Question

您好我想通过连接3列值更新表列，但问题是如果3列中的任何一列具有空值，我该如何停止更新。

我的查询在下面给出了我想要更新ind_ref 123的记录但是如果我连接的3列的任何值为null，则它不应该更新display_name列。我怎样才能实现它？

update individual_loc
Set individual_loc.display_name=individual_loc.address1+','+INDIVIDUAL_LOCATION.TOWN+','+INDIVIDUAL_LOCATION.COUNTY
where individual_loc.ind_ref=123

Answer 1

只需在NULL子句中添加WHERE支票即可。

UPDATE individual_loc
SET display_name = address1 + ',' + TOWN + ',' + COUNTY
WHERE ind_ref = 123 AND address1 IS NOT NULL AND TOWN IS NOT NULL AND COUNTY IS NOT NULL

Answer 2

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                                        option(next.name()).withValue(String.valueOf(next.ordinal()))
                                )
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            );
}

Answer 3

试试这个

update individual_loc
Set individual_loc.display_name=individual_loc.address1+','+
    individual_loc.TOWN+','+individual_loc.COUNTY
where individual_loc.ind_ref=123 
AND address1 is not null
AND town is not null
AND county is not null

基本上，只有在字段不为空时才执行更新

Answer 4

一种方法是使用COALESCE：

UPDATE individual_loc
SET individual_loc.display_name=COALESCE(individual_loc.address1+','+INDIVIDUAL_LOCATION.TOWN+','+INDIVIDUAL_LOCATION.COUNTY, individual_loc.display_name)
where individual_loc.ind_ref=123;

Answer 5

您还可以使用coalesce()函数

检查空值

update individual_loc
Set individual_loc.display_name=individual_loc.address1+','+INDIVIDUAL_LOCATION.TOWN+','+INDIVIDUAL_LOCATION.COUNTY
where individual_loc.ind_ref=123 
and coalesce(individual_loc.address1+','+INDIVIDUAL_LOCATION.TOWN+','+INDIVIDUAL_LOCATION.COUNTY, 0) <> 0

Answer 6

如果你想避免空问题，只需检查isnull（individual_loc.address1，''）

如果还有别的尝试： IIF（（isnull（address1，''）=''OR isnull（TOWN，''）=''或isnull（COUNTY，''）=''），UPDATE STATEMENT，PRINT'False'）

我想更新表但在更新之前它应该检查空值

6 个答案: