如何将NodeJS变量输入到SQL查询中

Question

我想编写一个包含NodeJS变量的SQL查询.当我这样做时,它给我一个'undefined'的错误.

我希望下面的SQL查询识别flightNo变量.如何将NodeJS变量输入到SQL查询中？它周围是否需要特殊字符$或者?.

app.get("/arrivals/:flightNo?", cors(), function(req,res){
var flightNo = req.params.flightNo;

connection.query("SELECT * FROM arrivals WHERE flight = 'flightNo'", function(err, rows, fields) {

Answer 1

您需要将变量的值放入SQL语句中.

这不好:

"SELECT * FROM arrivals WHERE flight = 'flightNo'"

这样可行,但SQL注入攻击不安全:

"SELECT * FROM arrivals WHERE flight = '" + flightNo + "'"

为了安全地从SQL注入,你可以像这样逃避你的价值:

"SELECT * FROM arrivals WHERE flight = '" + connection.escape(flightNo) + "'"

但最好的方法是使用参数替换:

app.get("/arrivals/:flightNo", cors(), function(req, res) {
  var flightNo = req.params.flightNo;

  var sql = "SELECT * FROM arrivals WHERE flight = ?";
  connection.query(sql, flightNo, function(err, rows, fields) {
  });
});

如果要进行多次替换,请使用数组:

app.get("/arrivals/:flightNo", cors(), function(req, res) {
  var flightNo = req.params.flightNo;
  var minSize = req.query.minSize;

  var sql = "SELECT * FROM arrivals WHERE flight = ? AND size >= ?";
  connection.query(sql, [ flightNo, minSize ], function(err, rows, fields) {
  });
});