add book

Qt6QMLBeginnersCode/13-Storage/5-SQLite/Database.js

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+// Copyright (c) Daniel Gakwaya.
+// SPDX-License-Identifier: MIT
+
+function dbInit(){
+    console.log(" Initializing database...")
+
+    db = LocalStorage.openDatabaseSync("sqlitedemodb", "1.0", "SQLite Demo database", 100000);
+    db.transaction( function(tx) {
+        print('... create table')
+        tx.executeSql('CREATE TABLE IF NOT EXISTS sqlitedemotable(name TEXT, value TEXT)');
+    });
+}
+
+
+function storeData(){
+    console.log(" Storing data...")
+
+    //Check if the database was ever created
+    if (!db){
+        return ;
+    }
+
+    db.transaction(function(tx){
+        //Check if sqlitedemo entry is available in database table
+        var result = tx.executeSql('SELECT * from sqlitedemotable where name = "sqlitedemo"');
+
+        //Prepare json object data from qml code
+        var obj = { x: rootId.x, y: rootId.y,
+            width : rootId.width,height : rootId.height,
+            colorred : rectId.color.r,colorgreen : rectId.color.g ,
+            colorblue : rectId.color.b };
+
+        if ( result.rows.length ===1 ){
+            //Update
+            console.log("Updating database table...")
+            result = tx.executeSql('UPDATE sqlitedemotable set value=? where name="sqlitedemo"',
+                                    [JSON.stringify(obj)])
+        }else{
+            //Create entry
+            console.log("Creating new database table entry")
+            result = tx.executeSql('INSERT INTO sqlitedemotable VALUES (?,?)',
+                                    ['sqlitedemo', JSON.stringify(obj)])
+        }
+
+    });
+
+}
+
+
+function readData(){
+    console.log(" Reading data...")
+
+    if (!db){
+        return ;
+    }
+
+    db.transaction( function(tx) {
+        print('... Reading data from database')
+        var result = tx.executeSql('select * from sqlitedemotable where name="sqlitedemo"');
+
+        if(result.rows.length === 1){
+            //We have data that we can work  with
+
+            // get the value column
+            var value = result.rows[0].value;
+            // convert to JS object
+            var obj = JSON.parse(value)
+
+            // apply to object
+            rootId.x = obj.x;
+            rootId.y = obj.y;
+            rootId.width= obj.width;
+            rootId.height = obj.height
+            rectId.color= Qt.rgba(obj.colorred,obj.colorgreen,obj.colorblue,1)
+        }
+
+    });
+
+}