选择出的信息结果：表名 说明
select user_tab_comments.table_name as 表名,user_tab_comments.comments as 说明 from user_tab_comments
选择出的信息结果：表名（备注）、列名、列标注、主键、外键、字段类型、长度、小数位数、是否允许空、默认值
select
case
when user_tab_comments.comments is null then a.table_name else a.table_name||'('||user_tab_comments.comments||')'
end as 表名（备注）,
a.column_name as 列名,
f.comments as 列标注,
decode(e.key1, 'P', '√', '') as 主键,
decode(e.key2, 'R', '√', '') as 外键,
a.data_type as 字段类型,
NVL(decode(a.data_type, 'NUMBER', a.data_precision, a.data_length),0) as 长度,
NVL(a.data_scale,0) as 小数位数,
a.nullable as 是否为空,
a.data_default as 默认值 from
user_tab_columns a,
user_col_comments f,
user_tab_comments,
( select
uc.table_name,
uc.constraint_name,
ucc.column_name,
uc.constraint_type key1,
uc.constraint_type key2 from
user_constraints uc,
user_cons_columns ucc where
(uc.constraint_type='R'or uc.constraint_type='P')
and uc.constraint_name=ucc.constraint_name
and uc.owner=ucc.owner
and uc.table_name=ucc.table_name
and ucc.table_name not like 'BIN$%==$0'
) e where
a.table_name = e.table_name(+)
and a.column_name = e.column_name(+)
and a.table_name = f.table_name
and a.column_name = f.column_name
and a.table_name = user_tab_comments.table_name
and a.table_name not like 'BIN$%==$0'
order by a.table_name
