[Known Issue] Database policy support for Create action in PostgreSQL

[ayush3797]

What happened?

Need to support database policies for create action. Something similar to this might be done: #1216.

[ayush3797]

Please go through the issue tagged in description. I hoped that something similar to MsSql would work here as well, but it has its own limitations. Like a query such as this:

INSERT INTO "foo"."magazines" (id, title, issue_number) SELECT "id", "title", "issue_number" FROM (VALUES(800, 'New Magazine', NULL)) T("id", "title", "issue_number") WHERE 1 = 1 RETURNING "id" AS "id", "title" AS "title", "issue_number" AS "issue_number"

fails (I think it fails to determine the type of NULL here) with an exception like column "issue_number" is of type integer but expression is of type text

Equivalent queries that would work here are(notice the datatype being added ahead of NULL/issue_number):

INSERT INTO "foo"."magazines" (id, title, issue_number) SELECT "id", "title", "issue_number"::integer FROM (VALUES(800, 'New Magazine', NULL)) T("id", "title", "issue_number") WHERE 1 = 1 RETURNING "id" AS "id", "title" AS "title", "issue_number" AS "issue_number"
or
INSERT INTO "foo"."magazines" (id, title, issue_number) SELECT "id", "title", "issue_number" FROM (VALUES(800, 'New Magazine', NULL::integer)) T("id", "title", "issue_number") WHERE 1 = 1 RETURNING "id" AS "id", "title" AS "title", "issue_number" AS "issue_number"

I found a stackoverflow article here: https://stackoverflow.com/questions/57750212/postgresql-error-column-qty-is-of-type-integer-but-expression-is-of-type-text which suggests to include datatypes for all the columns in the select clause.
Need to evaluate what would be the best approach to implement database policies for create action for pgsql.