Question

我想删除并创建一个在存储过程参数中传递名称的表。我写了以下存储过程。

CREATE DATABASE db1;
USE db1;
DROP PROCEDURE IF EXISTS drop_create;
DELIMITER $$  
CREATE PROCEDURE drop_create(IN tbname VARCHAR(15))
BEGIN

SET @droptable = CONCAT ("DROP TABLE IF EXISTS ", tbname);
SET @createtable = CONCAT("CREATE TABLE ", tbname, " (c0 INT PRIMARY KEY,  c1 VARCHAR(16000)" );

PREPARE deletetb FROM @droptable;
PREPARE createtb FROM @createtable ;

EXECUTE deletetb ; 
EXECUTE createtb; 

DEALLOCATE PREPARE createtb ;
DEALLOCATE PREPARE deletetb ;

END $$
DELIMITER ;

当我执行它时，我得到以下错误。

Call db1.drop_create('abd');
ERROR 1064 (42000): 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 '' at line 1

显然，我无法在上面的SP中找到语法错误。我究竟做错了什么？问题必须出现在与CREATE TABLE相关的语句中，因为当我对第8,10,12和4行进行注释时13然后SP工作正常。我正在使用Mysql 5.6

Answer 1

糟糕！以下语句中缺少右括号：

SET @createtable = CONCAT("CREATE TABLE ", tbname, " (c0 INT PRIMARY KEY, c1 VARCHAR(16000)" );

应该是：

SET @createtable = CONCAT("CREATE TABLE ", tbname, " (c0 INT PRIMARY KEY, c1 VARCHAR(16000))" );
                                                                                           ^

Answer 2

您的代码有很多错误。正在按如下方式进行更正。 VARCHAR不能假设1600.它可以是550周围。

DELIMITER $$  
CREATE DATABASE db1;
USE db1;
DROP PROCEDURE IF EXISTS drop_create;

CREATE PROCEDURE drop_create(IN tbname VARCHAR(15))
BEGIN

SET @droptable = CONCAT ('DROP TABLE IF EXISTS  ', tbname);
PREPARE deletetb FROM @droptable;
EXECUTE deletetb ;
DEALLOCATE PREPARE deletetb ;

SET @createtable = CONCAT('CREATE TABLE ', tbname, ' (c0 INT  NOT NULL AUTO_INCREMENT, c1 VARCHAR(550),PRIMARY KEY(c0))ENGINE=InnoDB DEFAULT CHARSET=utf8');
PREPARE createtb FROM @createtable ; 
EXECUTE createtb;
DEALLOCATE PREPARE createtb ;

END $$
DELIMITER ;

现在尝试。代码应该运行良好。

MySQL：如何在存储过程中动态创建表？

2 个答案: