The “ALTER TABLE” message in the output proves that the specified command was executed successfully. To do that, execute the “ALTER TABLE RENAME TO” statement as follows: ALTER TABLE employee_data Suppose we want to rename the “employee_data” table to “staff_data”. The “employee_data” table has been created successfully. To verify the table creation, execute the “\dt” command: \dt The “CREATE TABLE” message in the output shows that the specified command was executed successfully. PostgreSQL automatically updates its dependent objects when you rename a table, such as foreign key constraints, views, etc.įor a profound understanding, let’s implement the “ ALTER TABLE RENAME TO” statement practically.Įxample: How Do I Rename a Table in Postgres?įollow the below provided stepwise instructions to rename a table in Postgres:įirst, we will create a sample Postgres table named “employee_data” with three columns: employee_id, employee_name, and employee_age: CREATE TABLE employee_data( Use the IF EXISTS option to avoid the “table does not exist” error. In simple terms, each table will be renamed one by one. To rename more than one table, you must execute the “ ALTER TABLE RENAME TO” statement several times. You can’t rename multiple tables in one go. The following points will assist Postgres users in understanding the "ALTER TABLE RENAME TO" statement in a better way: Consequently, if a table with the specified name does not exist, a notice will be issued rather than an error. The IF EXISTS option is used with the ALTER TABLE command in the above syntax. Postgres experts prefer to use the IF EXISTS option with the ALTER TABLE statement to avoid the “table does not exist” error: ALTER TABLE IF EXISTS tab_name new_tab_name represents a new/modified name of the targeted table. tab_name represents a table to be renamed. To rename a particular table in PostgreSQL, use the RENAME TO clause in conjunction with the ALTER TABLE statement: ALTER TABLE tab_name This blog post will teach you how to rename a table in Postgres through practical examples. A Postgres table can be renamed using the ALTER TABLE command. For instance, the CREATE TABLE statement creates a table, the DROP TABLE deletes a table, and the ALTER TABLE updates an existing table. Alternatively, you can add constraints later (see below) after you've filled in the new column correctly.PostgreSQL provides different commands/statements to perform the different operations on the Postgres tables. Keep in mind however that the default value must satisfy the given constraints, or the ADD will fail. In fact all the options that can be applied to a column description in CREATE TABLE can be used here. You can also define constraints on the column at the same time, using the usual syntax:ĪLTER TABLE products ADD COLUMN description text CHECK (description '') To avoid a potentially lengthy update operation, particularly if you intend to fill the column with mostly nondefault values anyway, it may be preferable to add the column with no default, insert the correct values using UPDATE, and then add any desired default as described below. However, if the default value is volatile (e.g., clock_timestamp()) each row will need to be updated with the value calculated at the time ALTER TABLE is executed. Instead, the default value will be returned the next time the row is accessed, and applied when the table is rewritten, making the ALTER TABLE very fast even on large tables. From PostgreSQL 11, adding a column with a constant default value no longer means that each row of the table needs to be updated when the ALTER TABLE statement is executed.
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