DELETE - (PostgreSQL Queries)

The DELETE statement is used to delete one or more rows from a table in a PostgreSQL database. In this tutorial, we'll cover the syntax, example, output, explanation, use, important points, and summary of the DELETE statement in PostgreSQL queries.

Syntax

DELETE FROM table_name
WHERE condition;

• table_name: The name of the table to delete rows from.
• condition: The condition that the rows to be deleted must meet.

Example

Let's take a look at an example of using DELETE.

DELETE FROM users
WHERE id = 1;

In this example, we're deleting a row from the users table where the id is equal to 1.

Output

The output of a DELETE statement is the number of rows that were affected by the statement.

Explanation

The DELETE statement is used to delete one or more rows from a table in a PostgreSQL database. The WHERE clause is used to specify the condition that the rows to be deleted must meet.

If the WHERE clause is omitted, all the rows in the table will be deleted.

Use

The DELETE statement is commonly used to remove unwanted data from a table or to delete data that is no longer needed.

Important Points

• Deleting data using DELETE is permanent and cannot be undone.
• Use caution when deleting data from a table to avoid accidentally deleting important data.
• If the table being deleted from has foreign key constraints set up, the related rows in the other tables must also be deleted or changed before the row can be deleted.
• If you only want to remove specific columns from a row while keeping the rest of the row intact, you should use the UPDATE statement instead.

Summary

In this tutorial, we discussed the DELETE statement in PostgreSQL queries. We covered the syntax, example, output, explanation, use, important points, and summary of the DELETE statement. With this knowledge, you can now use the DELETE statement to remove unwanted data from a table or delete data that is no longer needed in your PostgreSQL queries.