如果我查询不存在的记录，那么我将不会返回任何内容。我希望在那种情况下返回0。

本文介绍了如果我查询不存在的记录，那么我将不会返回任何内容。我希望在那种情况下返回0。的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 这是我的简单查询。如果我查询不存在的记录，那么我将不会返回任何内容。我希望在那个场景中返回0。请帮帮我。谢谢。 SELECT * FROM （ SELECT DISTINCT emp.EMP_CODE ，emp.EMP_NAME ，ROW_NUMBER（） OVER （ PARTITION BY \\ temp.emp_code ORDER BY emp.EFFECTIVE_FROM DESC ） AS 行， CASE WHEN et.DAY = @ d1 AND et.MONTH = @ m1 AND et.YEAR = @ y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @ SITE_ID 那么 et.GENERAL_SHIFT ELSE ' 0' END AS G ， CASE WHEN et.DAY = @ d1 AND et.MONTH = @ m1 AND et.YEAR = @ y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @ SITE_ID 那么 et.FIRST_SHIFT ELSE ' 0' END AS F ， CASE WHEN et.DAY = @ d1 AND et.MONTH = @ m1 AND et。 YEAR = @ y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @ SITE_ID 那么 et.SECOND_SHIFT ELSE ' 0' END AS S ， CASE WHEN et.DAY = @ d1 AND et.MONTH = @ m1 AND et.YEAR = @ y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @ SITE_ID 那么 et.THIRD_SHIFT ELSE ' 0' END AS T FROM dbo .EMP_FPONM_EMPLOYEE_INFORMATION emp LEFT JOIN dbo.EMP_FPONM_EMP_TIME_SHEET et ON emp.EMP_CODE = et.EMP_CODE WHERE EMP.SITE_ID = @ SITE_ID AND emp.DEPT_NAME = @ DEPT_NAME AND emp.STATUS = ' Present' AND et.DAY = @ d1 AND et.MONTH = @ m1 AND et.YEAR = @ y1 ）a WHERE a.Row = 1 我是什么尝试过： 如果我查询不存在的记录，那么我将不会返回任何内容。我希望在那个场景中返回0。解决方案 这是我通常在我的表示层中处理的东西，但是如果你必须这样做，那么就有了看一下使用 EXISTS [ ^ ] 例如:(虽然你应该反转这个IF语句） IF NOT EXISTS （ SELECT emp.EMP_CODE FROM dbo。 EMP_FPONM_EMPLOYEE_INFORMATION emp LEFT JOIN dbo.EMP_FPONM_EMP_TIME_SHEET et ON emp.EMP_CODE = et.EMP_CODE WHE RE EMP.SITE_ID = @ SITE_ID AND emp.DEPT_NAME = @ DEPT_NAME AND emp.STATUS = ' Present' AND et.DAY = @ d1 AND et.MONTH = @ m1 AND et.YEAR = @ y1 ） SELECT 0 as EMP_CODE，' ' AS EMP_NAME， 0 AS 行，' 0' AS G，' 0' AS F，' 0' AS S，' 0' AS T ELSE - 此处的原始查询 END 顺便说一句，我真诚地希望您不在varchar字段中存储数值： - ） Here's my simple query. If I query a record that doesn't exist then I will get nothing returned. I'd prefer that 0 is returned in that scenario. Please help me out from this.Thanks in advanceSELECT * FROM ( SELECT DISTINCT emp.EMP_CODE ,emp.EMP_NAME ,ROW_NUMBER() OVER ( PARTITION BY emp.emp_code ORDER BY emp.EFFECTIVE_FROM DESC ) AS Row ,CASE WHEN et.DAY = @d1 AND et.MONTH = @m1 AND et.YEAR = @y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @SITE_ID THEN et.GENERAL_SHIFT ELSE '0' END AS G ,CASE WHEN et.DAY = @d1 AND et.MONTH = @m1 AND et.YEAR = @y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @SITE_ID THEN et.FIRST_SHIFT ELSE '0' END AS F ,CASE WHEN et.DAY = @d1 AND et.MONTH = @m1 AND et.YEAR = @y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @SITE_ID THEN et.SECOND_SHIFT ELSE '0' END AS S ,CASE WHEN et.DAY = @d1 AND et.MONTH = @m1 AND et.YEAR = @y1 AND et.EMP_CODE = emp.EMP_CODE AND et.site_id = @SITE_ID THEN et.THIRD_SHIFT ELSE '0' END AS T FROM dbo.EMP_FPONM_EMPLOYEE_INFORMATION emp LEFT JOIN dbo.EMP_FPONM_EMP_TIME_SHEET et ON emp.EMP_CODE = et.EMP_CODE WHERE EMP.SITE_ID = @SITE_ID AND emp.DEPT_NAME = @DEPT_NAME AND emp.STATUS = 'Present' AND et.DAY = @d1 AND et.MONTH = @m1 AND et.YEAR = @y1 ) a WHERE a.Row = 1What I have tried:If I query a record that doesn't exist then I will get nothing returned. I'd prefer that 0 is returned in that scenario. 解决方案 That's something I would normally handle in my presentation layer but if you must do it this way then have a look at using EXISTS[^]For example: (although you should probably invert this IF statement)IF NOT EXISTS (SELECT emp.EMP_CODE FROM dbo.EMP_FPONM_EMPLOYEE_INFORMATION emp LEFT JOIN dbo.EMP_FPONM_EMP_TIME_SHEET et ON emp.EMP_CODE = et.EMP_CODE WHERE EMP.SITE_ID = @SITE_ID AND emp.DEPT_NAME = @DEPT_NAME AND emp.STATUS = 'Present' AND et.DAY = @d1 AND et.MONTH = @m1 AND et.YEAR = @y1)SELECT 0 as EMP_CODE, '' AS EMP_NAME, 0 AS Row, '0' AS G, '0' AS F, '0' AS S, '0' AS TELSE-- your original query in hereENDAs an aside, I sincerely hope that you are not storing numeric values in varchar fields :-) 这篇关于如果我查询不存在的记录，那么我将不会返回任何内容。我希望在那种情况下返回0。的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！