postgresql 查询字段 信息

SELECT

base."column_name",

col_description ( t1.oid, t2.attnum ),

base.udt_name,

COALESCE(character_maximum_length, numeric_precision, datetime_precision),

(CASE

WHEN ( SELECT t2.attnum = ANY ( conkey ) FROM pg_constraint WHERE conrelid = t1.oid AND contype = 'p' ) = 't'

THEN 1 ELSE 0

END )

FROM

information_schema.COLUMNS base,

pg_class t1,

pg_attribute t2

WHERE

base."table_name" = 'sys_org'

AND t1.relname = base."table_name"

AND t2.attname = base."column_name"

AND t1.oid = t2.attrelid

AND t2.attnum > 0;

以上查询的是'sys_org'表的字段信息，下面对各个属性进行解释。