CODEWITHSUNDEEP
angularjssqlitecordovaionic-framework
MagicDragon
MagicDragon

Reputation: 199

Cordova SQLite wait until insert finishes

I have multiple INSERTs I'd like to be done before starting SELECT requests. My problem is that the INSERT is not yet finished when the SELECT fires.

Made a factory for the database handling:
databaseFactory.js

factory.insertIntoTable= function (database, data) {
  var sqlCommand = 'INSERT INTO blablabla';

  database.transaction(function(tx) {
    database.executeSql(sqlCommand, [data.thingsToInsert], function (resultSet) {
      console.log('success: insertIntoTable');
    }, function (error) {
      console.log('SELECT error: ' + error.message);
    });
  }, function(error) {
    console.log('transaction error: ' + error.message);
    database.close();
  }, function() {
    console.log('transaction ok: insertIntoTable');
  });
};

app.js 

ionic.Platform.ready(function () {
  if (window.cordova && window.cordova.plugins.Keyboard) {
    cordova.plugins.Keyboard.hideKeyboardAccessoryBar(true);
    cordova.plugins.Keyboard.disableScroll(true);
  };

  if(window.StatusBar) {
    StatusBar.styleDefault();
  }

  db = window.sqlitePlugin.openDatabase({name: 'myDbName.db', location: 'default'});

  if (window.Connection) {
    if (navigator.connection.type !== Connection.NONE) {
      databaseFactory.createTables(db);

      MyService.getStuffFromAPI().then(function(result) {
        for (var index = 0; index < result[0].campaigns.length; index++) {
          databaseFactory.insertIntoTable(db, result[0].campaigns[index]);
        }

        var selectResult = databaseFactory.selectFromCampaigns();

        console.log(selectResult); //This log comes earlier than the above inserts could finish.

      }, function(result) {
        console.log(result);
      });
    }
  }
});

The INSERT is working fine anyways, I did check it.

I know that the datebase.transaction is asynchronous so also tried it with single db.executeSQL command but had the same problem even with adding $q resolve, reject to the factory. I really could use some help, thanks!

Upvotes: 1

Views: 3306

Answers (2)

MagicDragon
MagicDragon

Reputation: 199

The problem was the way I used the database.transaction(function (tx){}) since it's itself an asynchronous function and inside the function body I can make the synchronous CRUD operations and they will happen in order.
app.js (fixed) 

ionic.Platform.ready(function () {
  if (window.cordova && window.cordova.plugins.Keyboard) {
    cordova.plugins.Keyboard.hideKeyboardAccessoryBar(true);
    cordova.plugins.Keyboard.disableScroll(true);
  };

  if(window.StatusBar) {
    StatusBar.styleDefault();
  }

  db = window.sqlitePlugin.openDatabase({name: 'MagicalWonder.db', location: 'default'});

  if (window.Connection) {
    if (navigator.connection.type !== Connection.NONE) {
      MyService.getMyPreciousData().then(function(result) {

        db.transaction(function(tx) {
          databaseFactory.createTable(tx);              

          for (var index = 0; index < result[0].campaigns.length; index++) {
            databaseFactory.insertIntoTable(tx, result[0].myPreciousData[index]);
          }
          // HERE I CAN MAKE THE SELECT REQUESTS
        }, function(error) {
          console.log('transaction error: ' + error.message);
          database.close();
        }, function() {
          console.log('transactions successfully done.');
        });
      }, function(result) {
        console.log(result);
      });
    }
  }
});

factory method (fixed)

factory.insertIntoTable = function (tx, data) {
  var sqlCommand = 'INSERT INTO wanders (' +
                   'id, ' +
                   'magic_spell) values (?,?)';

  tx.executeSql(sqlCommand, [data.id, data.magic_spell], function (tx, resultSet) {
      console.log('Success: insertIntoBookOfWonder');
  }, function (tx, error) {
    console.log('SELECT error: ' + error.message);
  });
};

Upvotes: 1

Roger Garcia
Roger Garcia

Reputation: 357

Every Insert returns a promise. Keep those promises in an array of promises and use $q.all to wait for all of them to complete.

Example: Factory method used to insert an object

function insert(object){

    var deferred = $q.defer(); //IMPORTANT

    var query = "INSERT INTO objectTable (attr1, attr2) VALUES (?,?)";
    $cordovaSQLite.execute(db, query, [object.attr1, object.attr2]).then(function(res) { //db object is the result of the openDB method
        console.log("INSERT ID -> " + res.insertId);
        deferred.resolve(res); //"return" res in the success method
    }, function (err) {
        console.error(JSON.stringify(err));
        deferred.reject(err); //"return" the error in the error method
    });

    return deferred.promise; //the function returns the promise to wait for
}

And then, in every insert:

promises.push(yourService.insert(obj).then(function(result){ //"result" --> deferred.resolve(res);
    //success code 
}, function(error){ //"error" --> deferred.reject(err);
    //error code
}));

And finally:

$q.all(promises).then(function(){//do your selects}, function(err){//error!});

Hope it helps.

More info about $q and $q.all: https://docs.angularjs.org/api/ng/service/$q#all

And another example: https://www.jonathanfielding.com/combining-promises-angular/

Upvotes: 1

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