![]() The OWNED BY in the last command is an attempt to remember something about the serialness, but it is still insufficient in some cases. It expands this at parse time into something like CREATE SEQUENCE test_old_id_seq ĪLTER COLUMN id SET DEFAULT nextval('test_old_id_seq') ĪLTER SEQUENCE test_old_id_seq OWNED BY test_old.id PermissionsĪ general problem with the old way is that the system doesn’t actually remember that the user typed serial. So now you can move code around between, for example, PostgreSQL, DB2, and Oracle without any change (in this area). Some have lately been adopting the standard SQL syntax, however. Creating auto-incrementing columns has been a notorious area of incompatibility between different SQL implementations. The new syntax conforms to the SQL standard. INSERT INTO test_new (payload) VALUES ('a'), ('b'), ('c') RETURNING * ĭo pretty much the same thing, except that the new way is more verbose. Id int GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY, INSERT INTO test_old (payload) VALUES ('a'), ('b'), ('c') RETURNING * Depesz already wrote a blog post about it and showed that it works pretty much like serial columns: CREATE TABLE test_old ( In this tutorial, you learned how to rename a table by using the PostgreSQL RENAME table clause of the ALTER TABLE statement.For PostgreSQL 10, I have worked on a feature called “identity columns”. The output shows that the supplier_groups table in the SELECT statement of the view was also updated to groups table. The following statement shows the supplier_data view: \d+ supplier_data You can verify the foreign key constraint in the suppliers table by describing the suppliers table as follows: \d suppliersĪs you can see clearly from the output, the foreign key constraint was updated and referenced the groups table instead. Now, you can rename the supplier_groups table to groups as follows: ALTER TABLE supplier_groups RENAME TO groups Code language: SQL (Structured Query Language) ( sql ) The output shows that the suppliers table has a foreign key constraint which references the supplier_groups table. Let’s check the suppliers table first: \d suppliers When you rename a table to the new one, PostgreSQL will automatically update its dependent objects such as foreign key constraints, views, and indexes. INNER JOIN supplier_groups g ON g.id = s.group_id To save time querying the complete supplier data, you can create a view against the suppliers and supplier_groups tables like this: CREATE VIEW supplier_data This column is the foreign key column that links to the id column of the supplier_groups table: ALTER TABLE suppliersĪDD FOREIGN KEY ( group_id) REFERENCES supplier_groups ( id) You also need to add a new column to the suppliers table named group_id. To manage this relationship, you need to add the supplier_groups table as follows: CREATE TABLE supplier_groups ( Suppose each vendor or supplier belongs to a group. To rename the vendors table to suppliers, you use the following ALTER TABLE RENAME TO statement: ALTER TABLE vendors RENAME TO suppliers Code language: SQL (Structured Query Language) ( sql ) The following statement creates a new table named vendors : DROP TABLE IF EXISTS vendors Ĭode language: SQL (Structured Query Language) ( sql ) It’s not possible to rename multiple taable using a singe ALTER TABLE statement. To rename multiple tables, you have to execute multiple ALTER TABLE RENAME TO statements. In this case, if the table_name does not exist, PostgreSQL will issue a notice instead. ![]() ![]() To avoid this, you add the IF EXISTS option as follows: ALTER TABLE IF EXISTS table_name If you try to rename a table that does not exist, PostgreSQL will issue an error. Second, give the new table name after the RENAME TO clause.First, specify the name of the table which you want to rename after the ALTER TABLE clause.RENAME TO new_table_name Code language: SQL (Structured Query Language) ( sql ) To rename an existing table, you use the ALTER TABLE statement as follows: ALTER TABLE table_name Overview of PostgreSQL rename table statement Summary: this tutorial shows you how to rename a table by using the PostgreSQL RENAME table clause of the ALTER TABLE statement. ![]()
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