PostgreSQL query to rename and change column type with single query

Question

In PostgreSQL if I need to rename and change a column data type, I run two separate queries to do so.

To rename:

ALTER TABLE tblName RENAME <oldColumn> TO <newColumn>  

and to change column type:

ALTER TABLE tblName ALTER COLUMN <newColumn> <columnType>. 

But is there any way to do both of these works with a single query like the following MySQL query:

ALTER TABLE tblName CHANGE COLUMN <oldColumn> <newColumn> <columnType> 

Answer 1

In PostgreSQL, ALTER TABLE can take a series of operations. So:

ALTER TABLE <tablename> RENAME <oldcolumn> TO <newcolumn>; ALTER TABLE <tablename> ALTER COLUMN <columnname> TYPE <newtype>; 

is the same as

ALTER TABLE <tablename>    ALTER COLUMN <columnname> TYPE <newtype>   RENAME <oldcolumn> TO <newcolumn>; 

However... why? IIRC the rename won't cause a full-table scan, so there's no benefit over just doing the two statements separately, within one transaction. What problem are you actually trying to solve with this?

Answer 2

PostgreSQL: Alter table column name and data-type:

ALTER TABLE <TableName>     ALTER [ COLUMN ] column [ SET DATA ] TYPE data_type [ COLLATE collation ] [ USING expression ]   RENAME [ COLUMN ] column TO new_column; 

See ALTER TABLE.