PostgreSQL Alter Table: Alter a table to drop a column from it
4. Write a SQL statement to drop the column city from the table locations.
Here is the structure of the table locations.
postgres=# \d locations
Column | Type | Modifiers
----------------+-----------------------+-----------
location_id | numeric(4,0) |
street_address | character varying(40) |
postal_code | character varying(12) |
city | character varying(30) |
state_province | character varying(25) |
country_id | character varying(2) |
region_id | text |
Now execute the following statement.
Sample Solution:
Code:
ALTER TABLE locations
DROP city;
Output:
Now see the structure of the table locations after alteration.
Column | Type | Modifiers ----------------+-----------------------+----------- location_id | numeric(4,0) | street_address | character varying(40) | postal_code | character varying(12) | state_province | character varying(25) | country_id | character varying(2) | region_id | text |
The above result shows that there is no 'city' column; it has been dropped from the table locations.
Have another way to solve this solution? Contribute your code (and comments) through Disqus.
Previous: Write a SQL statement to change the data type of the column region_id to text in the table locations.
Next: Write a SQL statement to change the name of the column state_province to state, keeping the same size and data type and size
What is the difficulty level of this exercise?
It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.
https://www.w3resource.com/postgresql-exercises/alter-table/alter-table-exercise-4.php
- Weekly Trends and Language Statistics
- Weekly Trends and Language Statistics