Mysql in and mysqlin

Mysql in and mysqlin

The following describes the usage of MySQL in:

They are followed by a table (record set) after the in keyword and a string set after the in keyword.

Let's start with a table.

First, describe the structure of the three tables:

S (sno, sname. sex, age, dept) // student information table

C (cno, cname, tname) // course information table

SC (sno, cno, grade) // optional course information table

Update SC set grade = 0 where SC. cno in (select cno from c where c. cname = 'physical ') and SC. grade <60; for example, this SQL statement sets the physical fail score to 0.

In this example, the in is followed by a temporary table generated by the select statement.

Well, now let's take a look at the following in followed by a string set, which is not necessarily a string set.

Select * from s where sname in ('aaa', 'bbb ', 'ccc ');