Nsryjdtyk

I have written some code to call a procedure,it's OUT parameter type is cursor(ResultSet),so i have to fetch data from ResultSet,for that i've written one function(fetchRowsFromRS()) which extract data from ResultSet.

1. I've used return statement in fetchRowsFromRS(),but not returning
   anything, getting undefined.


2. When i called fetchRowsFromRS(),control is not pausing execution
   of next lines of code(i'have used Async/await) this is required because i want use extracted data in next lines.

What is the mistake in my code?

db.js

    connection.execute(plsql,bindvars,options,async function (err, result) {

          if (err) {

            console.log(err);

            console.error(err.message);

            doRelease(connection);

            return;

          }



      if(result.outBinds.OUT_STATUS=='SUCCESS'){



        if(result.outBinds.OUT_MENU_NAME.metaData.length=0){



        loginRes.getUserLoginServiceRes.Header.Status=aes.encryption('Failure');



        loginRes.getUserLoginServiceRes.Header.Status_Desc=aes.encryption('No record found in database');

       }else{



   loginRes.getUserLoginServiceRes.Header.Status=aes.encryption('Success');



   loginRes.getUserLoginServiceRes.Header.Status_Desc=aes.encryption('User 

       logged in successfully');

       var numRows=20;

       //calling function to fetch data from ResultSet

       var rsData=await fetchRowsFromRS(connection,result.outBinds.OUT_MENU_NAME,numRows)

    console.log('----------'+rsData);//giving undefined



    //here i want to use ResultSet Data



        }

      }

  })

function to extract data from ResultSet(not returning anything)

function fetchRowsFromRS(connection, resultSet, numRows) {

     resultSet.getRows(numRows,function (err, rows) {

          if (err) {

            console.error(err);

            doClose(connection, resultSet);   // always close the ResultSet

          } else if (rows.length > 0) {

          console.log("fetchRowsFromRS(): Got " + rows.length + " rows");

          console.log(rows); //getting data here





          if (rows.length === numRows)      // might be more rows

            fetchRowsFromRS(connection, resultSet, numRows);

          else

            doClose(connection, resultSet); // always close the ResultSet





        } else { // no rows

          doClose(connection, resultSet);   // always close the ResultSet

        }

        return rows;

      });

  }

fetchRowsFromRS is not returning anything. You don't seem to be using async/await correctly. resultSet.getRows uses a callback. Change it to return a Promise or wrap it in a Promise and return that from fetchRowsFromRS. Then you'll be able to await it.

function fetchRowsFromRS(connection, resultSet, numRows) {

  return resultSet

    .getRows(numRows)

    .then(function(rows) {

      if (rows.length > 0) {

        console.log('fetchRowsFromRS(): Got ' + rows.length + ' rows')

        console.log(rows) //getting data here

        if (rows.length === numRows)

          // might be more rows

          fetchRowsFromRS(connection, resultSet, numRows)

        else doClose(connection, resultSet) // always close the ResultSet

      } else {

        // no rows

        doClose(connection, resultSet) // always close the ResultSet

      }

      return rows

    })

    .catch(function(err) {

      if (err) {

        console.error(err)

        doClose(connection, resultSet) // always close the ResultSet

      }

    })

}

The above will work if, resultSet.getRows(numRows) returns a promise instead of accepting a callback or there is some alternate for resultSet.getRows(numRows) which return a promise.

await fetchRowsFromRS(connection, resultSet, numRows)

will work only if fetchRowsFromRS(connection, resultSet, numRows) returns a promise, which in turn requires everything defines inside the function to return a promise.

OR

Use new Promise

function fetchRowsFromRS(connection, resultSet, numRows) {

  return new Promise(function(resolve, reject) {

    resultSet.getRows(numRows, function(err, rows) {

      if (err) {

        console.error(err)

        doClose(connection, resultSet) // always close the ResultSet

        reject(err)

      } else if (rows.length > 0) {

        console.log('fetchRowsFromRS(): Got ' + rows.length + ' rows')

        console.log(rows) //getting data here



        if (rows.length === numRows)

          // might be more rows

          fetchRowsFromRS(connection, resultSet, numRows)

        else doClose(connection, resultSet) // always close the ResultSet

      } else {

        // no rows

        doClose(connection, resultSet) // always close the ResultSet

      }

      resolve(rows)

    })

  })

}