CREATE TABLE foo (bar text not null, maybe_bar text);

-- name: IdentOnNonNullable :many
SELECT bar FROM foo WHERE bar = sqlc.narg(bar);

-- name: IdentOnNullable :many
SELECT maybe_bar FROM foo WHERE maybe_bar = sqlc.narg(maybe_bar);

-- name: StringOnNonNullable :many
SELECT bar FROM foo WHERE bar = sqlc.narg('bar');

-- name: StringOnNullable :many
SELECT maybe_bar FROM foo WHERE maybe_bar = sqlc.narg('maybe_bar');
