我已经在postgreSQL中创建了一个表。我想查看用于创建表的SQL语句,但无法找出它。
如何通过命令行或SQL语句获得Postgres中现有表的创建表SQL语句?
我已经在postgreSQL中创建了一个表。我想查看用于创建表的SQL语句,但无法找出它。
如何通过命令行或SQL语句获得Postgres中现有表的创建表SQL语句?
当前回答
DataGrip具有与pgAdmin相同的功能。你可以右键点击一个表,你会看到选项自动生成创建表语句。
其他回答
这是对我有用的变化:
pg_dump -U user_viktor -h localhost unit_test_database -t floorplanpreferences_table——schema-only
此外,如果你正在使用模式,你当然也需要指定:
pg_dump -U user_viktor -h localhost unit_test_database -t "949766e0-e81e-11e3-b325-1cc1de32fcb6"。floorplanpreferences_table——模式
您将得到一个输出,可以用来再次创建表,只需在psql中运行该输出。
下面是一条语句,它将为指定模式(包括约束)中的单个表生成DDL。
SELECT 'CREATE TABLE ' || pn.nspname || '.' || pc.relname || E'(\n' ||
string_agg(pa.attname || ' ' || pg_catalog.format_type(pa.atttypid, pa.atttypmod) || coalesce(' DEFAULT ' || (
SELECT pg_catalog.pg_get_expr(d.adbin, d.adrelid)
FROM pg_catalog.pg_attrdef d
WHERE d.adrelid = pa.attrelid
AND d.adnum = pa.attnum
AND pa.atthasdef
),
'') || ' ' ||
CASE pa.attnotnull
WHEN TRUE THEN 'NOT NULL'
ELSE 'NULL'
END, E',\n') ||
coalesce((SELECT E',\n' || string_agg('CONSTRAINT ' || pc1.conname || ' ' || pg_get_constraintdef(pc1.oid), E',\n' ORDER BY pc1.conindid)
FROM pg_constraint pc1
WHERE pc1.conrelid = pa.attrelid), '') ||
E');'
FROM pg_catalog.pg_attribute pa
JOIN pg_catalog.pg_class pc
ON pc.oid = pa.attrelid
AND pc.relname = 'table_name'
JOIN pg_catalog.pg_namespace pn
ON pn.oid = pc.relnamespace
AND pn.nspname = 'schema_name'
WHERE pa.attnum > 0
AND NOT pa.attisdropped
GROUP BY pn.nspname, pc.relname, pa.attrelid;
如果您不想创建函数,而只想让查询创建一个基本的表结构,这里有一个解决方案。
select 'CREATE TABLE ' || table_name ||'(' ||STRING_AGG (
column_name || ' ' || data_type ,
','
ORDER BY
table_name,
ordinal_position
) ||');'
from
information_schema.columns
where table_schema = 'public'
group by
table_name
(注意-此解决方案不适用于PostgreSQL v12+)
我的解决方案是使用psql和-E选项登录postgres db,如下所示:
psql -E -U username -d database
在psql中,运行以下命令查看postgres用来生成的sql 描述表语句:
-- List all tables in the schema (my example schema name is public)
\dt public.*
-- Choose a table name from above
-- For create table of one public.tablename
\d+ public.tablename
基于运行这些描述命令后返回的sql,我能够把它们放在一起 下面是PLPGSQL函数:
CREATE OR REPLACE FUNCTION generate_create_table_statement(p_table_name varchar)
RETURNS text AS
$BODY$
DECLARE
v_table_ddl text;
column_record record;
BEGIN
FOR column_record IN
SELECT
b.nspname as schema_name,
b.relname as table_name,
a.attname as column_name,
pg_catalog.format_type(a.atttypid, a.atttypmod) as column_type,
CASE WHEN
(SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
FROM pg_catalog.pg_attrdef d
WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) IS NOT NULL THEN
'DEFAULT '|| (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)
FROM pg_catalog.pg_attrdef d
WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef)
ELSE
''
END as column_default_value,
CASE WHEN a.attnotnull = true THEN
'NOT NULL'
ELSE
'NULL'
END as column_not_null,
a.attnum as attnum,
e.max_attnum as max_attnum
FROM
pg_catalog.pg_attribute a
INNER JOIN
(SELECT c.oid,
n.nspname,
c.relname
FROM pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relname ~ ('^('||p_table_name||')$')
AND pg_catalog.pg_table_is_visible(c.oid)
ORDER BY 2, 3) b
ON a.attrelid = b.oid
INNER JOIN
(SELECT
a.attrelid,
max(a.attnum) as max_attnum
FROM pg_catalog.pg_attribute a
WHERE a.attnum > 0
AND NOT a.attisdropped
GROUP BY a.attrelid) e
ON a.attrelid=e.attrelid
WHERE a.attnum > 0
AND NOT a.attisdropped
ORDER BY a.attnum
LOOP
IF column_record.attnum = 1 THEN
v_table_ddl:='CREATE TABLE '||column_record.schema_name||'.'||column_record.table_name||' (';
ELSE
v_table_ddl:=v_table_ddl||',';
END IF;
IF column_record.attnum <= column_record.max_attnum THEN
v_table_ddl:=v_table_ddl||chr(10)||
' '||column_record.column_name||' '||column_record.column_type||' '||column_record.column_default_value||' '||column_record.column_not_null;
END IF;
END LOOP;
v_table_ddl:=v_table_ddl||');';
RETURN v_table_ddl;
END;
$BODY$
LANGUAGE 'plpgsql' COST 100.0 SECURITY INVOKER;
下面是函数用法:
SELECT generate_create_table_statement('tablename');
下面是drop语句,如果你不想让这个函数永久保存:
DROP FUNCTION generate_create_table_statement(p_table_name varchar);
使用它并在ddl中获得输出。出文件
~/bin/pg_dump -p 30000 -d <db_name> -U <db_user> --schema=<schema_name> -t <table_name> --schema-only >> /tmp/ddl.out
因此这将在路径:/tmp/ DDL .out中生成DDL