Premise: when there is ab, ABC, abcd three fields of the index,
1 - when the search conditions for ab fields, running index is ABC.
2 - when find conditions for ABC fields, running index is ABC.
Above is the result of the I run out!
Solving!!!!!! This is why,

CodePudding user response:

1 - when the search conditions for ab fields, running index is ABC.
- & gt; Excuse me is to use the "select * from"? If the following SQL should use index ab.
Select a, b from [table name] where a=x and b=x

2 - when find conditions for ABC fields, running index is ABC.
- & gt; Normal.