连接pg的jdbc的url格式：jdbc:postgresql://ip:port/dbname
查看指定库的所有表和视图信息
--法一：查询当前登录url所在可下public的
SELECT a.oid,
a.relname AS name,
b.description AS comment
FROM pg_class a
LEFT OUTER JOIN pg_description b ON b.objsubid=0 AND a.oid = b.objoid
WHERE a.relnamespace = (SELECT oid FROM pg_namespace WHERE nspname='public') --用户表一般存储在public模式下
AND a.relkind='r'
ORDER BY a.relname;
--表信息
select * from pg_tables where schemaname='public' and tableowner='db_name';
--视图的定义
select definition from pg_views where viewname='xxxx' and viewowner='xxxxx';
查看表的建表信息
--法一
SELECT a.attnum,
a.attname AS field,
t.typname AS type,
a.attlen AS length,
a.atttypmod AS lengthvar,
a.attnotnull AS notnull,
b.description AS comment
FROM pg_class c,
pg_attribute a
LEFT OUTER JOIN pg_description b ON a.attrelid=b.objoid AND a.attnum = b.objsubid,
pg_type t
WHERE c.relname = 'xxxxxx'
and a.attnum > 0
and a.attrelid = c.oid
and a.atttypid = t.oid
ORDER BY a.attnum;
--法二
select
col.table_schema,
col.table_name,
col.ordinal_position,
col.column_name,
col.data_type,
col.character_maximum_length,
col.numeric_precision,
col.numeric_scale,
col.is_nullable,
col.column_default,
des.description
from
information_schema.columns col left join pg_description des on
col.table_name::regclass = des.objoid
and col.ordinal_position = des.objsubid
where
table_schema = 'public'
and table_name = 'xxxxxx'
order by
ordinal_position;
生成表的建表语句
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;