MySQL 从文件中读取参数以用于 select 语句

Question

I have a select query as follows:

select * from abc where id IN ($list);

The problem with the length of variable $list , it may have a length of 4000-5000 characters, as a result of which the length of actually executed query increases and its get pretty slow.

Is there a method to store the values of $list in a file and ask MySQL to read it from that file, similar to LOAD DATA INFILE 'file_name' for insertion into table?

Answer 1

Yes, you can (TM)!

• First step: Use CREATE TEMPORARY TABLE temp (id ... PRIMARY KEY) and LOAD DATA INFILE ... to create and fill a temporary table holding your value list
• Second step: Run SELECT abc.id FROM abc INNER JOIN temp ON abc.id=temp.id

I have the strong impression this only checks out as a win, if you use the same value list quite a few times.