escape_string($search)."%')";
                }
                $rs2->close();
            }
            $sql_search .= implode(" OR ", $sql_search_fields);
            $rs3 = $mysqli->query($sql_search);
            $out[$table] = $rs3->num_rows."\n";
            if($rs3->num_rows > 0){
                $rs3->close();
            }
        }
        $rs->close();
    }
    
    return $out;
}

print_r(searchAllDB("search string"));

您可以查看information_schema模式。它包含所有表和表中所有字段的列表。然后，您可以使用从该表中获得的信息运行查询。

涉及的表包括SCHEMATA、tables和COLUMNS。有一些外键，这样您就可以在模式中准确地构建表的创建方式。