Source of file SQL.php

<?php declare(strict_types=1);

/**

 * Query

 *

 * SQL Query Builder / Database Abstraction Layer

 *

 * PHP version 7.1

 *

 * @package     Query

 * @author      Timothy J. Warren <tim@timshomepage.net>

 * @copyright   2012 - 2018 Timothy J. Warren

 * @license     http://www.opensource.org/licenses/mit-license.html  MIT License

 * @link        https://git.timshomepage.net/aviat4ion/Query

 */

namespace Query\Drivers\Mysql;

use Query\Drivers\AbstractSQL;

/**

 * MySQL specific SQL

 */

class SQL extends AbstractSQL {

	/**

	 * Limit clause

	 *

	 * @param string $sql

	 * @param int $limit

	 * @param int|boolean $offset

	 * @return string

	 */

	public function limit(string $sql, int $limit, $offset=FALSE): string

	{

		if ( ! is_numeric($offset))

		{

			return $sql." LIMIT {$limit}";

		}

		return $sql." LIMIT {$offset}, {$limit}";

	}

	/**

	 * Get the query plan for the sql query

	 *

	 * @param string $sql

	 * @return string

	 */

	public function explain(string $sql): string

	{

		return "EXPLAIN EXTENDED {$sql}";

	}

	/**

	 * Random ordering keyword

	 *

	 * @return string

	 */

	public function random(): string

	{

		return ' RAND() DESC';

	}

	/**

	 * Returns sql to list other databases

	 *

	 * @return string

	 */

	public function dbList(): string

	{

		return <<<SQL

			SHOW DATABASES WHERE `Database` NOT IN ('information_schema','mysql')

SQL;

	}

	/**

	 * Returns sql to list tables

	 *

	 * @param string $database

	 * @return string

	 */

	public function tableList($database=''): string

	{

		// @codeCoverageIgnoreStart

		if ( ! empty($database))

		{

			return "SHOW TABLES FROM `{$database}`";

		}

		// @codeCoverageIgnoreEnd

		return 'SHOW TABLES';

	}

	/**

	 * Overridden in MySQL class

	 *

	 * @return string

	 */

	public function systemTableList(): string

	{

		return <<<SQL

			SELECT `TABLE_NAME` FROM `information_schema`.`TABLES`

			WHERE `TABLE_SCHEMA`='information_schema'

SQL;

	}

	/**

	 * Returns sql to list views

	 *

	 * @return string

	 */

	public function viewList(): string

	{

		return 'SELECT `table_name` FROM `information_schema`.`views`';

	}

	/**

	 * Returns sql to list triggers

	 *

	 * @return string

	 */

	public function triggerList(): string

	{

		return 'SHOW TRIGGERS';

	}

	/**

	 * Return sql to list functions

	 *

	 * @return string

	 */

	public function functionList(): string

	{

		return 'SHOW FUNCTION STATUS';

	}

	/**

	 * Return sql to list stored procedures

	 *

	 * @return string

	 */

	public function procedureList(): string

	{

		return 'SHOW PROCEDURE STATUS';

	}

	/**

	 * Return sql to list sequences

	 *

	 * @return string

	 */

	public function sequenceList(): ?string

	{

		return NULL;

	}

	/**

	 * SQL to show list of field types

	 *

	 * @return string

	 */

	public function typeList(): string

	{

		return 'SELECT DISTINCT `DATA_TYPE` FROM `information_schema`.`COLUMNS`';

	}

	/**

	 * SQL to show infromation about columns in a table

	 *

	 * @param string $table

	 * @return string

	 */

	public function columnList(string $table): string

	{

		return "SHOW FULL COLUMNS FROM {$table}";

	}

	/**

	 * Get the list of foreign keys for the current

	 * table

	 *

	 * @param string $table

	 * @return string

	 */

	public function fkList(string $table): string

	{

		return <<<SQL

			SELECT DISTINCT 

				`kcu`.`COLUMN_NAME` as `child_column`,

				`kcu`.`REFERENCED_TABLE_NAME` as `parent_table`,

				`kcu`.`REFERENCED_COLUMN_NAME` as `parent_column`,

				`rc`.`UPDATE_RULE` AS `update`,

				`rc`.`DELETE_RULE` AS `delete`

			FROM `INFORMATION_SCHEMA`.`TABLE_CONSTRAINTS` `tc`

			INNER JOIN `INFORMATION_SCHEMA`.`KEY_COLUMN_USAGE` `kcu`

				ON `kcu`.`CONSTRAINT_NAME`=`tc`.`CONSTRAINT_NAME`

			INNER JOIN `INFORMATION_SCHEMA`.`REFERENTIAL_CONSTRAINTS` `rc`

				ON `rc`.`CONSTRAINT_NAME`=`tc`.`CONSTRAINT_NAME`

			WHERE `tc`.`CONSTRAINT_TYPE`='FOREIGN KEY'

			AND `tc`.`TABLE_NAME`='{$table}'

SQL;

	}

	/**

	 * Get the list of indexes for the current table

	 *

	 * @param string $table

	 * @return string

	 */

	public function indexList(string $table): string

	{

		return "SHOW INDEX IN {$table}";

	}

}