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索引的最左前缀原理
2022-07-29 04:08:00 【Fanzongshen】
在a,b,c三个字段上建立一个联合索引(a,b,c)
什么语句会走index1索引呢?
select * from table where a = '1'
select * from table where a = '1' and b = ‘2’
select * from table where a = '1' and b = ‘2’ and c='3'
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