Is there a way to convert Integer field into Varchar without losing data in MySQL?

You can use ALTER command to convert Integer into Varchar. Let us first create a table

mysql> create table DemoTable
(
   UserId int,
   UserFirstName varchar(20),
   UserLastName varchar(20),
   UserAge int
);
Query OK, 0 rows affected (0.73 sec)

Now check the description of table using DESC command:

mysql> desc DemoTable;

This will produce the following output −

+---------------+-------------+------+-----+---------+-------+
| Field         | Type        | Null | Key | Default | Extra |
+---------------+-------------+------+-----+---------+-------+
| UserId        | int(11)     | YES  |     | NULL    |       |
| UserFirstName | varchar(20) | YES  |     | NULL    |       |
| UserLastName  | varchar(20) | YES  |     | NULL    |       |
| UserAge       | int(11)     | YES  |     | NULL    |       |
+---------------+-------------+------+-----+---------+-------+
4 rows in set (0.17 sec)

Now you can change the integer data type to varchar without losing data:

mysql> alter table DemoTable change UserId UserId varchar(20);
Query OK, 0 rows affected (1.35 sec)
Records: 0 Duplicates: 0 Warnings: 0

Check the table description:

mysql> desc DemoTable;

This will produce the following output −

+---------------+-------------+------+-----+---------+-------+
| Field         | Type        | Null | Key | Default | Extra |
+---------------+-------------+------+-----+---------+-------+
| UserId        | varchar(20) | YES  |     | NULL    |       |
| UserFirstName | varchar(20) | YES  |     | NULL    |       |
| UserLastName  | varchar(20) | YES  |     | NULL    |       |
| UserAge       | int(11)     | YES  |     | NULL    |       |
+---------------+-------------+------+-----+---------+-------+
4 rows in set (0.00 sec)

Chandu yadav

Published on 29-Apr-2019 08:35:39

• Related Questions & Answers
• Convert varchar to unsigned integer in MySQL
• In MySQL, is there a way to turn column records into a list?
• Is there a way in MySQL to reverse a boolean field with a single query?
• Searching for an integer value in a varchar field in MySQL?
• Convert VARCHAR data to MySQL date format?
• Is there a way to know your current username in MySQL?
• How to change the column position of MySQL table without losing column data?
• Is there any way to embed a PDF file into an HTML5 page?
• What is JavaScript’s highest integer value that a Number can go to without losing precision?
• Convert varchar to date in MySQL?
• Sorting varchar field numerically in MySQL?
• Is there a way to select a value which matches partially in MySQL?
• Is there an easy way to rename a table in a MySQL procedure?
• Is there a way to list collections in MongoDB?
• Is there a MySQL command to convert a string to lowercase?