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?