mysql - 自动计算模式中缺失和空白的数量

Question

我想创建一段代码来计算我的架构中缺失和空白的数量。

我的想法是使用concat创建脚本来计算一列上的数字，然后循环遍历行数。

创建一个包含要执行的指令的表是可以的，但我在循环中挣扎。在脚本中包含P1时，没有任何反应。

有什么想法吗？

DROP TABLE IF EXISTS workspace.instructions;
CREATE TABLE workspace.instructions (
  instructions varchar(3000)
) ;

insert into  workspace.instructions
select 
CONCAT('insert into  workspace.missing_rows
select
    sum(case when ', column_name, ' is null then 1 else 0 end) as nb_missing,
    sum(case when ', column_name,' = "" then 1 else 0 end) as nb_blank,
    "', table_name, '" as table_name0,
    "', column_name, '" as column_name0
from my_schema.', table_name, '; ') as instruction
    from information_schema.COLUMNS where TABLE_SCHEMA = 'my_table' and DATA_TYPE = 'varchar';
-- 57 rows

DROP TABLE IF EXISTS workspace.missing_rows;
CREATE TABLE workspace.missing_rows (
  table_name0 varchar(64),
  column_name0 varchar(64),
    nb_missing int,
    nb_blank int
) ;

DROP TABLE IF EXISTS workspace.test_loop;
CREATE TABLE workspace.test_loop (
  test varchar(1500)
) ;

DROP PROCEDURE IF EXISTS doiterate;
DELIMITER $$
CREATE PROCEDURE doiterate(p1 INT)
BEGIN
  label1: LOOP
    SET p1 = p1 + 1;

    SELECT @s = (select instructions from workspace.instructions limit p1, 1);

    PREPARE stmt1 FROM @s; 
    EXECUTE stmt1; 
    DEALLOCATE PREPARE stmt1; 

    IF p1 < 57 THEN ITERATE label1; END IF;

    LEAVE label1;
  END LOOP label1;
END;

call doiterate(0);

select * from workspace.missing_rows;