Stored procedure to remove rows in chunks until a certain value is reached.

remove-processed.sql

CREATE DEFINER=`admin`@`10.0.0.1` PROCEDURE `removeProcessed`(table_name VARCHAR(255), keyField VARCHAR(255), maxId INT, num_rows INT)
BEGIN
    SET @table_name = table_name;
    SET @keyField = keyField;
    SET @maxId = maxId;
    SET @num_rows = num_rows;

    SET @sql_text1 = concat('SELECT MIN(',@keyField,') INTO @a FROM ',@table_name);
    PREPARE stmt1 FROM @sql_text1;
    EXECUTE stmt1;
    DEALLOCATE PREPARE stmt1;

    loop_label:  LOOP
        SET @z = NULL;
        SET @sql_text2 = concat('SELECT ',@keyField,' INTO @z FROM ',@table_name,' WHERE ',@keyField,' >= ',@a,' ORDER BY ',@keyField,' LIMIT ',@num_rows,',1');
        PREPARE stmt2 FROM @sql_text2;
        EXECUTE stmt2;
        DEALLOCATE PREPARE stmt2;

        If @z is null THEN
            LEAVE loop_label;
        ELSEIF @z = "" THEN
            LEAVE loop_label;
        ELSEIF @z > @maxId THEN
            LEAVE loop_label;
        END IF;

        SET @sql_text3 = concat('DELETE FROM ',@table_name,' WHERE ',@keyField,' >= ',@a,' AND ',@keyField,' <= ',@z);
        PREPARE stmt3 FROM @sql_text3;
        EXECUTE stmt3;
        DEALLOCATE PREPARE stmt3;

        SET @a = @z;
        SELECT SLEEP(1);
    END LOOP;

    SET @sql_text4 = concat('DELETE FROM ',@table_name,' WHERE ',@keyField,' <= ',@maxId);
    PREPARE stmt4 FROM @sql_text4;
    EXECUTE stmt4;
    DEALLOCATE PREPARE stmt4;
END