MySQL Alter Table Statement Exercises: Change the data type of the column country_id to integer in the table locations

MySQL Alter Table Statement: Exercise-5 with Solution

Write a MySQL statement change the data type of the column country_id to integer in the table locations.

Here is the structure of the table locations.

mysql> SHOW COLUMNS FROM locations;
+----------------+--------------+------+-----+---------+-------+
| Field          | Type         | Null | Key | Default | Extra |
+----------------+--------------+------+-----+---------+-------+
| LOCATION_ID    | decimal(4,0) | YES  |     | NULL    |       |
| STREET_ADDRESS | varchar(40)  | YES  |     | NULL    |       |
| POSTAL_CODE    | varchar(12)  | YES  |     | NULL    |       |
| CITY           | varchar(30)  | YES  |     | NULL    |       |
| STATE_PROVINCE | varchar(25)  | YES  |     | NULL    |       |
| COUNTRY_ID     | varchar(2)   | YES  |     | NULL    |       |
+----------------+--------------+------+-----+---------+-------+

Code:

 -- This SQL statement is used to alter the 'locations' table by modifying the data type of an existing column.
-- The 'country_id' column's data type is changed to INT (integer).

ALTER TABLE locations

-- Modify the data type of the 'country_id' column to INT (integer).
MODIFY country_id INT;

Let execute the above code in MySQL command prompt

Now see the structure of the table locations after alteration.

mysql> SHOW COLUMNS FROM locations;
+----------------+--------------+------+-----+---------+-------+
| Field          | Type         | Null | Key | Default | Extra |
+----------------+--------------+------+-----+---------+-------+
| LOCATION_ID    | decimal(4,0) | YES  |     | NULL    |       |
| STREET_ADDRESS | varchar(40)  | YES  |     | NULL    |       |
| POSTAL_CODE    | varchar(12)  | YES  |     | NULL    |       |
| CITY           | varchar(30)  | YES  |     | NULL    |       |
| STATE_PROVINCE | varchar(25)  | YES  |     | NULL    |       |
| country_id     | int(11)      | YES  |     | NULL    |       |
+----------------+--------------+------+-----+---------+-------+

Explanation:

Here's a brief explanation of the above MySQL code:

• ALTER TABLE locations: This part of the statement indicates that we want to change the structure of the 'locations' table.
• MODIFY country_id INT;: This specifies the action to be taken. It modifies the data type of the 'country_id' column to INT (integer).

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