从两个不同的表中获取数据，这些表在 sql server 中只有一个公共列

Question

My tables are as follows:

Please give me an SQL query to get the expected result set.

Table1                  
A   B   C   D   E   
1   2   C1  D1  E1  
2   2   C2  D2  E2  
3   2   C3  D3  E3  


Table2                  
A   B   F   G   H   
1   2   F1  G1  H1  
2   2   F2  G2  H2  
3   5   F3  G3  H3  
4   6   F4  G4  H4  

Expected Result :

B   C       D       E       F       G       H
2   C1      D1      E1      NULL    NULL    NULL
2   C2      D2      E2      NULL    NULL    NULL
2   C3      D3      E3      NULL    NULL    NULL
2   NULL    NULL    NULL    F1      G1      H1
2   NULL    NULL    NULL    F2      G2      H2

Answer 1

You need UNION to combine results of two or more queries as below. As you have C, D, E in one table and they are not present in another you need to add this columns with NULL values, the same to F, G, H :

SELECT *
FROM (
    SELECT  B,   
            C,   
            D,   
            E, 
            NULL F, 
            NULL G, 
            NULL H  
    FROM Table1 t1
    UNION
    SELECT  B,  
            NULL C,
            NULL D, 
            NULL E,  
            F,   
            G,   
            H  
    FROM Table2 t2
) t
WHERE B = 2

Output:

B   C       D       E       F       G       H
2   C1      D1      E1      NULL    NULL    NULL
2   C2      D2      E2      NULL    NULL    NULL
2   C3      D3      E3      NULL    NULL    NULL
2   NULL    NULL    NULL    F1      G1      H1
2   NULL    NULL    NULL    F2      G2      H2