一通过自定义函数查看表的ddl定义

新建函数tabledef

CREATE OR REPLACE FUNCTION tabledef(oid) RETURNS text

LANGUAGE sql STRICT AS $$

WITH attrdef AS (

SELECT

n.nspname,

c.relname,

pg_catalog.array_to_string(c.reloptions || array(select 'toast.' || x from pg_catalog.unnest(tc.reloptions) x), ', ') as relopts,

c.relpersistence,

a.attnum,

a.attname,

pg_catalog.format_type(a.atttypid, a.atttypmod) as atttype,

(SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid, true) for 128) FROM pg_catalog.pg_attrdef d

WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef) as attdefault,

a.attnotnull,

(SELECT c.collname FROM pg_catalog.pg_collation c, pg_catalog.pg_type t

WHERE c.oid = a.attcollation AND t.oid = a.atttypid AND a.attcollation <> t.typcollation) as attcollation,

a.attidentity,

a.attgenerated

FROM pg_catalog.pg_attribute a

JOIN pg_catalog.pg_class c ON a.attrelid = c.oid

JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid

LEFT JOIN pg_catalog.pg_class tc ON (c.reltoastrelid = tc.oid)

WHERE a.attrelid = $1

AND a.attnum > 0

AND NOT a.attisdropped

ORDER BY a.attnum

),

coldef AS (

SELECT

attrdef.nspname,

attrdef.relname,

attrdef.relopts,

attrdef.relpersistence,

pg_catalog.format(

'%I %s%s%s%s%s',

attrdef.attname,

attrdef.atttype,

case when attrdef.attcollation is null then '' else pg_catalog.format(' COLLATE %I', attrdef.attcollation) end,

case when attrdef.attnotnull then ' NOT NULL' else '' end,

case when attrdef.attdefault is null then ''

else case when attrdef.attgenerated = 's' then pg_catalog.format(' GENERATED ALWAYS AS (%s) STORED', attrdef.attdefault)

when attrdef.attgenerated <> '' then ' GENERATED AS NOT_IMPLEMENTED'

else pg_catalog.format(' DEFAULT %s', attrdef.attdefault)

end

end,

case when attrdef.attidentity<>'' then pg_catalog.format(' GENERATED %s AS IDENTITY',

case attrdef.attidentity when 'd' then 'BY DEFAULT' when 'a' then 'ALWAYS' else 'NOT_IMPLEMENTED' end)

else '' end

) as col_create_sql

FROM attrdef

ORDER BY attrdef.attnum

),

tabdef AS (

SELECT

coldef.nspname,

coldef.relname,

coldef.relopts,

coldef.relpersistence,

string_agg(coldef.col_create_sql, E',\n ') as cols_create_sql

FROM coldef

GROUP BY

coldef.nspname, coldef.relname, coldef.relopts, coldef.relpersistence

)

SELECT

format(

'CREATE%s TABLE %I.%I%s%s%s;',

case tabdef.relpersistence when 't' then ' TEMP' when 'u' then ' UNLOGGED' else '' end,

tabdef.nspname,

tabdef.relname,

coalesce(

(SELECT format(E'\n PARTITION OF %I.%I %s\n', pn.nspname, pc.relname,

pg_get_expr(c.relpartbound, c.oid))

FROM pg_class c JOIN pg_inherits i ON c.oid = i.inhrelid

JOIN pg_class pc ON pc.oid = i.inhparent

JOIN pg_namespace pn ON pn.oid = pc.relnamespace

WHERE c.oid = $1),

format(E' (\n %s\n)', tabdef.cols_create_sql)

),

case when tabdef.relopts <> '' then format(' WITH (%s)', tabdef.relopts) else '' end,

coalesce(E'\nPARTITION BY '||pg_get_partkeydef($1), '')

) as table_create_sql

FROM tabdef

$$;

查看表的ddl定义

postgres=# select tabledef('table1'::regclass);

二通过系统函数查看索引的ddl定义

查看索引的ddl定义

使用系统自带的pg_get_indexdef函数查看索引的ddl定义

postgres=# select pg_get_indexdef('table1_pkey'::regclass);

PG数据库如何通过函数查看表和索引的DDL定义

PG数据库如何通过函数查看表和索引的DDL定义

恭喜您！