如何使用 Mysql 过程和 Date() 创建存档 Table

Question

我尝试创建一个每天运行一次并存储来自更大 Table 的数据子集的过程。此 table 的名称应使用 CURDATE() 动态创建。

    DROP PROCEDURE daily_backup;
    DELIMITER |
    CREATE PROCEDURE daily_backup()
    BEGIN
      SET @tbl = CONCAT('items_data_', DATE_FORMAT(CURDATE(), '%Y%m%d'));
      SET @s = CONCAT('DROP TABLE IF EXISTS ', @tbl);
      PREPARE stmt FROM @s;
      EXECUTE stmt;

      @s = CONCAT('CREATE TABLE `', @tb1, '` (`id` int(11) NOT NULL,`up` mediumint(9) NOT NULL,`down` mediumint(9) NOT NULL) ENGINE=Archive');

      PREPARE stmt FROM @s;
      EXECUTE stmt;

      SET @s = CONCAT('INSERT INTO ', @tbl, ' SELECT id,up,down FROM items;');
      PREPARE stmt FROM @s;
      EXECUTE stmt;
    END

这些是结果

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '@s = CONCAT('CREATE TABLE `', @tb1, '` (`id` int(11) NOT NULL,`up` mediumint(9) ' at line 8

编辑 // 现在工作

    DROP PROCEDURE daily_backup;
    DELIMITER |
    CREATE PROCEDURE daily_backup()
    BEGIN
      SET @tbl = CONCAT('items_data_', DATE_FORMAT(CURDATE(), '%Y%m%d'));
      SET @s = CONCAT('DROP TABLE IF EXISTS ', @tbl);
      PREPARE stmt FROM @s;
      EXECUTE stmt;

      SET @s = CONCAT('CREATE TABLE `', @tbl, '` (`id` int(11) NOT NULL,`up` mediumint(9) NOT NULL,`down` mediumint(9) NOT NULL) ENGINE=Archive');

      PREPARE stmt FROM @s;
      EXECUTE stmt;

      SET @s = CONCAT('INSERT INTO ', @tbl, ' SELECT id,up,down FROM items;');
      PREPARE stmt FROM @s;
      EXECUTE stmt;
      DEALLOCATE PREPARE stmt;
    END

Answer 1

变量赋值总是需要一个SET命令：

SET @s = CONCAT('CREATE TABLE `', @tbl, '` (`id` int(11) NOT NULL,`up` mediumint(9) NOT NULL,`down` mediumint(9) NOT NULL) ENGINE=Archive');

注意你这个语句里有@tb1，应该是@tbl.

使用后 DEALLOCATE 准备好的语句也是一个好习惯，即

DEALLOCATE PREPARE stmt;

在EXECUTE stmt

之后

如何使用 Mysql 过程和 Date() 创建存档 Table

How to create an Archive Table with a Mysql Procedure and Date()

mysql

date

procedure

archive