For MySQL multi table query, the data found by indexing is different from that without index

What is it like sql And data , Post it to see

https://bbs.csdn.net/topics/392158859, Turn out an old post , Index file corruption may cause the difference between the results with and without index

Another possibility is , Full text index word segmentation may be similar to like The results are different , I don't know what your situation is

The index has nothing to do with the queried data , But it has something to do with the time when the data is queried , So your question should have nothing to do with the index ！

First, it's impossible , Indexing is just a way to improve retrieval efficiency . The result is different, just the appearance ,sql Adding an index leaves out the fields with empty index fields , No, it's all found . If help , Please accept ！

Indexes are built on Columns , A data structure that sorts columns . The function is to speed up the query .
There are more data in the table , The index is used only when the data in the column is neat Small tables or fields often change, which is unnecessary .
where There are conditions <> !=
where There are conditions Aggregate functions
Fuzzy query %xxx
There are a lot of duplicate data in the column When the index is invalid ;
Neither will affect the query data Just for efficiency It should be you sql The problem has nothing to do with the index

No plan, no truth , Unless BUG 了 . this ... You first upgrade to the latest version to see .