PostgreSQL - 查詢表結構和索引信息

前言

PostgreSQL的表通常都是創建在public這個schema下的，假如如今有個數據表t_student，能夠用如下幾種方式來查詢表結構和索引信息。

使用\d元命令查看錶字段信息和索引信息

在cmd界面使用psql鏈接db後，輸入\d加上表名便可：

\d t_student

經過系統數據字典查詢表結構

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 = 't_student'
order by
ordinal_position;

或者簡單點：

select * from information_schema.columns
where table_schema='public' and table_name='t_student';

經過系統數據字典查詢索引信息

select
A.SCHEMANAME,
A.TABLENAME,
A.INDEXNAME,
A.TABLESPACE,
A.INDEXDEF,
B.AMNAME,
C.INDEXRELID,
C.INDNATTS,
C.INDISUNIQUE,
C.INDISPRIMARY,
C.INDISCLUSTERED,
D.DESCRIPTION
from
PG_AM B left join PG_CLASS F on
B.OID = F.RELAM left join PG_STAT_ALL_INDEXES E on
F.OID = E.INDEXRELID left join PG_INDEX C on
E.INDEXRELID = C.INDEXRELID left outer join PG_DESCRIPTION D on
C.INDEXRELID = D.OBJOID,
PG_INDEXES A
where
A.SCHEMANAME = E.SCHEMANAME
and A.TABLENAME = E.RELNAME
and A.INDEXNAME = E.INDEXRELNAME
and E.SCHEMANAME = 'public'
and E.RELNAME = 't_student';

查詢全部的表名

select
n.nspname,
relname
from
pg_class c,
pg_namespace n
where
c.relnamespace = n.oid
and nspname = 'public'
and relkind = 'r'
order by
relname;

可視化工具DBeaver

對於上述的sql語句只須要修改要查詢的table name，能夠根據須要自行修改想要查詢的column。若是是經過DBeaver來鏈接數據庫，還能夠直接在當前的數據庫實例下打開schema裏的public選項，接着選中table，選中你想查看的表，能夠很直觀地看到該表的各類信息：column、index等等。

參考連接

• PostgreSQL：如何查詢表的字段信息？