// Copyright 2022 RisingWave Labs
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use risingwave_common::types::Fields;
use risingwave_frontend_macro::system_catalog;

/// The catalog `pg_attrdef` stores column default values. The main information about columns is
/// stored in `pg_attribute`. Only columns for which a default value has been explicitly set will
/// have an entry here. Ref: `https://www.postgresql.org/docs/current/catalog-pg-attrdef.html`
#[system_catalog(view, "pg_catalog.pg_attrdef")]
#[derive(Fields)]
struct PgAttrdef {
    oid: i32,
    adrelid: i32,
    adnum: i16,
    // The column default value, use pg_get_expr(adbin, adrelid) to convert it to an SQL
    // expression. We don't have `pg_node_tree` type yet, so we use `text` instead.
    adbin: String,
}
