原作者：范计杰
概述
介绍一些常用的获取MogDB/openGauss对象DDL语句的方法。
内置函数获取DDL
omm2=# \df *def
List of functions
Schema | Name | Result data type | Argument data types | Type | fencedmode | propackage | prokind
------------+----------------------+------------------+----------------------------------------------------------+--------+------------+------------+---------
pg_catalog | pg_get_constraintdef | text | oid | normal | f | f | f
pg_catalog | pg_get_constraintdef | text | oid, boolean | normal | f | f | f
pg_catalog | pg_get_functiondef | record | funcid oid, OUT headerlines integer, OUT definition text | normal | f | f | f
pg_catalog | pg_get_indexdef | text | oid | normal | f | f | f
pg_catalog | pg_get_indexdef | text | oid, boolean | normal | f | f | f
pg_catalog | pg_get_indexdef | text | oid, integer, boolean | normal | f | f | f
pg_catalog | pg_get_ruledef | text | oid | normal | f | f | f
pg_catalog | pg_get_ruledef | text | oid, boolean | normal | f | f | f
pg_catalog | pg_get_tabledef | text | regclass | normal | f | f | f
pg_catalog | pg_get_triggerdef | text | oid | normal | f | f | f
pg_catalog | pg_get_triggerdef | text | oid, boolean | normal | f | f | f
pg_catalog | pg_get_viewdef | text | oid | normal | f | f | f
pg_catalog | pg_get_viewdef | text | oid, boolean | normal | f | f | f
pg_catalog | pg_get_viewdef | text | oid, integer | normal | f | f | f
pg_catalog | pg_get_viewdef | text | text | normal | f | f | f
pg_catalog | pg_get_viewdef | text | text, boolean | normal | f | f | f
(16 rows)
示例
获取表的DDL
omm2=# select pg_get_tabledef('t');
pg_get_tabledef
--------------------------------------------------------
SET search_path = public; +
CREATE TABLE t ( +
id numeric, +
c character varying(100) +
) +
WITH (orientation=row, fillfactor=50, compression=no);
(1 row)
omm2=# \x
Expanded display is on.
omm2=# select pg_get_tabledef('t');
-[ RECORD 1 ]---+-------------------------------------------------------
pg_get_tabledef | SET search_path = public;
| CREATE TABLE t (
| id numeric,
| c character varying(100)
| )
| WITH (orientation=row, fillfactor=50, compression=no);
获取索引DDL
omm2=# select pg_get_indexdef('idx_t_id'::regclass);
pg_get_indexdef
-------------------------------------------------------------------
CREATE INDEX idx_t_id ON t USING btree (id) TABLESPACE pg_default
(1 row)
部分视图中直接提供了DDL
omm2=# \x
Expanded display is on.
omm2=# select * from pg_indexes where indexname='idx_t_id';
-[ RECORD 1 ]-----------------------------------------------------------------
schemaname | public
tablename | t
indexname | idx_t_id
tablespace |
indexdef | CREATE INDEX idx_t_id ON t USING btree (id) TABLESPACE pg_default
通过gs_dump生成ddl
这样还可以生成表及表上的索引定义等
$ gs_dump -t t --section pre-data omm2
SET statement_timeout = 0;
SET xmloption = content;
SET client_encoding = 'UTF8';
SET standard_conforming_strings = on;
SET check_function_bodies = false;
SET client_min_messages = warning;
SET search_path = public;
SET default_tablespace = '';
SET default_with_oids = false;
--
-- Name: t; Type: TABLE; Schema: public; Owner: omm2; Tablespace:
--
CREATE TABLE t (
id numeric,
c character varying(100)
)
WITH (orientation=row, fillfactor=50, compression=no);
ALTER TABLE public.t OWNER TO omm2;
$ gs_dump -t t --section post-data omm2
SET statement_timeout = 0;
SET xmloption = content;
SET client_encoding = 'UTF8';
SET standard_conforming_strings = on;
SET check_function_bodies = false;
SET client_min_messages = warning;
SET search_path = public;
SET default_tablespace = '';
--
-- Name: idx_t_id; Type: INDEX; Schema: public; Owner: omm2; Tablespace:
--
CREATE INDEX idx_t_id ON t USING btree (id) TABLESPACE pg_default;
