两个不同远程机器上的两个MySQL数据库之间的区别（mysqldiff使用说明） [英] Difference between two MySQL databases which are on two different remote machines (mysqldiff usage clarification)

问题描述

我只想了解两个不同远程机器上的两个mysql数据库之间的区别，我知道 mysqldiff 可以用于这种目的，我使用它。但问题是，我可以找到我的（或本地）机器上的数据库与远程数据库之间的区别，但是，如果两个数据库，我们想要找到的差异是在两个不同的远程机器上，这是不可能的（或我不知道如何使用它）。

I just want to find out the difference between two mysql databases which are on two different remote machines, I know mysqldiff can be used for this kind of purpose, and I am using it. But the problem is, I can find the difference between the db on my (or local) machine with a remote database, But, If both databases , for which we want to find the difference are on two different remote machines, it is not possible (or I dont know how to use it). can anybody tell me how to achieve this.

提前感谢

推荐答案

p>这里是我用来比较两个不同的MySQL数据库的脚本。要比较两个远程数据库，您只需要将 $ db1_host 从 localhost 更改为其他远程的IP地址

Here's a script I use to compare two different MySQL databases. To compare two remote databases you'll just need to change $db1_host from localhost to the IP address of the other remote server.

<?php
//------------------------------------------------------------------------------
// Define the variables we'll be using.
//------------------------------------------------------------------------------
$db1_con = NULL;
$db1_constraints = array();
$db1_dbname = 'db1';
$db1_host = 'localhost';
$db1_password = 'password1';
$db1_tables = array();
$db1_username = 'username1';

$db2_con = NULL;
$db2_constraints = array();
$db2_dbname = 'db2';
$db2_host = '123.123.123.123';
$db2_password = 'password2';
$db2_tables = array();
$db2_username = 'username2';

//------------------------------------------------------------------------------
// Connect to the databases.
//------------------------------------------------------------------------------
try{
    $db1_con = new PDO("mysql:host=$db1_host;dbname=information_schema", $db1_username, $db1_password);
    $db1_con->setAttribute(PDO::ATTR_EMULATE_PREPARES, FALSE); // Try to use the driver's native prepared statements.
    $db1_con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // Let's use exceptions so we can try/catch errors.
}catch(PDOException $e){
    echo "<p>Connection failed for $db1_host: " . $e->getMessage() . '</p>';
    exit;
}

try{
    $db2_con = new PDO("mysql:host=$db2_host;dbname=information_schema", $db2_username, $db2_password);
    $db2_con->setAttribute(PDO::ATTR_EMULATE_PREPARES, FALSE); // Try to use the driver's native prepared statements.
    $db2_con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); // Let's use exceptions so we can try/catch errors.
}catch(PDOException $e){
    echo "<p>Connection failed for $db2_host: " . $e->getMessage() . '</p>';
    exit;
}

if (NULL !== $db1_con && NULL !== $db2_con){
    echo "<h2>Column Analysis</h2>";
    $sql = 'SELECT * FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = ? ORDER BY TABLE_NAME, ORDINAL_POSITION';
    $statement1 = $db1_con->prepare($sql);
    $statement1->bindValue(1, $db1_dbname);

    $statement2 = $db2_con->prepare($sql);
    $statement2->bindValue(1, $db2_dbname);

    if (TRUE === $statement1->execute()){
        while ($row = $statement1->fetch(PDO::FETCH_ASSOC)){
            $db1_tables[$row['TABLE_NAME']][$row['COLUMN_NAME']] = array();
            foreach ($row AS $key => $value){
                $db1_tables[$row['TABLE_NAME']][$row['COLUMN_NAME']][$key] = $value;
            }
        }
    }

    if (TRUE === $statement2->execute()){
        while ($row = $statement2->fetch(PDO::FETCH_ASSOC)){
            $db2_tables[$row['TABLE_NAME']][$row['COLUMN_NAME']] = array();
            foreach ($row AS $key => $value){
                $db2_tables[$row['TABLE_NAME']][$row['COLUMN_NAME']][$key] = $value;
            }
        }
    }

