Postgres and Open Source Experts

In PostgreSQL, the “\d” command, “\d+” command, “information_schema”, and “pgAdmin” are used to list all columns of a table.

“\List”, “\l”, and “pg_database” is used in SQL Shell to get the database list. While to switch databases in SQL Shell, the “\c” and “\connect” commands are used.

This post demonstrates stepwise instructions for importing CSV to Postgres or exporting Postgres tables to CSV files using pgAdmin.

PostgreSQL allows us to import CSV files to Postgres tables or export Postgres tables to CSV files using SQL Shell (psql). To do that, the “\COPY” command is used.

Postgres provides an INNER JOIN clause to combine the records of multiple tables based on a specific condition/criteria.

Postgres provides a couple of ways to drop all the tables of a Postgres database, such as dropping the complete schema or removing the schema’s tables individually.

In PostgreSQL, the COALESCE() function and the IS NULL operator are used to find and replace the null values with some default values.

The INTERVAL keyword is used to define an interval in Postgres. This blog explained the usage of the INTERVAL data type in Postgres via suitable examples.

The ALTER TABLE command in PostgreSQL is used to alter the tables' structure, such as adding columns, renaming columns/tables, dropping columns, modifying constraints, etc.

In Postgres, the standard “information_schema”, a system catalog table named “pg_namespace”, and the “\dn” command is used to get the list of available schemas.