javascript 如何关闭 node.js 中的数据库连接？
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How to close database connection in node.js?
提问by Vardan
When i am closing database connection in node.jsi am getting this error
当我在node.js 中关闭数据库连接时出现此错误
Cannot enqueue Query after invoking quit.
Cannot enqueue Query after invoking quit.
Here is my code
这是我的代码
socket.on('adminConnect', function (email) {
connection = mysql.createConnection(db_config); // db_config has all details of database
connection.connect(); // no problem in connection
connection.query("SELECT id FROM user WHERE email = '" + email + "' ", function (err, results, fields) {
if (err) throw err;
if (results[0]) {
// Some code
connection.end(); // its giving error "Cannot enqueue Query after invoking quit."
} else {
console.log("no id");
}
});
});
采纳答案by randunel
In general, you reuse connections instead of opening/closing all the time.
通常，您重用连接而不是一直打开/关闭。
To answer your question, this is how:
要回答您的问题，方法如下：
connection.end();
Try putting the line outside the callback, because all the queries must complete before ending a connection, so you're safe like this:
尝试将该行放在回调之外，因为所有查询都必须在结束连接之前完成，因此您可以像这样安全：
connection.query(.......);
connection.end();
Your code would then be:
您的代码将是：
socket.on('adminConnect', function (email) {
connection = mysql.createConnection(db_config); // db_config has all details of database
connection.connect(); // no problem in connection
connection.query("SELECT id FROM user WHERE email = '" + email + "' ", function (err, results, fields) {
if (err) throw err;
if (results[0]) {
// Some code
} else {
console.log("no id");
}
});
connection.end();
});
