QT本地存储演示

import QtQml 2.12
import QtQuick 2.12
import QtQuick.LocalStorage 2.12
Item{
    id:idLocalStorageObject
    property var db : null;
    Component.onCompleted: {
        initDB();
    }

    function initDB(){
        db = LocalStorage.openDatabaseSync("AyjGlobalDB","1.0","Ayj UI Global Database",100000);//打开数据库
        db.transaction(function(tx){
            tx.executeSql('CREATE TABLE IF NOT EXISTS GlobalData (key TEXT,value TEXT)');//创建表
        });
    }

    //根据Key查找缓存对象
    function getItem(_key){
        if(!db){return;}
        db.transaction(function(tx){
             let result = tx.executeSql('SELECT * FROM GlobalData WHERE key=?',_key);
             if(result.rows.length===1){
                 let tmpValue = result.rows[0].value;
                 return JSON.parse(tmpValue);
             }
        });

    }

    //根据Key缓存对象
    function setItem(_key,_value){
        if(!db){return;}
        db.transaction(function(tx){
            let result = tx.executeSql('SELECT * FROM GlobalData WHERE key=""');
            if(result.rows.length===1){//update
                result = tx.executeSql('UPDATE GlobalData SET value=? WHERE key=?',JSON.stringify(_value),_key);
            }else{//insert
                result = tx.executeSql('INSERT INTO GlobalData VALUES(?,?,)',_key,JSON.stringify(_value));
            }
        });
    }
}