blocks|key|139804|text|它可能不是最好的解决方案，但是您可以使用：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|139805|let+backend_mysql_res:+any+=+await+mysql_connection.query(`SELECT+*+FROM+data.table+ORDER+BY+time+DESC+LIMIT+1`);|code-block|syntax|javascript|139806|这样你就可以访问你需要的字段了。使用：|139807|console.log(backend_mysql_res)|139808|看看结果。|139809|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

<p>It could be not the best solution, however you can use:</p>
<pre><code>let backend_mysql_res: any = await mysql_connection.query(`SELECT * FROM data.table ORDER BY time DESC LIMIT 1`);
</code></pre>
<p>That should give you access to the fields you need.
Use:</p>
<pre><code>console.log(backend_mysql_res)
</code></pre>
<p>to see the results.</p>


blocks|key|450410|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|450411|我正在使用自定义函数。不确定这是否是您正在寻找的解决方案，但它确实适用于单个查询。仍在处理多个查询支持。|450412|首先，我为mysql连接查询创建了一个包装器。我们可以在下面的打字稿中找到。现在，可能有一个更好的方法，所以可以建议对此进行编辑。|450413|​|450414|import+{
++createPool
}+from+"mysql2/promise";
var+pool+=+createPool({
++waitForConnections:+true,
++connectionLimit:+10,
++host:+process.env.DBHOST,
++port:+parseInt(process.env.DBPORT),
++user:+process.env.DBUSER,
++password:+process.env.DBPASSWORD,
++database:+process.env.DB_NAME,
++multipleStatements:+true,
++connectTimeout:+30000,
});
export+const+fireQuery+=+async+<
++T+extends+RowDataPacket[][]+%7C+RowDataPacket[]+%7C+OkPacket+%7C+OkPacket[]+%7C+ResultSetHeader+>+(QUERY:+string,+PARAMS:+any[]+=+[]):+Promise+<+T+extends+RowDataPacket[][]+%7C+RowDataPacket[]+%7C+OkPacket+%7C+OkPacket[]+%7C+ResultSetHeader+?+T+:+RowDataPacket[][]+%7C+RowDataPacket[]+%7C+OkPacket+%7C+OkPacket[]+%7C+ResultSetHeader+>+=>+{
++++const+connection+=+await+pool.getConnection();
++++try+{
++++++console.log("starting+transaction...",+QUERY,+PARAMS);
++++++await+connection.beginTransaction();

++++++console.log("running+query...");
++++++let+queryResult+=+await+connection.query+<
++++++++T+extends+%7C
++++++++OkPacket+%7C
++++++++ResultSetHeader+%7C
++++++++RowDataPacket[]+%7C
++++++++RowDataPacket[][]+%7C
++++++++OkPacket[]+?
++++++++T+:+OkPacket+%7C+ResultSetHeader+%7C+RowDataPacket[]+%7C+RowDataPacket[][]+%7C+OkPacket[]+>+(QUERY,+PARAMS);
++++++console.log("committing+transaction...");
++++++await+connection.commit();
++++++console.log("transaction+committed.");
++++++return+queryResult[0];
++++}+catch+(error)+{
++++++Sentry.captureException(error);
++++++connection.rollback();
++++++console.error("an+error+occurred:",+error);
++++++throw+error;
++++}+finally+{
++++++connection.release();
++++}
++};|code-block|syntax|javascript|450415|450416|如下所示。|450417|用于单次查询|450418|450419|export+interface+ISelectQueryInterface+extends+RowDataPacket+{
col1:+string;
col2:+number;
col3:+boolean;
}

const+getUserResult+=+await+fireQuery<UserRDataType[]>("select+col1,+col2,+col3+from+table+where+mobileNo+=+?",+[data.mobileNo])|450420|450421|对于多个查询，这有点麻烦，因为我们首先为任何查询定义数据类型，然后为用例提供模式。|450422|450423|export+interface+ISelectQueryInterface1+extends+RowDataPacket+{
++++col1:+string;
++++col2:+number;
++++col3:+boolean;
}
export+interface+ISelectQueryInterface2+extends+RowDataPacket+{
++++col4:+string;
++++col5:+number;
++++col6:+boolean;
}
export+interface+ISelectQueryInterface3+extends+RowDataPacket+{
++++col7:+string;
++++col8:+number;
}
const+output:+[ISelectQueryInterface1[],+ISelectQueryInterface2[],+ISelectQueryInterface3[]]+=+await+fireQuery<any>("select+col1,+col2,+col3+from+table+where+mobileNo+=+?;select+col4,+col5,+col6+from+table+where+email+=+?;select+col7,+col8+from+table;",+["1234567890",+"abcd@gmail.com"]);|450424|450425|entityMap^0|0|0|0|0|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|-4|4|5|6|12|7|@]|8|@]|9|$]]|$1|A|3|B|4|5|6|13|7|@]|8|@]|9|$]]|$1|C|3|D|4|5|6|14|7|@]|8|@]|9|$]]|$1|E|3|F|4|5|6|15|7|@]|8|@]|9|$]]|$1|G|3|H|4|I|6|16|7|@]|8|@]|9|$J|K]]|$1|L|3|F|4|5|6|17|7|@]|8|@]|9|$]]|$1|M|3|N|4|5|6|18|7|@]|8|@]|9|$]]|$1|O|3|P|4|5|6|19|7|@]|8|@]|9|$]]|$1|Q|3|F|4|5|6|1A|7|@]|8|@]|9|$]]|$1|R|3|S|4|I|6|1B|7|@]|8|@]|9|$J|K]]|$1|T|3|F|4|5|6|1C|7|@]|8|@]|9|$]]|$1|U|3|V|4|5|6|1D|7|@]|8|@]|9|$]]|$1|W|3|F|4|5|6|1E|7|@]|8|@]|9|$]]|$1|X|3|Y|4|I|6|1F|7|@]|8|@]|9|$J|K]]|$1|Z|3|F|4|5|6|1G|7|@]|8|@]|9|$]]|$1|10|3|-4|4|5|6|1H|7|@]|8|@]|9|$]]]|11|$]]

