entityMap|blocks|key|7isgf|text|另一种方式是使用IsNull()函数，例如：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|ampau|import+{+IsNull+}+from+"typeorm";
return+await+getRepository(User).findOne({
++++where:+{+
++++++username:+IsNull()
++++}
});|code-block|syntax|javascript|4k346^0|8|8|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|M|9|@$A|N|B|O|C|D]]|E|@]|F|$]]|$2|G|4|H|6|I|8|P|9|@]|E|@]|F|$J|K]]|$2|L|4|-4|6|7|8|Q|9|@]|E|@]|F|$]]]]

Another way is you can use <code>IsNull()</code> function, for example:

<pre class="lang-js prettyprint-override"><code>import { IsNull } from "typeorm";
return await getRepository(User).findOne({
 where: { 
 username: IsNull()
 }
});
</code></pre>

entityMap|blocks|key|8qkej|text|如果有人在寻找NOT+NULL，它应该是这样的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2r4ru|import+{+IsNull,+Not+}+from+"typeorm";

return+await+getRepository(User).findOne({
++++where:+{+
++++++username:+Not(IsNull())
++++}
});|code-block|syntax|javascript|ffe50^0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|I|9|@]|A|@]|B|$]]|$2|C|4|D|6|E|8|J|9|@]|A|@]|B|$F|G]]|$2|H|4|-4|6|7|8|K|9|@]|A|@]|B|$]]]]

If someone is looking for NOT NULL, it would be like this:
<pre><code>import { IsNull, Not } from &quot;typeorm&quot;;

return await getRepository(User).findOne({
 where: { 
 username: Not(IsNull())
 }
});

</code></pre>

entityMap|0|type|LINK|mutability|MUTABLE|data|url|http://typeorm.io/#/select-query-builder|blocks|key|9cmu9|text|您可以使用QueryBuilder来实现此目的：|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|904mm|const+users+=+await+userRepository.createQueryBuilder("user")
+++++.where("user.name+IS+NULL")
+++++.getMany();|code-block|syntax|javascript|ebmnl^0|5|C|0|0|0^^$0|$1|$2|3|4|5|6|$7|8]]]|9|@$A|B|C|D|2|E|F|Q|G|@]|H|@$I|R|J|S|A|T]]|6|$]]|$A|K|C|L|2|M|F|U|G|@]|H|@]|6|$N|O]]|$A|P|C|-4|2|E|F|V|G|@]|H|@]|6|$]]]]

You can use <a href="http://typeorm.io/#/select-query-builder" rel="noreferrer">QueryBuilder</a> for this purpose:

<pre><code>const users = await userRepository.createQueryBuilder("user")
 .where("user.name IS NULL")
 .getMany();
</code></pre>

entityMap|blocks|key|4uqn3|text|除了hungneox答案之外，你还应该知道你有很多预定义的运算符。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|d1f21|这来自定义它的文件：|bv5sc|export+declare+type+FindOperatorType+=+"not"+%7C+
"lessThan"+%7C+
"lessThanOrEqual"+%7C+
"moreThan"+%7C+
"moreThanOrEqual"+%7C+
"equal"+%7C+
"between"+%7C+
"in"+%7C+
"any"+%7C+
"isNull"+%7C+
"like"+%7C+
"raw";|code-block|syntax|javascript|1s78l|以上每一项都可以在"Operator“部分进行设置：|okh6|{+
++where:+{+
++++propertyToCheck:+<Operator>
++}
}|1pt9n|你只需从@typeorm包中导入并像使用函数一样使用它，例如LessThan()：|4cls2|import+{+Repository,+Between,+IsNull,+LessThan+}+from+'typeorm';

{+
++where:+{+
++++age:+LessThan(50)
++}
}|1u6e5|如果你想掌握typeorm，这是一个非常强大和重要的工具:)祝你好运！|f8nl5^0|0|0|0|0|0|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|U|9|@]|A|@]|B|$]]|$2|C|4|D|6|7|8|V|9|@]|A|@]|B|$]]|$2|E|4|F|6|G|8|W|9|@]|A|@]|B|$H|I]]|$2|J|4|K|6|7|8|X|9|@]|A|@]|B|$]]|$2|L|4|M|6|G|8|Y|9|@]|A|@]|B|$H|I]]|$2|N|4|O|6|7|8|Z|9|@]|A|@]|B|$]]|$2|P|4|Q|6|G|8|10|9|@]|A|@]|B|$H|I]]|$2|R|4|S|6|7|8|11|9|@]|A|@]|B|$]]|$2|T|4|-4|6|7|8|12|9|@]|A|@]|B|$]]]]

In addition to hungneox answer you should know that you have a lot of predefined operators.

