合并 2 个表以填充每个表中的缺失记录 - Access / SQL

Question

我有 2 个表，它们具有相同的标题和相同的行数和列数 - 唯一的区别是 Table1 中的记录将在 Table2 中丢失，反之亦然。 因此，如果 Table1 有 50% 的记录，那么 Table2 将有另外 50%。

我想合并这 2 个表以获得完整的 1。我尝试了 JOINS、UNION ALL、UPDATE & INSERT INTO 并且没有工作

UNION ALL is close by 对所有具有“多值字段”的列给出错误，而 UPDATE / INSERT INTO 由于多值字段而给出错误。 INNER JOIN 根本不填空。

表 1

--ID--Header1--Header2--Header3 
   1    app1              org1
   2            lem2       
   3    app3              org3
   4            lem4      

表 2

--ID--Header1--Header2--Header3 
   1            lem1     
   2    app2              org2
   3            lem3       
   4    app4              org4

Answer 1

对于您的示例数据，您可以使用inner join：

select t1.id, nz(t1.header1, t2.header1),
       nz(t1.header2, t2.header2),
       nz(t1.header3, t2.header3)
from table1 t1 inner join
     table2 t2
     on t1.id = t2.id

Answer 2

假设table1 和table2 没有完全匹配的ID 值，并且您希望固定数据出现在table3 中，那么您将需要UNION（而不是@987654326 @) 和LEFT OUTER JOIN，像这样：

INSERT INTO table3( ID, Header1, Header2, Header3 )
SELECT
    u.ID,
    u.Header1,
    u.Header2,
    u.Header3
FROM
    (
        SELECT
            t1.ID,
            IIF( ( t1.Header1 IS NULL OR LEN(t1.Header1) = 0 ) AND t2.Header1 IS NOT NULL, t2.Header1, t1.Header1 ) AS Header1,
            IIF( ( t1.Header2 IS NULL OR LEN(t1.Header2) = 0 ) AND t2.Header2 IS NOT NULL, t2.Header2, t1.Header2 ) AS Header2,
            IIF( ( t1.Header3 IS NULL OR LEN(t1.Header3) = 0 ) AND t2.Header3 IS NOT NULL, t2.Header3, t1.Header3 ) AS Header3
        FROM
            table1 AS t1
            LEFT OUTER JOIN table2 AS t2 ON t1.ID = t2.ID
    
        UNION

        SELECT
            t2.ID,
            IIF( ( t2.Header1 IS NULL OR LEN(t2.Header1) = 0 ) AND t1.Header1 IS NOT NULL, t1.Header1, t2.Header1 ) AS Header1,
            IIF( ( t2.Header2 IS NULL OR LEN(t2.Header2) = 0 ) AND t1.Header2 IS NOT NULL, t1.Header2, t2.Header2 ) AS Header2,
            IIF( ( t2.Header3 IS NULL OR LEN(t2.Header3) = 0 ) AND t1.Header3 IS NOT NULL, t1.Header3, t2.Header3 ) AS Header3
        FROM
            table2 AS t2
            LEFT OUTER JOIN table1 AS t1 ON t1.ID = t2.ID
    ) AS u