Node.js将SQL查询结果写入CSV

Question

我目前正在尝试使用Node.js库查询数据库繁琐，然后使用库＆＃34; cdv-write-stream＆＃34;将结果写入CSV文件。我能够成功查询数据库，获取结果并将其写入CSV文件 - 但是，脚本一直在运行以访问该文件。我是node.js的新手，我不确定我做错了什么。

相关守则：

var Connection = require('tedious').Connection;
var csvWriter = require('csv-write-stream');
var sql = require('./sql')
var moment = require('moment');
var writer = csvWriter();
const fs = require('fs');

var headers = [];
var resultRow = [];
var now = moment().format("MM-DD-YYYY");
var config = {
    userName: '**',  
    password: '***',  
    server: '***',  
    options: { encrypt: false, database: 'CordaCustom' }
};
var connection = new Connection(config);
connection.on('connect', function (err) {
    // If no error, then good to proceed.  
    executeStatement();
});

var Request = require('tedious').Request;
var TYPES = require('tedious').TYPES;

function executeStatement() {
    request = new Request(sql['sql'], function (err) {
        if (err) {
            console.log(err);
        }
    });
    var result = "";
    //Write headers to an array.
    request.on('columnMetadata', function (columns){
        columns.forEach(function (column) {
            headers.push(column.colName);
        });
    });
    //Write headers to CSV file
    var writer = csvWriter({ headers: headers });
    writer.pipe(fs.createWriteStream( 'TL_Statistics' + now + '.csv'));
    request.on('row', function (columns) {
        columns.forEach(function (column) {
            if (column.value === null) {
                resultRow.push(' ')
            } else {
                resultRow.push(column.value)
            }
        });
        writer.write(resultRow)
        resultRow = [];
        result = "";
    });

    request.on('done', function (rowCount, more) {
        console.log(rowCount + ' rows returned');

    });
    connection.execSql(request);

}

writer.on('end', function () {
    connection.close();
});
writer.end();