Create Database Tabel Only If Not Exists with JavaScript

gistfile1.txt

// after this function is executed, it will return true/false to callback
// callback should be a function that require a boolean parameter
function isDataExists(callback) {
    getDatabase().transaction(function(trx) {
			worship.createTableIfNotExists(trx, function() {
				var sql = "SELECT * FROM worshipPlaces";
				console.log("Executing "+sql);
				trx.executeSql(sql, null, function(trx, results) {
					console.log("Results: "+results.rows.length);

					if (results.rows.length > 0) {
						callback(true);
					} else {
						callback(false);
					}
				});	
			});
		});
}

// trx is transaction object as parameter from above function
// callback called only when SQL query is succeed
function createTableIfNotExists(trx, callback) {
		var sql = "CREATE TABLE IF NOT EXISTS worshipPlaces (placemark_id unique, religion, name, address, lat, lng)";
		trx.executeSql(sql, null, 
			function(transaction, sqlResultSet) {
				console.log("Table creation success");
				callback();
			},
			function(transaction, error) {
				console.log("Error: "+error.message);
			}
		);
}