sql - sql查询从数据库中查找缺少的表

Question

我正在使用 ORACLE 数据库。 编辑：

我只想要列表中不存在的表，而不是数据库中的所有表。

例如：在我的数据库中存在以下表格：

a
b
c
d
e
r
s

我得到了一个表格列表：

a
b
c
v
h

其中我想找出我的数据库中哪些表不存在（不存在）。

所以：a、b、c 是我的数据库中存在的那些表。因此，排除这些表格，我的答案将是：

v and h 

我的答案不是 d,e,r,s

我怎样才能为此编写查询以找出答案？

Answer 1

您可以使用

SELECT a.table_name FROM (SELECT 'A' as table_name 
               FROM DUAL UNION
               SELECT 'B' as table_name 
               FROM DUAL UNION
               SELECT 'C' as table_name 
               FROM DUAL UNION
               SELECT 'V' as table_name 
               FROM DUAL UNION
               SELECT 'H' as table_name 
               FROM DUAL) a WHERE NOT EXISTS (
SELECT 1 FROM DBA_TABLES b where b.table_name=a.table_name)

Answer 2

WITH table_names AS ( 
   SELECT 'A' AS tname FROM DUAL
   UNION ALL
   SELECT 'B' FROM DUAL
   UNION ALL
   SELECT 'C' FROM DUAL
   UNION ALL
   SELECT 'D' FROM DUAL
   UNION ALL
   SELECT 'E' FROM DUAL
)
SELECT tn.tname
FROM table_name tn
WHERE NOT EXISTS (SELECT 1  
                  FROM all_tables at
                  WHERE tn.tname = at.table_name);

WITH 部分只是编写派生表（“内联视图”）的一种不同（可重用）方式。

Answer 3

我会用 MINUS 运算符（总结如下）：

select table_name from table_list
minus
select table_name from db_tables
;

更全面：

with table_list as 
(     select 'A' table_name from dual    
union select 'B' table_name from dual
union select 'C' table_name from dual
union select 'V' table_name from dual
union select 'H' table_name from dual
) 
, db_tables as
(     select 'A' table_name from dual
union select 'B' table_name from dual
union select 'C' table_name from dual
union select 'D' table_name from dual
union select 'E' table_name from dual
union select 'R' table_name from dual
union select 'S' table_name from dual
)
select table_name from table_list
minus
select table_name from db_tables
;

Answer 4

SELECT table_name FROM DBA_tables WHERE table_name IN (Yourlist comes here)

例如

SELECT table_name FROM DBA_tables WHERE table_name NOT IN ('a','b','c');

Answer 5

您可以使用该表和 sys.dbms_debug_vc2coll 从您的列表中创建一个虚拟列。

以下应该可以解决问题：

SELECT
    column_value AS missing_table_names
FROM
    TABLE(SYS.DBMS_DEBUG_VC2COLL('a','b','c','v','h'))
WHERE
    column_value NOT IN (
        SELECT
            table_name
        FROM
            ALL_TABLES
    );