Error: has incompatible types: sql.NullString, interface{}

[omid9h]

I have a MySQL query with multiple named parameters. everything is fine but for bellow chunk:

AND (
    sqlc.narg(phone_filter) IS NULL
    OR (
        (
            length (sqlc.narg(phone_filter)) != 11
            OR aes_decrypt (from_base64 (u.phone), sqlc.arg(aes_key)) = sqlc.narg(phone_filter)
        )
        AND (
            length (sqlc.narg(phone_filter)) = 11
            OR aes_decrypt (from_base64 (u.phone), sqlc.arg(aes_key)) LIKE '%' || sqlc.narg(phone_filter) || '%'
        )
    )
)

and for the last line OR aes_decrypt (from_base64 (u.phone), sqlc.arg(aes_key)) LIKE '%' || sqlc.narg(phone_filter) || '%'

I get this error:

# package demorepo error generating code: named param PhoneFilter has incompatible types: sql.NullString, interface{}

any idea how to fix this? thanks