MySQL SELECT from two tables with a single query
Use UNION to select from two tables. Let us first create a table −
mysql> create table DemoTable1
(
Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
FirstName varchar(20)
);
Query OK, 0 rows affected (0.90 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable1(FirstName) values('Chris') ;
Query OK, 1 row affected (0.19 sec)
mysql> insert into DemoTable1(FirstName) values('Adam');
Query OK, 1 row affected (0.21 sec)
mysql> insert into DemoTable1(FirstName) values('Sam');
Query OK, 1 row affected (0.16 sec)Display all records from the table using select statement −
mysql> select *from DemoTable1;
This will produce the following output −
+----+-----------+
| Id | FirstName |
+----+-----------+
| 1 | Chris |
| 2 | Adam |
| 3 | Sam |
+----+-----------+
3 rows in set (0.00 sec)
Following is the query to create second table −
mysql> create table DemoTable2(
Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
FirstName varchar(20)
);
Query OK, 0 rows affected (1.75 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable2(FirstName) values('John');
Query OK, 1 row affected (0.18 sec)
mysql> insert into DemoTable2(FirstName) values('Tom');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable2(FirstName) values('Bob');
Query OK, 1 row affected (0.50 sec)Display all records from the table using select statement −
mysql> select *from DemoTable2;
This will produce the following output −
+----+-----------+
| Id | FirstName |
+----+-----------+
| 1 | John |
| 2 | Tom |
| 3 | Bob |
+----+-----------+
3 rows in set (0.00 sec)
Following is the query to select from two tables using MySQL UNION −
mysql> (select *from DemoTable1)
union
(select *from DemoTable2)
order by FirstName;
This will produce the following output −
+----+-----------+
| Id | FirstName |
+----+-----------+
| 2 | Adam |
| 3 | Bob |
| 1 | Chris |
| 1 | John |
| 3 | Sam |
| 2 | Tom |
+----+-----------+
6 rows in set (0.00 sec)
Published on 09-Oct-2019 11:48:25