<hr />
<p>I am using a Custom function. Not sure if this is the solution you are looking for or not but it does work for a single query. Still working on multiple query support.</p>
<p>Firstly, i have created a wrapper for the mysql connection query. Which we can find it as below in typescript. Now, there might be a better way so feel free to suggest an edit on this.</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>import {
  createPool
} from "mysql2/promise";
var pool = createPool({
  waitForConnections: true,
  connectionLimit: 10,
  host: process.env.DBHOST,
  port: parseInt(process.env.DBPORT),
  user: process.env.DBUSER,
  password: process.env.DBPASSWORD,
  database: process.env.DB_NAME,
  multipleStatements: true,
  connectTimeout: 30000,
});
export const fireQuery = async &lt;
  T extends RowDataPacket[][] | RowDataPacket[] | OkPacket | OkPacket[] | ResultSetHeader &gt; (QUERY: string, PARAMS: any[] = []): Promise &lt; T extends RowDataPacket[][] | RowDataPacket[] | OkPacket | OkPacket[] | ResultSetHeader ? T : RowDataPacket[][] | RowDataPacket[] | OkPacket | OkPacket[] | ResultSetHeader &gt; =&gt; {
    const connection = await pool.getConnection();
    try {
      console.log("starting transaction...", QUERY, PARAMS);
      await connection.beginTransaction();

      console.log("running query...");
      let queryResult = await connection.query &lt;
        T extends |
        OkPacket |
        ResultSetHeader |
        RowDataPacket[] |
        RowDataPacket[][] |
        OkPacket[] ?
        T : OkPacket | ResultSetHeader | RowDataPacket[] | RowDataPacket[][] | OkPacket[] &gt; (QUERY, PARAMS);
      console.log("committing transaction...");
      await connection.commit();
      console.log("transaction committed.");
      return queryResult[0];
    } catch (error) {
      Sentry.captureException(error);
      connection.rollback();
      console.error("an error occurred:", error);
      throw error;
    } finally {
      connection.release();
    }
  };</code></pre>
</div>
</div>
</p>
<p>Which can be used as below.</p>
<p>For Single query</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>export interface ISelectQueryInterface extends RowDataPacket {
col1: string;
col2: number;
col3: boolean;
}

const getUserResult = await fireQuery&lt;UserRDataType[]&gt;("select col1, col2, col3 from table where mobileNo = ?", [data.mobileNo])</code></pre>
</div>
</div>
</p>
<p>for multiple queries, it's a bit hacky as we are first defining data type to any and then providing schema for it for our use case.</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>export interface ISelectQueryInterface1 extends RowDataPacket {
    col1: string;
    col2: number;
    col3: boolean;
}
export interface ISelectQueryInterface2 extends RowDataPacket {
    col4: string;
    col5: number;
    col6: boolean;
}
export interface ISelectQueryInterface3 extends RowDataPacket {
    col7: string;
    col8: number;
}
const output: [ISelectQueryInterface1[], ISelectQueryInterface2[], ISelectQueryInterface3[]] = await fireQuery&lt;any&gt;("select col1, col2, col3 from table where mobileNo = ?;select col4, col5, col6 from table where email = ?;select col7, col8 from table;", ["1234567890", "abcd@gmail.com"]);</code></pre>
</div>
</div>
</p>


<p>I'm using the mysql2/promise library in typescript, however, I can't understand the type of the return of the query method, and I can't solve an error.<br>
My code is below.<br></p>
<pre><code>import * as mysql from &quot;mysql2/promise&quot;;

let mysql_connection: mysql.Connection = await mysql.createConnection({
   //Some options here.
});

let backend_mysql_res: [(mysql.RowDataPacket[][] | mysql.RowDataPacket[] | mysql.OkPacket | mysql.OkPacket[] | mysql.ResultSetHeader), mysql.FieldPacket[]] = await mysql_connection.query(`SELECT * FROM data.table ORDER BY time DESC LIMIT 1`);

//The error occurred this line. 
console.log(backend_mysql_res[0][0]);
</code></pre>
<p>And the error message about the <code>backend_mysql_res[0][0]</code> in the last line of the above code is below.<br></p>
<pre><code>TS7053: Element implicitly has an 'any' type because expression of type '0' can't be used to index type 'RowDataPacket[] | RowDataPacket[][] | OkPacket | OkPacket[] | ResultSetHeader'.   Property '0' does not exist on type 'RowDataPacket[] | RowDataPacket[][] | OkPacket | OkPacket[] | ResultSetHeader'.
</code></pre>
<p>The error message above describes <code>type '0'</code>, however, what is the <code>type '0'</code>? Isn't this type number?<br>
So, I can't find the solution to the problem.<br></p>
<p>What are the proper types of the response of the query method of mysql2/promise?
Furthermore, the above type specification of <code>let backend_mysql_res ...</code> is what I wrote according to the suggestion from the IDE. But I think this is a little too long. So is there a way to sophisticate code?<br></p>
<p>I just began to learn the typescript these days.<br>
Anyone who can help me.<br></p>


The type error about the return of mysql2/promise query

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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我在类型记录中使用mysql2 2/答应库，但是，我无法理解查询方法返回的类型，也无法解决错误。我的密码在下面。import * as mysql from "mysql2/promise";let mysql_connection: mysql.Connection = await mysql.createConne...

问mysql2 2/答应查询返回的类型错误
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问mysql2 2/答应查询返回的类型错误EN