How to check table constraints?

To check table constraints in a database, the method varies depending on the database management system (DBMS) you are using. Here are the ways to check table constraints in PostgreSQL and SQLite:

PostgreSQL

In PostgreSQL, you can use the \d command in the psql interactive terminal to view the constraints of a table:

\d table_name

For example, to check the constraints of a table named employees:

\d employees

This will display the table structure along with its constraints, including primary keys, foreign keys, unique constraints, and check constraints.

SQLite

In SQLite, you can use the .schema command to view the SQL statement used to create the table, which includes constraints:

.schema table_name

For example, to check the constraints of a table named users:

.schema users

This will show the CREATE TABLE statement, including any constraints defined on the table.

Summary

• PostgreSQL: Use \d table_name in the psql terminal.
• SQLite: Use .schema table_name in the SQLite shell.

These commands will provide you with the necessary information about the constraints applied to the specified table.