如何检查不同表中两列的内容是否相同？

Question

我的 SQL 数据库中有两个 table。我想检查 Specifier 列是否以完全相同的顺序具有完全相同的数据。

OK case，因为两个 table 在 Specifier 列中具有相同顺序的相同数据：

-- Table1:
RowID   Specifier
187     1         
188     1         
189     2         

-- Table2:
RowID   Specifier
181     1         
182     1         
183     2

错误案例，因为数据不同：

-- Table1:
RowID   Specifier
187     1         
188     2         
189     3         

-- Table2:
RowID   Specifier
181     1         
182     2         
183     2

错误案例，因为数据的顺序不同：

-- Table1:
RowID   Specifier
187     1         
188     1         
189     2         

-- Table2:
RowID   Specifier
181     1         
182     2         
183     1

错误案例，因为数据量不同：

-- Table1:
RowID   Specifier
187     1         
188     1         
189     2         

-- Table2:
RowID   Specifier
181     1         
182     1         
183     2
184     1

我写了下面的查询，它几乎可以工作，如果一个 table 有一个值而另一个没有，它会正确地给出一个错误，但是如果只有订单是不正确：

IF EXISTS
    (SELECT Specifier FROM Table1 EXCEPT SELECT Specifier FROM Table2
    UNION ALL
    SELECT Specifier FROM Table2 EXCEPT SELECT Specifier FROM Table1)
BEGIN
    THROW 99999, 'Mismatching Specifiers between the two tables', 1;
END;

Answer 1

似乎

可能更容易

IF EXISTS (SELECT 1
           FROM (SELECT ROW_NUMBER() OVER (ORDER BY RowID) AS RN,
                        Specifier
                 FROM Table1) T1
                FULL OUTER JOIN (SELECT ROW_NUMBER() OVER (ORDER BY RowID) AS RN,
                                        Specifier
                                 FROM Table2) T2 ON T1.RN = T2.RN
                                                AND T1.Specifier = T2.Specifier
           HAVING COUNT(CASE WHEN T1.RN IS NULL OR T2.RN IS NULL THEN 1 END) >= 1) ...

Answer 2

您可以使用 full join 和 row_number()。以下获取异常：

select *
from (select t1.*, row_number() over (order by rowid) as seqnum
      from table1 t1
     ) t1 full join
     (select t2.*, row_number() over (order by rowid) as seqnum
      from table2 t2
     ) t2
     on t1.seqnum = t2.seqnum and t1.specifier = t2.specifier
where t1.seqnum is null or t2.seqnum is null;

如果您只是想要一面旗帜：

select (case when count(*) > 1 then 1 else 0 end)
from (select t1.*, row_number() over (order by rowid) as seqnum
      from table1 t1
     ) t1 full join
     (select t2.*, row_number() over (order by rowid) as seqnum
      from table2 t2
     ) t2
     on t1.seqnum = t2.seqnum and t1.specifier = t2.specifier
where t1.seqnum is null or t2.seqnum is null;

如果您关心性能，使用带有 exists 的第一个查询应该会更快。

如何检查不同表中两列的内容是否相同？

How to check if the contents of two columns from different tables are identical?

sql

tsql

sql-server

sql-server-2016