Question

我有两个表a和a_history，如何确定何时更改a，删除或添加或修改了一个列，然后在{{1}中更改它}}

a_history记录了

a_history

例如，您将“code”varchar添加到a = (id,name,status) a_history = (id,name,status,id_history,operation,date_op,...)，然后a必须具有“code”varchar

如果您更改为a_history中的“代码”int，则a必须包含“代码”a_history而不是int

Answer 1

这是我用来比较两个MySQL数据库结构的脚本：

<?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>";
            }
        }
    }
}
?>

获得两个表之间的差异？

1 个答案: