Introduction to the method of converting varchar type to int type in Mysql database

In the last article, I told you about the slow query caused by converting int to varchar in the databaseMySQL. This article will introduce to you the conversion of varchar in the Mysql database. Let’s take a look at the method of converting type to int type!

mysql provides us with twotype conversionfunctions: CAST and CONVERT. How can we let go of ready-made things?

The CAST() and CONVERT() functions can be used to obtain a value of one type and produce a value of another type.

This type can be one of the following values:

BINARY[(N)] CHAR[(N)] DATE DATETIME DECIMAL SIGNED [INTEGER] TIME UNSIGNED [INTEGER]

So we can also use CAST to solve the problem:

select server_id from cardserver where game_id = 1 order by CAST(server_id as SIGNED) desc limit 10

You can also use CONVERT to solve this problem:

select server_id from cardserver where game_id = 1 order by CONVERT(server_id,SIGNED) desc limit 10

PS:
mysql varchar type conversion int type

select * from gyzd_yysinfo order by cast(yysid as SIGNED INTEGER)

or

select * from gyzd_yysinfo order by cast(yysid as UNSIGNED INTEGER)

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