    foreach ($db1_tables AS $table => $info){
        if (!isset($db2_tables[$table])){
            echo "<p>Table <strong>$table</strong> does not exist in the SECOND database!</p>";
        }else{
            foreach ($info AS $column => $data){
                if (!isset($db2_tables[$table][$column])){
                    echo "<p>Column <strong>$column</strong> does not exist in table <strong>$table</strong> in the SECOND database!</p>";
                }else{
                    if (count($data)){
                        foreach ($data AS $key => $value){
                            if ($db1_tables[$table][$column][$key] !== $db2_tables[$table][$column][$key]){
                                echo "<p>Column <strong>$column</strong> in table <strong>$table</strong> has differing characteristics for <strong>$key</strong> (". $db1_tables[$table][$column][$key] ." vs. ". $db2_tables[$table][$column][$key] .")</p>";
                            }
                        }
                    }
                }
            }
        }
    }

    foreach ($db2_tables AS $table => $info){
        if (!isset($db1_tables[$table])){
            echo "<p>Table <strong>$table</strong> does not exist in the FIRST database!</p>";
        }else{
            foreach ($info AS $column => $data){
                if (!isset($db1_tables[$table][$column])){
                    echo "<p>Column <strong>$column</strong> does not exist in table <strong>$table</strong> in the FIRST database!</p>";
                }else{
                    if (count($data)){
                        foreach ($data AS $key => $value){
                            if ($db2_tables[$table][$column][$key] !== $db1_tables[$table][$column][$key]){
                                echo "<p>Column <strong>$column</strong> in table <strong>$table</strong> has differing characteristics for <strong>$key</strong> (". $db2_tables[$table][$column][$key] ." vs. ". $db1_tables[$table][$column][$key] .")</p>";
                            }
                        }
                    }
                }
            }
        }
    }
    echo "<h2>Constraint Analysis</h2>";

    $sql = 'SELECT * FROM information_schema.KEY_COLUMN_USAGE WHERE TABLE_SCHEMA = ? ORDER BY TABLE_NAME, ORDINAL_POSITION';
    $statement1 = $db1_con->prepare($sql);
    $statement1->bindValue(1, $db1_dbname);

    $statement2 = $db2_con->prepare($sql);
    $statement2->bindValue(1, $db2_dbname);

    if (TRUE === $statement1->execute()){
        while ($row = $statement1->fetch(PDO::FETCH_ASSOC)){
            foreach ($row AS $key => $value){
                $db1_constraints[$row['TABLE_NAME']][$row['COLUMN_NAME']][$key] = $value;
            }
        }
    }

    if (TRUE === $statement2->execute()){
        while ($row = $statement2->fetch(PDO::FETCH_ASSOC)){
            foreach ($row AS $key => $value){
                $db2_constraints[$row['TABLE_NAME']][$row['COLUMN_NAME']][$key] = $value;
            }
        }
    }

    foreach ($db1_constraints AS $table => $info){
        foreach ($info AS $column => $data){
            if (isset($db2_constraints[$table][$column])){
                if (count($data)){
                    foreach ($data AS $key => $value){
                        if ('CONSTRAINT_NAME' !== $key && $db1_constraints[$table][$column][$key] !== $db2_constraints[$table][$column][$key]){
                            echo "<p>Column <strong>$column</strong> in table <strong>$table</strong> has differing characteristics for <strong>$key</strong> (". $db1_constraints[$table][$column][$key] ." vs. ". $db2_constraints[$table][$column][$key] .")</p>";
                        }
                    }
                }
            }else{
                echo "<p>Column <strong>$column</strong> in table <strong>$table</strong> is missing a constraint in the SECOND database!</p>";
            }
        }
    }

    foreach ($db2_constraints AS $table => $info){
        foreach ($info AS $column => $data){
            if (isset($db1_constraints[$table][$column])){
                if (count($data)){
                    foreach ($data AS $key => $value){
                        if ('CONSTRAINT_NAME' !== $key && $db2_constraints[$table][$column][$key] !== $db1_constraints[$table][$column][$key]){
                            echo "<p>Column <strong>$column</strong> in table <strong>$table</strong> has differing characteristics for <strong>$key</strong> (". $db2_constraints[$table][$column][$key] ." vs. ". $db1_constraints[$table][$column][$key] .")</p>";
                        }
                    }
                }
            }else{
                echo "<p>Column <strong>$column</strong> in table <strong>$table</strong> is missing a constraint in the FIRST database!</p>";
            }
        }
    }
}
?>

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