Changing Column in MySQL from int to double?
To change the column in MySQL from int to double you need to use ALTER TABLE command.
The syntax is as follows:
ALTER TABLE yourTableName modify column yourColumnName DOUBLE NOT NULL;
If you want NULL value then remove NOT NULL from the above syntax. The syntax is as follows:
ALTER TABLE yourTableName modify column yourColumnName DOUBLE;
To understand the above syntax, let us create a table. The query to create a table is as follows:
mysql> create table IntToDoubleDemo
-> (
-> Id int NOT NULL AUTO_INCREMENT,
-> Name varchar(10),
-> CylinderVolume int,
-> PRIMARY KEY(Id)
-> );
Query OK, 0 rows affected (0.63 sec)
Check the description of the table using DESC command. The syntax is as follows:
DESC yourTableName;
Apply the above query for your table to get the description of the table:
mysql> desc IntToDoubleDemo;
The following is the output:
+----------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+-------------+------+-----+---------+----------------+
| Id | int(11) | NO | PRI | NULL | auto_increment |
| Name | varchar(10) | YES | | NULL | |
| CylinderVolume | int(11) | YES | | NULL | |
+----------------+-------------+------+-----+---------+----------------+
3 rows in set (0.18 sec)
Look at the above sample output, the field ‘CylinderVolume’ is a type of int. Now you can convert from int to double.
Change the column in MySQL from int to double. The query is as follows:
mysql> alter table IntToDoubleDemo MODIFY COLUMN CylinderVolume double NOT NULL;
Query OK, 0 rows affected (2.79 sec)
Records: 0 Duplicates: 0 Warnings: 0
Once again check the description of the table. The query is as follows:
mysql> desc IntToDoubleDemo\G
The following is the output:
*************************** 1. row ***************************
Field: Id
Type: int(11)
Null: NO
Key: PRI
Default: NULL
Extra: auto_increment
*************************** 2. row ***************************
Field: Name
Type: varchar(10)
Null: YES
Key:
Default: NULL
Extra:
*************************** 3. row ***************************
Field: CylinderVolume
Type: double
Null: NO
Key:
Default: NULL
Extra:
3 rows in set (0.00 sec)
Published on 26-Feb-2019 11:51:24
