The metacommand returns only user-created tables, while the SELECT query includes system and user-defined tables. Both these queries result in the same output. In PostgreSQL, we can list the tables in two ways: using the psql meta-commands of simple SELECT clause query on the table pg_tables of pg_catalog schema. Besides this, the columns schemaname and tableowner contain the table that belongs to which schema type and who owns this table. For example, in our table, the column hastriggers have the value f, which means that the current table educba does not define any triggers. Most of the fields’ answers have the values t and f, which are boolean-type parameters specifying whether the table has that property. The pg_tables table displays the table name and many properties related to the table, which include schemaname, tableowner, tablespace, hasindexes, hasrules, hastriggers, and rowsecurity. We can only expect to retrieve the user-defined table “educba,” which we created. The output of the above query will be as shown below. WHERE schemaname != 'information_schema' AND We should arrange our query in the following manner: SELECT * FROM pg_catalog.pg_tables What if we only want to retrieve user-defined tables, not system tables? We must apply the constraint in the WHERE clause specifying that the tables should not belong to pg_catalog or information_schema schemas, as these two schemas only have internal system tables. It will be a long list displaying all the tables that are system tables and user-defined tables. The above query will produce an output similar to the one shown below. When querying a table located in a different database or schema than the one we are currently connected to, we need to explicitly specify the schema name followed by a dot (.) and the table name to retrieve the list of tables. All table information is stored in the pg_tables table of the pg_catalog schema. Now, we will learn how to use the simple SQL query of SELECT to retrieve information about all the tables in our current database. So we can see now that our table has been added successfully. We can check if the table was added by entering the command: \dt or \dtables Let’s create a new table and check if we can retrieve it. Since no tables are present in our newly created database, the system states that it did not find any relations. Metacommand to list out the user-created or user-defined tables. Metacommands are short commands that are compact and easy for database administrators as the psql evaluates them and converts them to SQL queries if required and stored in system tables. Now, we will learn how to list the tables using psql metacommands. Listing Out Tables using psql meta-commands Now, fire command \c educational_platform Now, to switch between databases and use the database of your choice, you can use the command \c or \connect and the name of the database to which you want to connect. Let’s verify if our database has been created by entering the \l command. For this, we will fire the following command. For example, let us create a database named educational_platform. You can create a new database using the command createdb and the name. The default databases are Postgres, template0, and template1, while I created the demo database previously. It will list all the schemas and databases, and the output will be like this. The command to list all databases and schemas for this. The next step is to check all the databases present in your current database server. The output will be somewhat like the one below. Then open the psql shell by typing the command psqlĪnd click on enter. You must first open the terminal, log in to PostgreSQL with your username and command, sudo su – postgresĪnd then enter your password. We will see how we can use both of these methods one by one. In PostgreSQL, we can retrieve the list of tables by either using the \dt command when you are using psql or retrieving the list of tables using the SELECt query from the pg_tables table of pg_catalog schema. However, in PostgreSQL, there is no such query. Please reach out to David on our slack to discuss what you want to contribute.ĭata School wants a comprehensive post to help people show their tables in Postgres.If you are familiar with MySQL before then, you must consider using the SHOW TABLES query to retrieve the list of all the tables in the current database. Share your story about working through this problem at work.We are looking for two types of contributions:
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