postgresql 實現獲取所有表名,字段名,字段類型,註釋

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獲取表名及註釋：

select relname as tabname,cast(obj_description(relfilenode,'pg_class') as varchar) as comment from pg_class c 
where relkind = 'r' and relname not like 'pg_%' and relname not like 'sql_%' order by relname

過濾掉分表：

加條件 and relchecks=0 即可

獲取字段名、類型、註釋、是否為空：

SELECT col_description(a.attrelid,a.attnum) as comment,format_type(a.atttypid,a.atttypmod) as type,a.attname as name, a.attnotnull as notnull 
FROM pg_class as c,pg_attribute as a where c.relname = '表名' and a.attrelid = c.oid and a.attnum>0

補充：PostgreSQL查詢表主鍵及註釋內容

網上關於pgSql獲取表主鍵的內容都是千篇一律，並且對於存在多主鍵的場景不支持。

附上測試後可獲取多個主鍵字段值的SQL

SELECT
 string_agg(DISTINCT t3.attname,',') AS primaryKeyColumn
 ,t4.tablename AS tableName
 , string_agg(cast(obj_description(relfilenode,'pg_class') as varchar),'') as comment
FROM
 pg_constraint t1
 INNER JOIN pg_class t2 ON t1.conrelid = t2.oid
 INNER JOIN pg_attribute t3 ON t3.attrelid = t2.oid AND array_position(t1.conkey,t3.attnum) is not null
 INNER JOIN pg_tables t4 on t4.tablename = t2.relname
 INNER JOIN pg_index t5 ON t5.indrelid = t2.oid AND t3.attnum = ANY (t5.indkey)
 LEFT JOIN pg_description t6 on t6.objoid=t3.attrelid and t6.objsubid=t3.attnum
WHERE t1.contype = 'p'
  AND length(t3.attname) > 0
  AND t2.oid = '表名' :: regclass
 group by t4.tablename

目前隻找到瞭獲取指定表的主鍵信息，對於批量獲取沒有找到。

以上為個人經驗，希望能給大傢一個參考，也希望大傢多多支持WalkonNet。如有錯誤或未考慮完全的地方，望不吝賜教。

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