Postgresql查询库结构及表属性SQL总结

库结构（用户、表、序列、视图、触发器、物化视图）

• 【用户】 查询 数据库中的所有用户

-- 查询所有用户
select * from pg_user;
-- 查询当前用户
select * from current_user;

• 【编码格式】查询 所有数据库字符编码

show server_encoding

• 【模式】查询 数据库所有模式

SELECT schema_name FROM information_schema.schemata where schema_name not in 
  ('pg_toast','pg_temp_1','pg_toast_temp_1','pg_catalog','information_schema')

• 【表】根据模式名 查询所有表

SELECT schemaname,tablename FROM pg_tables where schemaname='模式名'

• 【序列】 查询 序列

SELECT sequencename FROM pg_sequences WHERE schemaname = '模式名'

• 【视图】根据用户名 查询所有视图

SELECT viewname FROM pg_views WHERE schemaname= '模式名'

• 【触发器】根据用户名 查询所有触发器

SELECT TRIGGER_NAME,event_object_table,action_statement FROM information_schema.TRIGGERS  
 WHERE TRIGGER_SCHEMA='模式名'

• 【物化视图】根据用户名 查询所有物化视图

select matviewname from pg_matviews WHERE schemaname ='模式名'

表属性（字段、主键、外键、索引、唯一约束）

• 【字段】根据表名 查询 列属性

-- 查询字段属性
select ordinal_position column_id,COLUMN_NAME,DATA_TYPE,CHARACTER_MAXIMUM_LENGTH data_length,
  IS_NULLABLE nullable,null pk_column
  from information_schema.columns where table_schema='模式名' and table_name='表名'

-- 查询字段注释
SELECT c.relname as tablename ,a.attname as cols,col_description(a.attrelid,a.attnum) 
  FROM pg_class as c,pg_attribute as a ,pg_tables as b 
  where a.attrelid = c.oid and a.attnum>0 and c.relname=b.tablename 
  and b.schemaname='模式名' and c.relname = '表名'

• 【主键】根据表名 查询 主键

SELECT distinct kcu.column_name FROM information_schema.table_constraints AS tc  
  JOIN information_schema.key_column_usage AS kcu ON tc.constraint_name = kcu.constraint_name
  WHERE constraint_type = 'PRIMARY KEY' 
  AND tc.table_name = '表名' and tc.constraint_schema='模式名'

• 【外键】根据表名 查询 外键 及 外键关联的详细信息

SELECT  tc.constraint_name, tc.table_name, kcu.column_name, 
  ccu.table_name AS foreign_table_name,ccu.column_name AS foreign_column_name
  FROM  information_schema.table_constraints AS tc 
  JOIN information_schema.key_column_usage AS kcu ON tc.constraint_name = kcu.constraint_name 
  JOIN information_schema.constraint_column_usage AS ccu ON ccu.constraint_name = tc.constraint_name
  WHERE constraint_type = 'FOREIGN KEY' 
  AND tc.table_name = '表名' and tc.constraint_schema='模式名'

• 【索引】根据表名 查询 索引

select indexname,indexdef from pg_indexes 
  where tablename='表名' and schemaname = '模式名' 
  and indexname not in(SELECT distinct constraint_name FROM information_schema.table_constraints 
  WHERE table_name = '表名' and constraint_schema='模式名')

• 【唯一约束】根据表名 查询 唯一约束

 SELECT distinct tc.constraint_name,kcu.column_name FROM information_schema.table_constraints AS tc  
   JOIN information_schema.key_column_usage AS kcu ON tc.constraint_name = kcu.constraint_name
   WHERE constraint_type = 'UNIQUE' 
   AND tc.table_name = '表名' and tc.constraint_schema='模式名'