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@Likeyn
Last active February 13, 2020 11:01
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Check foreign keys integrity
-- Check foreign keys integrity
-- @link http://stackoverflow.com/a/12085689/1752536
DELIMITER $$
DROP PROCEDURE IF EXISTS ANALYZE_INVALID_FOREIGN_KEYS$$
CREATE
PROCEDURE `ANALYZE_INVALID_FOREIGN_KEYS`(
checked_database_name VARCHAR(64),
checked_table_name VARCHAR(64),
temporary_result_table ENUM('Y', 'N'))
LANGUAGE SQL
NOT DETERMINISTIC
READS SQL DATA
BEGIN
DECLARE TABLE_SCHEMA_VAR VARCHAR(64);
DECLARE TABLE_NAME_VAR VARCHAR(64);
DECLARE COLUMN_NAME_VAR VARCHAR(64);
DECLARE CONSTRAINT_NAME_VAR VARCHAR(64);
DECLARE REFERENCED_TABLE_SCHEMA_VAR VARCHAR(64);
DECLARE REFERENCED_TABLE_NAME_VAR VARCHAR(64);
DECLARE REFERENCED_COLUMN_NAME_VAR VARCHAR(64);
DECLARE KEYS_SQL_VAR VARCHAR(1024);
DECLARE done INT DEFAULT 0;
DECLARE foreign_key_cursor CURSOR FOR
SELECT
`TABLE_SCHEMA`,
`TABLE_NAME`,
`COLUMN_NAME`,
`CONSTRAINT_NAME`,
`REFERENCED_TABLE_SCHEMA`,
`REFERENCED_TABLE_NAME`,
`REFERENCED_COLUMN_NAME`
FROM
information_schema.KEY_COLUMN_USAGE
WHERE
`CONSTRAINT_SCHEMA` LIKE checked_database_name AND
`TABLE_NAME` LIKE checked_table_name AND
`REFERENCED_TABLE_SCHEMA` IS NOT NULL;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
IF temporary_result_table = 'N' THEN
DROP TEMPORARY TABLE IF EXISTS INVALID_FOREIGN_KEYS;
DROP TABLE IF EXISTS INVALID_FOREIGN_KEYS;
CREATE TABLE INVALID_FOREIGN_KEYS(
`TABLE_SCHEMA` VARCHAR(64),
`TABLE_NAME` VARCHAR(64),
`COLUMN_NAME` VARCHAR(64),
`CONSTRAINT_NAME` VARCHAR(64),
`REFERENCED_TABLE_SCHEMA` VARCHAR(64),
`REFERENCED_TABLE_NAME` VARCHAR(64),
`REFERENCED_COLUMN_NAME` VARCHAR(64),
`INVALID_KEY_COUNT` INT,
`INVALID_KEY_SQL` VARCHAR(1024),
`INVALID_KEY_DELETE_SQL` VARCHAR(1024)
);
ELSEIF temporary_result_table = 'Y' THEN
DROP TEMPORARY TABLE IF EXISTS INVALID_FOREIGN_KEYS;
DROP TABLE IF EXISTS INVALID_FOREIGN_KEYS;
CREATE TEMPORARY TABLE INVALID_FOREIGN_KEYS(
`TABLE_SCHEMA` VARCHAR(64),
`TABLE_NAME` VARCHAR(64),
`COLUMN_NAME` VARCHAR(64),
`CONSTRAINT_NAME` VARCHAR(64),
`REFERENCED_TABLE_SCHEMA` VARCHAR(64),
`REFERENCED_TABLE_NAME` VARCHAR(64),
`REFERENCED_COLUMN_NAME` VARCHAR(64),
`INVALID_KEY_COUNT` INT,
`INVALID_KEY_SQL` VARCHAR(1024),
`INVALID_KEY_DELETE_SQL` VARCHAR(1024)
);
END IF;
OPEN foreign_key_cursor;
foreign_key_cursor_loop: LOOP
FETCH foreign_key_cursor INTO
TABLE_SCHEMA_VAR,
TABLE_NAME_VAR,
COLUMN_NAME_VAR,
CONSTRAINT_NAME_VAR,
REFERENCED_TABLE_SCHEMA_VAR,
REFERENCED_TABLE_NAME_VAR,
REFERENCED_COLUMN_NAME_VAR;
IF done THEN
LEAVE foreign_key_cursor_loop;
END IF;
SET @from_part = CONCAT('FROM ', '`', TABLE_SCHEMA_VAR, '`.`', TABLE_NAME_VAR, '`', ' AS REFERRING ',
'LEFT JOIN `', REFERENCED_TABLE_SCHEMA_VAR, '`.`', REFERENCED_TABLE_NAME_VAR, '`', ' AS REFERRED ',
'ON (REFERRING', '.`', COLUMN_NAME_VAR, '`', ' = ', 'REFERRED', '.`', REFERENCED_COLUMN_NAME_VAR, '`', ') ',
'WHERE REFERRING', '.`', COLUMN_NAME_VAR, '`', ' IS NOT NULL ',
'AND REFERRED', '.`', REFERENCED_COLUMN_NAME_VAR, '`', ' IS NULL');
SET @full_query = CONCAT('SELECT COUNT(*) ', @from_part, ' INTO @invalid_key_count;');
PREPARE stmt FROM @full_query;
EXECUTE stmt;
IF @invalid_key_count > 0 THEN
INSERT INTO
INVALID_FOREIGN_KEYS
SET
`TABLE_SCHEMA` = TABLE_SCHEMA_VAR,
`TABLE_NAME` = TABLE_NAME_VAR,
`COLUMN_NAME` = COLUMN_NAME_VAR,
`CONSTRAINT_NAME` = CONSTRAINT_NAME_VAR,
`REFERENCED_TABLE_SCHEMA` = REFERENCED_TABLE_SCHEMA_VAR,
`REFERENCED_TABLE_NAME` = REFERENCED_TABLE_NAME_VAR,
`REFERENCED_COLUMN_NAME` = REFERENCED_COLUMN_NAME_VAR,
`INVALID_KEY_COUNT` = @invalid_key_count,
`INVALID_KEY_SQL` = CONCAT('SELECT ',
'REFERRING.', '`', COLUMN_NAME_VAR, '` ', 'AS "Invalid: ', COLUMN_NAME_VAR, '", ',
'REFERRING.* ',
@from_part, ';'),
`INVALID_KEY_DELETE_SQL` = CONCAT('DELETE REFERRING ', @from_part, ';');
END IF;
DEALLOCATE PREPARE stmt;
END LOOP foreign_key_cursor_loop;
END$$
DELIMITER ;
CALL ANALYZE_INVALID_FOREIGN_KEYS('%', '%', 'Y');
DROP PROCEDURE IF EXISTS ANALYZE_INVALID_FOREIGN_KEYS;
SELECT * FROM INVALID_FOREIGN_KEYS;
/* SELECT TABLE_SCHEMA AS DB, TABLE_NAME AS 'Table', COLUMN_NAME AS Col, REFERENCED_TABLE_SCHEMA AS RDB, REFERENCED_TABLE_NAME AS RTable, REFERENCED_COLUMN_NAME AS RCol, INVALID_KEY_COUNT AS Count FROM INVALID_FOREIGN_KEYS ORDER BY count DESC; */
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