This is from the file that defines it:

<pre><code>export declare type FindOperatorType = "not" | 
"lessThan" | 
"lessThanOrEqual" | 
"moreThan" | 
"moreThanOrEqual" | 
"equal" | 
"between" | 
"in" | 
"any" | 
"isNull" | 
"like" | 
"raw";
</code></pre>

Each of the above can be set in the "Operator" part here:

<pre><code>{ 
 where: { 
 propertyToCheck: &lt;Operator&gt;
 }
}
</code></pre>

You just import it from the @typeorm package and use it like a function e.g LessThan():

<pre><code>import { Repository, Between, IsNull, LessThan } from 'typeorm';

{ 
 where: { 
 age: LessThan(50)
 }
}
</code></pre>

This is really strong and important tool to know if you want to master typeorm :)
Good luck!

entityMap|blocks|key|2i2cn|text|我真的不喜欢使用TypeORM中的QueryBuilder来完成这项工作，因为在我看来，在使用FindConditions时，这应该被视为预期的结果。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|bimic|不幸的是，使用类似以下代码的代码：|3pd10|async+articleRequests(
++accepted?:+ArticleRequestAcceptance,
):+Promise<ArticleRequest[]>+{
++const+where:+FindConditions<ArticleRequest>[]+%7C+FindConditions<ArticleRequest>+=+{};

++if+(accepted+!==+undefined)+{
++++switch+(accepted)+{
++++++case+ArticleRequestAcceptance.Accepted:
++++++++where.accepted+=+true;
++++++++break;
++++++case+ArticleRequestAcceptance.Rejected:
++++++++where.accepted+=+false;
++++++++break;
++++++case+ArticleRequestAcceptance.NotReviewedYet:
++++++++where.accepted+=+undefined;
++++++++break;
++++}
++}

++return+await+ArticleRequest.find({+where+}).catch(reason+=>+{
++++throw+reason.message;
++});
}|code-block|syntax|javascript|enqs2|TypeORM将为您提供如下所示的SQL查询：|am73r|SELECT+'...'+WHERE+"ArticleRequest"."accepted"+=+NULL|31c09|因为，从TypeORM日志输出...+WHERE+"ArticleRequest"."accepted"+=+@0+--+PARAMETERS:+[null]中可以看出，在参数数组中，带有SQL值的属性(在本例中为accepted)被转换为null，然后它们被简单地注入到string中。|2ld7d|根据SQL标准，任何与null的比较都会产生null，因此对于SQL中的比较操作符，如=或<>，这应该是没有意义的，但原因是与null进行比较意味着“未知”，所以为什么这样的查询不会返回任何结果。如果你问我，SQL在这里被破坏了。|3depf|所以，正如@hungneox所说，解决方案是使用IsNull()，它为您需要查询的特定列返回一个特殊的FindOperator，作为IS+NULL而不是=+NULL。|6pjrg|如下所示：|20q8i|++if+(accepted+!==+undefined)+{
++++switch+(accepted)+{
++++++case+ArticleRequestAcceptance.Accepted:
++++++++where.accepted+=+true;
++++++++break;
++++++case+ArticleRequestAcceptance.Rejected:
++++++++where.accepted+=+false;
++++++++break;
++++++case+ArticleRequestAcceptance.NotReviewedYet:
++++++++where.accepted+=+IsNull();
++++++++break;
++++}
++}|1fiqk^0|H|C|1B|E|0|0|0|0|0|F|1S|2Z|8|3C|4|0|B|4|M|4|17|1|19|2|0|O|8|1F|C|1U|7|24|6|0|0|0^^$0|$]|1|@$2|3|4|5|6|7|8|12|9|@$A|13|B|14|C|D]|$A|15|B|16|C|D]]|E|@]|F|$]]|$2|G|4|H|6|7|8|17|9|@]|E|@]|F|$]]|$2|I|4|J|6|K|8|18|9|@]|E|@]|F|$L|M]]|$2|N|4|O|6|7|8|19|9|@]|E|@]|F|$]]|$2|P|4|Q|6|K|8|1A|9|@]|E|@]|F|$L|M]]|$2|R|4|S|6|7|8|1B|9|@$A|1C|B|1D|C|D]|$A|1E|B|1F|C|D]|$A|1G|B|1H|C|D]]|E|@]|F|$]]|$2|T|4|U|6|7|8|1I|9|@$A|1J|B|1K|C|D]|$A|1L|B|1M|C|D]|$A|1N|B|1O|C|D]|$A|1P|B|1Q|C|D]]|E|@]|F|$]]|$2|V|4|W|6|7|8|1R|9|@$A|1S|B|1T|C|D]|$A|1U|B|1V|C|D]|$A|1W|B|1X|C|D]|$A|1Y|B|1Z|C|D]]|E|@]|F|$]]|$2|X|4|Y|6|7|8|20|9|@]|E|@]|F|$]]|$2|Z|4|10|6|K|8|21|9|@]|E|@]|F|$L|M]]|$2|11|4|-4|6|7|8|22|9|@]|E|@]|F|$]]]]

