<?php

$servername = "localhost";

$username = "root";

$password = "root";

$dbname = "abc";

// 初始化数据库连接

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接是否成功

if ($conn->connect_error) {

    die("Connection failed: " . $conn->connect_error);

}

// 要替换的字符串

$search = '张三';

$replace = '李四';

// 获取所有表的名称

$tables_result = $conn->query("SHOW TABLES");

$tables = array();

while ($row = $tables_result->fetch_row()) {

    $tables[] = $row[0];

}

// 遍历所有的表，依次替换它们的内容

foreach ($tables as $table) {

    $columns_result = $conn->query("SHOW COLUMNS FROM ".$table);

    $columns = array();

    while ($row = $columns_result->fetch_assoc()) {

        $columns[] = $row['Field'];

    }

    foreach ($columns as $column) {

        $conn->query("UPDATE ".$table." SET $column = REPLACE(".$column.", '".$search."', '".$replace."')");

    }

    echo "表".$table." 替换成功!<br>";

}

// 关闭数据库连接

$conn->close();

?>