I am using mssql with node.js to connect to an sql server db. I am trying to reduce code by wrapping the connection code in a function with one query parameter. When I call the function from with in a router.get function, it returns undefined.

Any help would be much appreciated.

function sqlCall(query) {
  var connection = new sql.Connection(config, function(err) {
    if (err) {
      console.log("error1");
      return;
    }

    var request = new sql.Request(connection); // or: var request = connection.request();
    request.query(query, function(err, recordset) {
      if (err) {
        console.log("error2");
        return;
      }

      return (recordset);
    });
  });
}

I am using mssql with node.js to connect to an sql server db. I am trying to reduce code by wrapping the connection code in a function with one query parameter. When I call the function from with in a router.get function, it returns undefined.

Any help would be much appreciated.

function sqlCall(query) {
  var connection = new sql.Connection(config, function(err) {
    if (err) {
      console.log("error1");
      return;
    }

    var request = new sql.Request(connection); // or: var request = connection.request();
    request.query(query, function(err, recordset) {
      if (err) {
        console.log("error2");
        return;
      }

      return (recordset);
    });
  });
}

router code

router.get('/', function(req, res) {

  var queryString = "select * from .....";

  res.json(sqlCall(queryString));

  //sqlCall(queryString)

});

• javascript
• node.js
• callback
• node-mssql

Share Improve this question Follow edited Jan 20, 2015 at 10:13 Himmet Avsar 1,5311616 silver badges2323 bronze badges asked Jan 20, 2015 at 9:39 user1781272user1781272 95222 gold badges1414 silver badges2525 bronze badges

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 6

You are trying to treat the sqlCall as a synchronous function with a return value, while the request.query function on the opposite is an asynchronous function, expecting a callback.

Since Node.js uses non blocking IO and callback structures for flow control, using an asynchronous structure based around callbacks is the way to go. In your case this could look like this:

router.get('/', function(req, res) {


  var queryString = "selec * from .....";
  sqlCall(queryString, function(err, data) {
     if (typeof err !== "undefined" && err !== null) {
       res.status(500).send({
         error: err
       });
       return;
     }

     res.json(data);
  });
});

with your other ponent looking like this:

function sqlCall(query, cb) {
  var connection = new sql.Connection(config, function(err) {
    if (typeof err !== "undefined" && err !== null) {
      cb( err );
      return
    }

    var request = new sql.Request(connection); // or: var request = connection.request();
    request.query(query, function(err, recordset) {
      cb( err, recordset );
    });

  });

}