Export an array containing mysql results to another javascript file-CodePudding

I making use of node.js mysql in my app. I would like to export an array containing results/rows of an SQL select statement to another javascript file and display the values stored in the array.

stats.js

var phonenum='0718900000'
var sql='SELECT name,surname,age from Tbluser WHERE number=?;'
conn.query(sql,[phonenum],function(err,results){
                      if (err){
                        throw err;
                      };
                      /*if (results==0)
                      {
                        let dealersMessage="❌ User not found"
                      }*/
                      
              console.log(results)      
             var datastatagentStore=[];
             results.forEach(item =>{
                 module.exports=datastatagentStore.push({
                        name:item.name,
                        surname:item.surname,
                        age:item.age,
                      })
                    })

app.js

 var{datastatagentStore}=require('../functions/stats.js')

 console.log('User details ' datastatagentStore);

CodePudding user response：

Based on a comment above:

My goal is to execute the query and display the results to the user every time the user selects the 'view my details' button.

Then you don't want to export the results, you want to export the function which performs the query. That function would return [a Promise which resolves to] the results.

If conn.query returns a Promise then it might look something like this:

var getUserDetails = function (phonenum) {
  var sql='SELECT name,surname,age from Tbluser WHERE number=?;'
  return conn.query(sql, [phonenum], function(err, results) {
    if (err) {
      throw err;
    };
    console.log(results)      
    var datastatagentStore = [];
    results.forEach(item => {
      datastatagentStore.push({
        name:item.name,
        surname:item.surname,
        age:item.age,
      })
    });
    return datastatagentStore;
  });
};

module.exports = getUserDetails;

Though I don't know if conn.query does return a Promise. If it doesn't, you can manually create one:

var getUserDetails = function (phonenum) {
  return new Promise(function (resolve, reject) {
    var sql='SELECT name,surname,age from Tbluser WHERE number=?;'
    conn.query(sql, [phonenum], function(err, results) {
      if (err) {
        reject(err);
      };
      console.log(results)      
      var datastatagentStore = [];
      results.forEach(item => {
        datastatagentStore.push({
          name:item.name,
          surname:item.surname,
          age:item.age,
        })
      });
      resolve(datastatagentStore);
    });
  });
};

module.exports = getUserDetails;

Note the use of resolve and reject here to manually complete the Promise. But however you structure it, the overall point is that your module export wouldn't be the results of having executed the query, it would be the function to execute the query. And since executing the query is an asynchronous operation, that function should return a Promise.

Then you can use it like any other asynchronous operation:

var datastatagentStore = require('../functions/stats.js');

datastatagentStore('0718900000').then(function (details) {
  console.log('User details ', details);
});