Select Data from One Table Where Column Values Match Another Table in MySQL

For this, you can use subquery along with EXISTS. Let us first create a table −

mysql> create table DemoTable1
   -> (
   -> Id int,
   -> SubjectName varchar(20)
   -> );
Query OK, 0 rows affected (0.58 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable1 values(111,'MySQL');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable1 values(112,'MongoDB');
Query OK, 1 row affected (0.15 sec)
mysql> insert into DemoTable1 values(113,'Java');
Query OK, 1 row affected (0.17 sec)
mysql> insert into DemoTable1 values(114,'C');
Query OK, 1 row affected (0.27 sec)
mysql> insert into DemoTable1 values(115,'MySQL');
Query OK, 1 row affected (0.23 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable1;

This will produce the following output −

+------+-------------+
| Id   | SubjectName |
+------+-------------+
|  111 | MySQL       |
|  112 | MongoDB     |
|  113 | Java        |
|  114 | C           |
|  115 | MySQL       |
+------+-------------+
5 rows in set (0.00 sec)

Here is the query to create second table −

mysql> create table DemoTable2
    -> (
    -> FirstName varchar(20),
    -> StudentSubject varchar(20)
    -> );
Query OK, 0 rows affected (0.73 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable2 values('Chris','MySQL');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable2 values('Bob','MySQL');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable2 values('Sam','MySQL');
Query OK, 1 row affected (0.12 sec)
mysql> insert into DemoTable2 values('Carol','C');
Query OK, 1 row affected (0.19 sec)

Display all records from the table using select statement −

mysql> select * from DemoTable2;

This will produce the following output −

+-----------+----------------+
| FirstName | StudentSubject |
+-----------+----------------+
| Chris     | MySQL          |
| Bob       | MySQL          |
| Sam       | MySQL          |
| Carol     | C              |
+-----------+----------------+
4 rows in set (0.00 sec)

Here is the query to select data from one table only where column values from that table match the column values of another table −

mysql> select Id from DemoTable1
   -> where exists
   -> (
   -> select 1 from DemoTable2
   -> where SubjectName=StudentSubject
   -> );

This will produce the following output −

+------+
| Id   |
+------+
|  111 |
|  114 |
|  115 |
+------+
3 rows in set (0.00 sec)