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
