MySQL查询来计算多个表中的所有记录

Question

我想计算所有表中的所有记录我试过了，但这不起作用。

DELIMITER $
CREATE FUNCTION countr(p_tablename varchar(10)) RETURN int(10) BEGIN DECLARE ra int; DECLARE table_count INT;
SET ra=
  (SELECT COUNT(*) INTO table_count
   FROM information_schema.tables
   WHERE TABLE_SCHEMA = 'dest_northwind'
     AND TABLE_NAME = p_tablename); RETURN ra; END$ DELIMITER ;

Answer 1

这会做到...

SELECT SUM(TABLE_ROWS) 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_SCHEMA = DATABASE();

更新 - 发问者希望只获取表格子集的行，因此我更新了它以包含各个表格的总和或这些表格自己的计数。

表行总和...

SELECT SUM(TABLE_ROWS) 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_SCHEMA = DATABASE()
    AND TABLE_NAME IN ('Table2','Table1');

表格行...

SELECT TABLE_NAME,SUM(TABLE_ROWS) 
FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_SCHEMA = DATABASE()
    AND TABLE_NAME IN ('Table2','Table1')
GROUP BY TABLE_NAME;