Sql 合并无键联接的表数据

我在MS Sql Server数据库中有两个表，它们是从不同来源导入的，我想合并它们

表1： 表1数据： 表2： 表2数据： 我想用表2的代码字段中的值更新表1的代码字段。两个表都有相同数量的记录，表2中的哪个代码进入表1中的哪个记录并不重要，但表1中的每个记录都必须有一个来自表2的唯一代码（表2中的每个代码值都是唯一的）

通常情况下，两个表中都会有一个Id，我可以加入其中，但这里不是这样，Table1 Id不是连续的（一些记录已被删除）

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唯一的方法是一行一行地循环记录吗

将行号添加到基表中并在此基础上加入。下面的代码可以工作

update t1
set t1.code = t2.code
from
(select *, row_number() over(order by id) as rNum1  from table1) t1
join 
(select *, row_number() over(order by code) as rNum2 from table2) t2
on t1.rnum1 = t2.rnum2

---

将行号添加到基表并在此基础上联接。下面的代码可以工作

update t1
set t1.code = t2.code
from
(select *, row_number() over(order by id) as rNum1  from table1) t1
join 
(select *, row_number() over(order by code) as rNum2 from table2) t2
on t1.rnum1 = t2.rnum2

---

如果每个表中的行数相同，并且哪个代码与哪个记录对应并不重要，那么为什么不在子查询中使用行数创建任意键字段，然后在该字段上进行联接呢

SELECT
    TABLE1.ID,
    TABLE1.Name,
    TABLE2.Code

FROM
    (SELECT ROW_NUMBER() OVER (ORDER BY ID) AS 'Key_Field', ID, Name, Code FROM Table1) TABLE1

    LEFT OUTER JOIN
    (SELECT ROW_NUMBER() OVER (ORDER BY Code) AS 'Key_Field', Code FROM Table2) TABLE2
    ON
    TABLE1.Key_Field = TABLE2.Key_Field

---

如果每个表中的行数相同，并且哪个代码与哪个记录对应并不重要，那么为什么不在子查询中使用行数创建任意键字段，然后在该字段上进行联接呢

SELECT
    TABLE1.ID,
    TABLE1.Name,
    TABLE2.Code

FROM
    (SELECT ROW_NUMBER() OVER (ORDER BY ID) AS 'Key_Field', ID, Name, Code FROM Table1) TABLE1

    LEFT OUTER JOIN
    (SELECT ROW_NUMBER() OVER (ORDER BY Code) AS 'Key_Field', Code FROM Table2) TABLE2
    ON
    TABLE1.Key_Field = TABLE2.Key_Field

---

如果记录数相等，且更新顺序不重要，则可以为两个表中的每条记录指定任意行号，然后进行匹配：

WITH T1 AS
(   SELECT  ID, 
            Code,
            RowNumber = ROW_NUMBER() OVER(ORDER BY (SELECT 1))
    FROM    Table1
), T2 AS
(   SELECT  Code,
            RowNumber = ROW_NUMBER() OVER(ORDER BY (SELECT 1))
    FROM    Table2
)
UPDATE  T1
SET     Code = T2.Code
FROM    T1
        INNER JOIN T2
            ON T1.RowNumber = T2.RowNumber;

---

如果记录数相等，且更新顺序不重要，则可以为两个表中的每条记录指定任意行号，然后进行匹配：

WITH T1 AS
(   SELECT  ID, 
            Code,
            RowNumber = ROW_NUMBER() OVER(ORDER BY (SELECT 1))
    FROM    Table1
), T2 AS
(   SELECT  Code,
            RowNumber = ROW_NUMBER() OVER(ORDER BY (SELECT 1))
    FROM    Table2
)
UPDATE  T1
SET     Code = T2.Code
FROM    T1
        INNER JOIN T2
            ON T1.RowNumber = T2.RowNumber;

WITH T1 AS
(   SELECT  ID, 
            Code,
            RowNumber = ROW_NUMBER() OVER(ORDER BY (SELECT 1))
    FROM    Table1
), T2 AS
(   SELECT  Code,
            RowNumber = ROW_NUMBER() OVER(ORDER BY (SELECT 1))
    FROM    Table2
)
UPDATE  T1
SET     Code = T2.Code
FROM    T1
        INNER JOIN T2
            ON T1.RowNumber = T2.RowNumber;