本文介绍了将事物的顺序存储在MySQL中的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
假设我有一个如下表:
name VARCHAR(50) PRIMARY KEY NOT NULL
ordernum TINYINT UNSIGNED NOT NULL
也可以说我有3行.
something - 1
somethingelse - 2
somethingmore - 3
如果我想插入另一个名为something1
的条目,并将其ordernum设置为2,如何对ordernum为2或更大的所有行进行重新排序?即somethingelse
变为具有3的序号,而somethingmore
变为具有4的序号?
If i want to insert another entry called something1
, and give it an ordernum of 2, how do I reorder all the rows that has an ordernum of 2 or greater? i.e. somethingelse
becomes has an ordernum of 3, and somethingmore
has an ordernum of 4?
我听说您可以通过FIELD()
来做到这一点,但是我不确定该怎么做.
I've heard the you can do it via FIELD()
, but I'm unsure how to exactly.
如果不可能,可以用PHP吗?
If it's not possible, anywy to do it in PHP?
推荐答案
在您的示例中:
UPDATE `table` SET `ordernum` = `ordernum` + 1 WHERE `ordernum` >= 2
INSERT INTO `table` (`name`, `ordernum`) VALUES ('something1', 2)
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