How to create a temporary MySQL table in a SELECT statement without a separate CREATE TABLE?
To create a temporary table in a SELECT statement we use TEMPORARY keyword.
This temporary table will be visible for the current session and whenever a session is closed, it is automatically destroyed. Two sessions can use the same temporary table.
Creating a table.
mysql> create table MyTableDemo
-> (
-> id int,
-> Name varchar(100)
-> );
Query OK, 0 rows affected (0.69 sec)
Inserting some records.
mysql> insert into MyTableDemo values(1,'John');
Query OK, 1 row affected (0.18 sec)
mysql> insert into MyTableDemo values(2,'Carol');
Query OK, 1 row affected (0.13 sec)
mysql> insert into MyTableDemo values(3,'Bob');
Query OK, 1 row affected (0.12 sec)
To display all records.
mysql> select *from MyTemporaryTableDemo;
Here is the output.
+------+-------+
| id | Name |
+------+-------+
| 1 | John |
| 2 | Carol |
| 3 | Bob |
+------+-------+
3 rows in set (0.00 sec)
The syntax to create a temporary table.
CREATE TEMPORARY TABLE IF NOT EXISTS yourTemporaryTableName AS (SELECT * FROM yourTableName);
Let us now implement the above syntax in the following query −
mysql> CREATE TEMPORARY TABLE IF NOT EXISTS MyTemporaryTableDemo AS (SELECT * FROM MyTableDemo);
Query OK, 3 rows affected (0.01 sec)
Records: 3 Duplicates: 0 Warnings: 0
To check if all records are copied successfully.
mysql> select *from MyTemporaryTableDemo;
Here is the output.
+------+-------+
| id | Name |
+------+-------+
| 1 | John |
| 2 | Carol |
| 3 | Bob |
+------+-------+
3 rows in set (0.00 sec)
Published on 29-Nov-2018 07:19:22
