Yiisoft\Db\Mysql\Schema::findConstraints()

Complexity

Conditions	9
Paths	43

Size

Total Lines	75
Code Lines	52

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	15
CRAP Score	19.125

Importance

Changes	2
Bugs	0	Features	0

<?php
    protected function findConstraints(TableSchemaInterface $table): void
    {
        $sql = <<<SQL
        SELECT
            `kcu`.`CONSTRAINT_NAME` AS `constraint_name`,
            `kcu`.`COLUMN_NAME` AS `column_name`,
            `kcu`.`REFERENCED_TABLE_NAME` AS `referenced_table_name`,
            `kcu`.`REFERENCED_COLUMN_NAME` AS `referenced_column_name`
        FROM `information_schema`.`REFERENTIAL_CONSTRAINTS` AS `rc`
        JOIN `information_schema`.`KEY_COLUMN_USAGE` AS `kcu` ON
            (
                `kcu`.`CONSTRAINT_CATALOG` = `rc`.`CONSTRAINT_CATALOG` OR
                (
                    `kcu`.`CONSTRAINT_CATALOG` IS NULL AND
                    `rc`.`CONSTRAINT_CATALOG` IS NULL
                )
            ) AND
            `kcu`.`CONSTRAINT_SCHEMA` = `rc`.`CONSTRAINT_SCHEMA` AND
            `kcu`.`CONSTRAINT_NAME` = `rc`.`CONSTRAINT_NAME` AND
            `kcu`.`TABLE_SCHEMA` = `rc`.`CONSTRAINT_SCHEMA` AND
            `kcu`.`TABLE_NAME` = `rc`.`TABLE_NAME`
        WHERE
            `rc`.`CONSTRAINT_SCHEMA` = COALESCE(:schemaName, DATABASE()) AND
            `rc`.`TABLE_NAME` = :tableName
        SQL;

        try {
            $rows = $this->db->createCommand($sql, [
                ':schemaName' => $table->getSchemaName(),
                ':tableName' => $table->getName(),
            ])->queryAll();

            $constraints = [];

            /**  @psalm-var RowConstraint $row */
            foreach ($rows as $row) {
                $constraints[$row['constraint_name']]['referenced_table_name'] = $row['referenced_table_name'];
                $constraints[$row['constraint_name']]['columns'][$row['column_name']] = $row['referenced_column_name'];
            }

            $table->foreignKeys([]);

            /**
             * @var array{referenced_table_name: string, columns: array} $constraint
             */
            foreach ($constraints as $name => $constraint) {
                $table->foreignKey($name, array_merge(
                    [$constraint['referenced_table_name']],
                    $constraint['columns']
                ));
            }
        } catch (Exception $e) {
            $previous = $e->getPrevious();

            if ($previous === null || !str_contains($previous->getMessage(), 'SQLSTATE[42S02')) {
                throw $e;
            }

            // table does not exist, try to determine the foreign keys using the table creation sql
            $sql = $this->getCreateTableSql($table);
            $regexp = '/FOREIGN KEY\s+\(([^)]+)\)\s+REFERENCES\s+([^(^\s]+)\s*\(([^)]+)\)/mi';

            if (preg_match_all($regexp, $sql, $matches, PREG_SET_ORDER)) {
                foreach ($matches as $match) {
                    $fks = array_map('trim', explode(',', str_replace('`', '', $match[1])));
                    $pks = array_map('trim', explode(',', str_replace('`', '', $match[3])));
                    $constraint = [str_replace('`', '', $match[2])];

                    foreach ($fks as $k => $name) {
                        $constraint[$name] = $pks[$k];
                    }

                    $table->foreignKey(md5(serialize($constraint)), $constraint);
                }
                $table->foreignKeys(array_values($table->getForeignKeys()));
            }