I really don't like to have to use the <code>QueryBuilder</code> from TypeORM for this as this should, in my opinion, be treated as expected when using <code>FindConditions</code>.

Unfortunately, with something like the following code:

<pre><code>async articleRequests(
 accepted?: ArticleRequestAcceptance,
): Promise&lt;ArticleRequest[]&gt; {
 const where: FindConditions&lt;ArticleRequest&gt;[] | FindConditions&lt;ArticleRequest&gt; = {};

 if (accepted !== undefined) {
 switch (accepted) {
 case ArticleRequestAcceptance.Accepted:
 where.accepted = true;
 break;
 case ArticleRequestAcceptance.Rejected:
 where.accepted = false;
 break;
 case ArticleRequestAcceptance.NotReviewedYet:
 where.accepted = undefined;
 break;
 }
 }

 return await ArticleRequest.find({ where }).catch(reason =&gt; {
 throw reason.message;
 });
}
</code></pre>

TypeORM gets you a SQL query that looks like this:

<pre class="lang-sql prettyprint-override"><code>SELECT '...' WHERE "ArticleRequest"."accepted" = NULL
</code></pre>

because, as can be seen from TypeORM log output, <code>... WHERE "ArticleRequest"."accepted" = @0 -- PARAMETERS: [null]</code>, properties with <code>undefined</code> values (<code>accepted</code> in this case) get converted to <code>null</code>s inside the parameters array and then they are simply injected into the SQL string.

The SQL standard says that any comparison with <code>null</code> results in <code>null</code> so for comparison operators, like <code>=</code> or <code>&lt;&gt;</code>, in SQL this should make no sense, but the reasoning is that comparing to null means "unknown" so that why such queries don't return any results. If you ask me, SQL is broken here.

So yeah, as @hungneox said, the solution is to use <code>IsNull()</code> which returns a special <code>FindOperator</code> for that specific column you need to be queried as <code>IS NULL</code> and not <code>= NULL</code>.

Like this:

<pre><code> if (accepted !== undefined) {
 switch (accepted) {
 case ArticleRequestAcceptance.Accepted:
 where.accepted = true;
 break;
 case ArticleRequestAcceptance.Rejected:
 where.accepted = false;
 break;
 case ArticleRequestAcceptance.NotReviewedYet:
 where.accepted = IsNull();
 break;
 }
 }
</code></pre>

In my queries I'm using TypeORM <code>find</code> option.
How can I have <code>IS NULL</code> condition in the <code>where</code> clause?

How can I have IS NULL condition in TypeORM find options?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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 在我的查询中，我使用了TypeORM find选项。如何在where子句中包含IS NULL条件？ 

问如何在TypeORM查找选项中具有IS NULL条件？
EN

回答 5

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问如何在TypeORM查找选项中具有IS NULL条件？
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