Question

下面我使用OUTPUT参数输出更新语句：

    UPDATE set Value = src.Value, DeletedDate = iif (@Deleted =1, getutcdate(), NULL), ModifiedBy = SUSER_SNAME(), ModifiedDate = getutcdate()
WHEN NOT MATCHED THEN
    INSERT (ConfigKey, Value, AddedBy, ModifiedBy)
    VALUES (@ConfigKey, @Value, SUSER_SNAME(), SUSER_SNAME())
OUTPUT 'Core.Config', 'ConfigID', inserted.ConfigID,
    iif($action = 'Update',  Core.updXMLFragment('Value', inserted.Value, deleted.Value)+
                             Core.updXMLFragment('ModifiedBy', inserted.ModifiedBy, deleted.ModifiedBy) +                                   
                             Core.updXMLFragment('DeletedDate', inserted.DeletedDate, deleted.DeletedDate)

                          ,  Core.insXMLFragment('ConfigID') + 
                             Core.addnlXMLFragment ('ModifiedBy', inserted.ModifiedBy))

上面的代码在底部生成更新语句，但我在更新语句中遇到的问题是'DeletedDate = 0'。我需要将其更改为DeletedDate=NULL并且条件为'DeletedDate IS NULL'。怎么办呢？

BEGIN TRAN
update Core.Config
                set Value = 'Insert',ModifiedBy = 'HARROGATE\Name' ,DeletedDate = '0'
                where ConfigID = '1' and Value = 'Update' and ModifiedBy = 'HARROGATE\Name' and DeletedDate = '0'
                if @@ROWCOUNT <> 1 
                    BEGIN;
                        THROW 99999, 'Error - Single Row not updated, rollback terminated', 1;
                    END;

更新：包含updxmlfragment

BEGIN


if (@InsertedValue = '')
BEGIN
set @InsertedValue = ' ' 
END
if(@DeletedValue = '')
BEGIN
set @DeletedValue = ' '
END

if(@FieldName IS NULL)
--if(@InsertedValue IS NULL and @DeletedValue IS NULL or @FieldName IS NULL) -- pre v2.1 logic
BEGIN

-- This "errors" the function and ensures the script doesn't get any further than the update
return convert(int, 'NULL Params passed for XML Fragment Generation')

END

-- Validate the date has the correct "time" element associated - i.e HH:MM:SS:MSS
if (@FieldName like '%date%')
BEGIN

if((TRY_PARSE(@InsertedValue as datetime) IS NOT NULL) or (TRY_PARSE(@DeletedValue as datetime) IS NOT NULL))
BEGIN
if((len(replace(@DeletedValue, ':', '')) +3 <> len(@deletedvalue)) OR (len(replace(@InsertedValue, ':', '')) +3 <> len(@InsertedValue)))
BEGIN
-- This "errors" the function and ensures the script doesn't get any further than the update
return convert(datetime, 'Invalid Date Params passed for XML Fragment Generation')
END
END
END

return 
'<Update><FieldName>'+@FieldName+'</FieldName>'+iif(@DeletedValue is null, '<OldValue />',  '<OldValue><![CDATA['+@DeletedValue+']]></OldValue>') 
+iif(@InsertedValue is null, '<NewValue />',  '<NewValue><![CDATA['+@InsertedValue+']]></NewValue>') + '</Update>

'

Answer 1

为什么不使用NULLIF()？

如果两个指定的表达式相等，则返回null值。

因此，您必须仅使用NULLIF(DeletedDate, 0)代替DeletedDate。

更新

根据我的理解，你必须像这样使用它：

UPDATE
SET Value = src.Value
  , DeletedDate = IIF(@Deleted = 1, getutcdate(), NULL)
  , ModifiedBy = SUSER_SNAME()
  , ModifiedDate = getutcdate() WHEN NOT MATCHED THEN
INSERT (ConfigKey, Value, AddedBy, ModifiedBy)
VALUES (@ConfigKey, @Value, SUSER_SNAME(), SUSER_SNAME())
OUTPUT 'Core.Config'
  , 'ConfigID'
  , inserted.ConfigID
  , IIF($ACTION = 'Update', Core.updXMLFragment('Value', inserted.Value, deleted.Value) + Core.updXMLFragment('ModifiedBy', inserted.ModifiedBy, deleted.ModifiedBy) + Core.updXMLFragment('DeletedDate', NULLIF(inserted.DeletedDate, 0), NULLIF(deleted.DeletedDate, 0))
  , Core.insXMLFragment('ConfigID') + Core.addnlXMLFragment('ModifiedBy', inserted.ModifiedBy))

UPDATE Core.Config
SET Value = 'Insert'
  , ModifiedBy = 'HARROGATE\Name'
  , DeletedDate = NULL
WHERE ConfigID = '1'
  AND Value = 'Update'
  AND ModifiedBy = 'HARROGATE\Name'
  AND NULLIF(DeletedDate, 0) IS NULL;

如何将= 0更改为IS NULL

1 个答案:

更新