结合 INSERT 和 CASE SQL Server 查询

Question

这里有几个 SQL 查询，我尝试将它们编写为单个查询或两个查询。我尝试了各种我能想到但没有奏效的可能性。

我有一张空白表tbl_Z。我正在尝试 LEFT JOIN tbl_A 和 tbl_B 并将结果加载到 tbl_Z 并根据此处显示的 2 个 SQL 语句中的条件从 tbl_A 更新 tbl_Z 中的 Status 列：

INSERT INTO tbl_Z
    SELECT a.*
    FROM tbl_A a
    LEFT JOIN tbl_B b ON a.AccountNumber = b.AccountNumber
    WHERE a.Period = '09/30/2021'
      AND b.AccountNumber IS NULL

UPDATE Z
SET Status = (SELECT 
                  f.ContractDate, f.BK_Date, f.Period,
                  CASE
                      WHEN ISNULL(f.ContractDate, '1/1/1900') < ISNULL(f.BK_Date, '1/1/1900') AND f.BK_Date < ISNULL(f.Period, '1/1/1900') 
                          THEN 'Bankrupt.Attrit'
                          ELSE 'Attrit'
                  END AS Status
              FROM 
                  tbl_A f
              WHERE 
                  Period = '09/30/2021')

任何帮助将不胜感激。

Answer 1

我不知道字段名称，只是在select中添加字段名称，将case语句按字段的写入顺序。

INSERT INTO tbl_Z
    SELECT -- please write your all tbl_A fields here and then place below case in write order of selection
            , 
               CASE
                 WHEN ISNULL(f.ContractDate, '1/1/1900') < ISNULL(f.BK_Date, '1/1/1900') 
                      AND f.BK_Date < ISNULL(f.Period, '1/1/1900') 
                       THEN 'Bankrupt.Attrit'
                 ELSE 'Attrit'
                 END AS Status
    FROM tbl_A a
    LEFT JOIN tbl_B b ON a.AccountNumber = b.AccountNumber
    WHERE a.Period = '09/30/2021'
      AND b.AccountNumber IS NULL;