Question

我正在尝试在sql server中执行合并更新查询。

表＆＃34; my_table＆＃34;有4列＆＃34;字段＆＃34; （字符），＆＃34;日期＆＃34;（日期），＆＃34; VAL＆＃34;（数字），＆＃34;修订＆＃34;（日期时间）

查询是这样的：

MERGE "my_table" AS Target USING ( VALUES ('field_example','2017-01-04','0','2017-01-03 12:02:02')) AS Source ("field","date","val","revision")
                   ON (Target."field" = Source."field" AND Target."date" = Source."date")
                   WHEN MATCHED 
                   THEN UPDATE SET Target."val" = Source."val",Target."revision" = Source."revision"
                   WHEN NOT MATCHED BY TARGET 
                   THEN INSERT ("field","date","val","revision")
                   VALUES (Source."field", Source."date", Source."val", Source."revision")
                   OUTPUT $action, Inserted.*, Deleted.*;

因为＆＃34; my_table＆＃34; with field =＆＃34; field_example＆＃34;和日期=＆＃39; 2017-01-04＆＃39;，我希望此查询更新其他2列＆＃34; val＆＃34;，＆＃34; revision＆＃34;。

我得到以下查询输出：

$action            field       date            revision val          field.1     date.1          revision.1  val.1
1  UPDATE field_example 2017-01-04 2017-01-03 12:02:02   0 field_example 2017-01-04 2017-01-03 10:09:25 161250

所以它看起来不错（应该更新）

但是当我查看数据库时，该行还没有更新（= val仍然是161250而不是0，修订版仍然是2017-01-03 10:09:25）

知道为什么吗？

Answer 1

然而，当我查看数据库时，该行尚未更新（=   val仍然是161250而不是0，修订仍然是2017-01-03   10时09分25秒）

知道为什么吗？

也许您正在查询不同的表/数据库或者事务已回滚。下面的脚本按预期工作，猜测实际的数据类型。

CREATE TABLE dbo.my_table(
     "field" varchar(100)
     ,"date" date
     ,"val" int
     ,"revision" datetime
     );

INSERT INTO my_table ("field","date","val","revision")
    VALUES ('field_example','2017-01-04','161250','2017-01-03 10:09:25');

MERGE "my_table" AS Target USING ( VALUES ('field_example','2017-01-04','0','2017-01-03 12:02:02')) AS Source ("field","date","val","revision")
    ON (Target."field" = Source."field" AND Target."date" = Source."date")
    WHEN MATCHED THEN
        UPDATE SET Target."val" = Source."val",Target."revision" = Source."revision"
    WHEN NOT MATCHED BY TARGET THEN
        INSERT ("field","date","val","revision")
            VALUES (Source."field", Source."date", Source."val", Source."revision")
    OUTPUT $action, Inserted.*, Deleted.*; 

SELECT "field","date","val","revision" 
FROM my_table;

合并更新查询无法正常执行的问题

1 个答案: