将唯一数据添加到sql表

I am learning about sql databases. I am using mysql.

我正在学习sql数据库。我正在使用mysql。

I have designed the tables, and queries. I am now working on the code to put stuff into the database.

我设计了表格和查询。我现在正在研究将内容放入数据库的代码。

I can not work out how to ensure that a record is unique when I have a text field. I tried to mark the part of the record that was not the pk (primary key) as unique, but when it is text it complains that it is not fixed length. I then played with the idea of conditionals in a stored procedure, but could not get it to work.

当我有一个文本字段时,我无法确定如何确保记录是唯一的。我试图将不是pk(主键)的记录部分标记为唯一,但是当它是文本时,它会抱怨它不是固定长度。然后,我在存储过程中使用条件的概念,但无法使其工作。

DELIMITER $$

DROP PROCEDURE IF EXISTS `experiment1`.`add_zzzz`$$
CREATE PROCEDURE `experiment1`.`add_zzzz` (IN v INT, IN n TEXT)
BEGIN

IF EXISTS (
  SELECT value, name 
  FROM zzzz 
  WHERE value=v AND name=n
)
THEN
ELSE
  INSERT INTO zzzz(value,name)
  VALUES v,n;
END IF;

END$$

DELIMITER ;

So anyone know what I am doing wrong?

所以任何人都知道我做错了什么?

1 个解决方案

#1

VARCHAR is not fixed and you can use unique index with it

VARCHAR未修复,您可以使用唯一索引

more on http://www.w3schools.com/sql/sql_unique.asp

更多信息,请访问http://www.w3schools.com/sql/sql_unique.asp

you can also use INSERT ignore

你也可以使用INSERT ignore

http://dev.mysql.com/doc/refman/5.5/en/insert.html

#1