node.js-MySQL COUNT 记录数
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/11412599/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
node.js-MySQL COUNT the number of records
提问by Shekhar
I have following code.
我有以下代码。
var mysql = require('mysql');
var connection = mysql.createConnection({
host : 'localhost',
user : 'root',
password : '',
database : 'test'
});
connection.connect();
var userdata = '24';
var sql = 'SELECT COUNT(*) FROM names WHERE age = ?'
connection.query(sql, [userdata], function(err, rows, fields) {
if (err) throw err;
console.log('Query result: ', rows);
});
connection.end();
I want to get the total number of records from table 'names' where 'age' = 24. I receive the following on my node.js command prompt.
我想从表 'names' 中获取记录总数，其中 'age' = 24。我在 node.js 命令提示符下收到以下内容。
Query result: [ { 'COUNT(*)': '14' } ]
My question is how to store this number 14 in a variable for further use.
我的问题是如何将这个数字 14 存储在一个变量中以供进一步使用。
I know I can do this just by changing the 'sql' line to
我知道我可以通过将“sql”行更改为
var sql = 'SELECT * FROM names WHERE age = ?'
and then console line to
然后控制台行到
console.log('Query result: ', rows.length);
But still is there another way?
但是还有别的办法吗？
回答by Nemanja
Rewrite the
重写
var sql = 'SELECT COUNT(*) FROM names WHERE age = ?'
To look like, i.e.:
看起来像，即：
var sql = 'SELECT COUNT(*) AS namesCount FROM names WHERE age = ?'
Then, you will get Query result: [ { 'namesCount': '14' } ].
然后，您将获得查询结果： [ { 'namesCount': '14' } ].
so now you have
所以现在你有
rows[0].namesCount
Good enough?
够好了？
