yiisoft/yii2 · error · yii\base\NotSupportedException

MySQL < 8.0.16 does not support check constraints.

Error message

MySQL < 8.0.16 does not support check constraints.

What it means

yii\db\mysql\Schema::loadTableChecks() introspects CHECK constraints from INFORMATION_SCHEMA, but MySQL only started storing them in version 8.0.16 - older versions parse and silently ignore CHECK clauses. On non-MariaDB servers below 8.0.16 the method throws NotSupportedException. MariaDB is exempted because its version string contains 'MariaDb' and it has long supported check constraints.

Source

Thrown at framework/db/mysql/Schema.php:216

    /**
     * {@inheritdoc}
     */
    protected function loadTableUniques($tableName)
    {
        return $this->loadTableConstraints($tableName, 'uniques');
    }

    /**
     * {@inheritdoc}
     */
    protected function loadTableChecks($tableName)
    {
        $version = $this->db->getServerVersion();

        // check version MySQL >= 8.0.16
        if (\stripos($version, 'MariaDb') === false && \version_compare($version, '8.0.16', '<')) {
            throw new NotSupportedException('MySQL < 8.0.16 does not support check constraints.');
        }

        $checks = [];

        $sql = <<<SQL
        SELECT cc.CONSTRAINT_NAME as constraint_name, cc.CHECK_CLAUSE as check_clause
        FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS tc
        JOIN INFORMATION_SCHEMA.CHECK_CONSTRAINTS cc
        ON tc.CONSTRAINT_NAME = cc.CONSTRAINT_NAME
        WHERE tc.TABLE_NAME = :tableName AND tc.CONSTRAINT_TYPE = 'CHECK';
        SQL;

        $resolvedName = $this->resolveTableName($tableName);
        $tableRows = $this->db->createCommand($sql, [':tableName' => $resolvedName->name])->queryAll();

        if ($tableRows === []) {
            return $checks;
        }

View on GitHub (pinned to 66f00d18a2)

Solutions

1. Upgrade the MySQL server to 8.0.16 or newer.
2. Gate the call: skip getTableChecks() when $db->getServerVersion() is below 8.0.16 and the driver is mysql.
3. Catch NotSupportedException in cross-version introspection code and treat checks as an empty list.
4. On MariaDB no action is needed - the version guard already excludes it.

Example fix

// before
$checks = $db->getTableChecks('order');

// after
$version = $db->getServerVersion();
$isMySql = stripos($version, 'MariaDb') === false;
$checks = ($isMySql && version_compare($version, '8.0.16', '<'))
    ? []
    : $db->getTableChecks('order');

function mysqlSupportsCheckIntrospection(\yii\db\Connection $db): bool
{
    $version = $db->getServerVersion();
    return stripos($version, 'MariaDb') !== false
        || version_compare($version, '8.0.16', '>=');
}

$checks = mysqlSupportsCheckIntrospection($db) ? $db->getTableChecks('order') : [];

try {
    $checks = $db->getTableChecks('order');
} catch (\yii\db\NotSupportedException $e) {
    $checks = []; // MySQL < 8.0.16: CHECK constraints are parsed but not stored
}

When it happens

Trigger: Calling $db->getTableChecks('tbl') on MySQL 5.6/5.7/8.0.0-8.0.15, directly or from generic code that iterates all constraint types (Gii model generation, schema dump tools, debug panels).

Common situations: Developing against MySQL 8 and deploying to an older production server; CI images older than production; mixed fleets where some hosts run 5.7; tools assuming uniform introspection support.

Related errors

• Table not found: $tableName
• There is no sequence associated with table '$tableName'.
• Unable to find column '$column' in table '$table'.
• MySQL does not support default value constraints.
• DbDependency::sql must be set.

AI-assisted analysis of yiisoft/yii2@66f00d18a2 (2026-08-17). Data as JSON: /api/errors/13b6244d23f80c16. Report an issue: GitHub.