Granting user access to specific columns

A user can be given access to only some table columns.

Getting ready

We will continue the example from the previous recipe, so we assume that there is already a schema called someschema and a role called somerole with USAGE privileges on it. We create a new table on which we will grant column-level privileges:

CREATE TABLE someschema.sometable2(col1 int, col2 text);

How to do it…

1. We want to grant somerole the ability to view existing data and insert new data; we also want to provide the ability to amend existing data, limited to column col2 only. We use the following self-evident statements:

GRANT SELECT, INSERT ON someschema.sometable2 TO somerole; 
GRANT UPDATE (col2) ON someschema.sometable2 TO somerole;

2. Let's assume the identity of the somerolerole and test these privileges with the following commands:

SET ROLE TO somerole; 
INSERT INTO someschema.sometable2 VALUES (1, 'One'); 
SELECT * FROM someschema.sometable2 WHERE col1 = 1;

3. As expected, we are able...