Force InnoDB to recheck foreign keys on a table/tables?

Question

I have a set of InnoDB tables that I periodically need to maintain by removing some rows and inserting others. Several of the tables have foreign key constra

Answer 1

The same check but for invalid UNIQUE keys analysis:

--> Small bug/feature: It will report duplicate nulls also. (While mysql allows duplicate nulls).

DELIMITER $$

DROP PROCEDURE IF EXISTS ANALYZE_INVALID_UNIQUE_KEYS$$

CREATE
    PROCEDURE `ANALYZE_INVALID_UNIQUE_KEYS`(
        checked_database_name VARCHAR(64), 
        checked_table_name VARCHAR(64))

    LANGUAGE SQL
    NOT DETERMINISTIC
    READS SQL DATA

    BEGIN
        DECLARE TABLE_SCHEMA_VAR VARCHAR(64);
        DECLARE TABLE_NAME_VAR VARCHAR(64);
        DECLARE COLUMN_NAMES_VAR VARCHAR(1000); 
        DECLARE CONSTRAINT_NAME_VAR VARCHAR(64);

        DECLARE done INT DEFAULT 0;

        DECLARE unique_key_cursor CURSOR FOR
            select kcu.table_schema sch,
                   kcu.table_name tbl, 
                   group_concat(kcu.column_name) colName, 
                   kcu.constraint_name constName
            from 
                information_schema.table_constraints tc
            join 
                information_schema.key_column_usage kcu 
            on 
                kcu.constraint_name=tc.constraint_name 
                and kcu.constraint_schema=tc.constraint_schema
                and kcu.table_name=tc.table_name  
            where 
                kcu.table_schema like checked_database_name 
                and kcu.table_name like checked_table_name 
                and tc.constraint_type="UNIQUE" group by sch, tbl, constName;

        DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;

        DROP TEMPORARY TABLE IF EXISTS INVALID_UNIQUE_KEYS;
        CREATE TEMPORARY TABLE INVALID_UNIQUE_KEYS(
            `TABLE_SCHEMA` VARCHAR(64), 
            `TABLE_NAME` VARCHAR(64), 
            `COLUMN_NAMES` VARCHAR(1000), 
            `CONSTRAINT_NAME` VARCHAR(64),
            `INVALID_KEY_COUNT` INT
        );



        OPEN unique_key_cursor;
        unique_key_cursor_loop: LOOP
            FETCH unique_key_cursor INTO 
            TABLE_SCHEMA_VAR, 
            TABLE_NAME_VAR, 
            COLUMN_NAMES_VAR, 
            CONSTRAINT_NAME_VAR;
            IF done THEN
                LEAVE unique_key_cursor_loop;
            END IF;

            SET @from_part = CONCAT('FROM (SELECT COUNT(*) counter FROM', '`', TABLE_SCHEMA_VAR, '`.`', TABLE_NAME_VAR, '`', 
                    ' GROUP BY ', COLUMN_NAMES_VAR , ') as s where s.counter > 1');
            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_UNIQUE_KEYS 
                SET 
                    `TABLE_SCHEMA` = TABLE_SCHEMA_VAR, 
                    `TABLE_NAME` = TABLE_NAME_VAR, 
                    `COLUMN_NAMES` = COLUMN_NAMES_VAR, 
                    `CONSTRAINT_NAME` = CONSTRAINT_NAME_VAR, 
                    `INVALID_KEY_COUNT` = @invalid_key_count;
            END IF;
            DEALLOCATE PREPARE stmt; 

        END LOOP unique_key_cursor_loop;
    END$$

DELIMITER ;

CALL ANALYZE_INVALID_UNIQUE_KEYS('%', '%');
DROP PROCEDURE IF EXISTS ANALYZE_INVALID_UNIQUE_KEYS;

SELECT * FROM INVALID_UNIQUE_KEYS;