HTML5 Web 数据库的使用
针对HTML5 Web数据库的封装如下：
备注来自网络：
//自定义的数据库操作类
var Cls_websql = function(db_name,config){
//初始化变量
var cf= config?config:{},
cfg = {
version: cf.version?cf.version:'1.0',desc: cf.desc?cf.desc:'数据库'+db_name,size: cf.size?cf.size:10*1024
},
log= function(msg, cat, src){
if (window['console'] !== undefined && console.log) {
console[cat && console[cat] ? cat : 'log'](msg);
}
},
//还不成熟，sql中不能包含"?",例"select user where title like 'tb?'"
formatSql= function(sql,data){
var count=0;
return sql.replace(/(\?)/g, function(a,b){
return data[count++];
});
},
//初始化数据库
db= function(){
if(window['openDatabase'] !== undefined){
log("数据库连接成功");
return openDatabase(db_name, cfg.version , cfg.desc , cfg.size);
}else{
log("数据库连接失败");
return null;
}
}();
this.db= db;
//执行sql操作
this.execSql= function(sql,data,success,failure){
if(!db){
log("请先初始化数据库和表。");
return;
}
if(!data){
data= [];
}
if (success === undefined){
success = function(tx, results){
log("操作成功:"+formatSql(sql,data));
}
}
var errfun= toString.call(failure) === '[object Function]'?
function(tx, err){
failure.call(this,tx,err,formatSql(sql,data));
} :
function(tx, err){
log("操作失败! msg:"+err.message+" sql:"+formatSql(sql,data));
};
//真正执行sql的地方
db.transaction(function(tx){
try{
tx.executeSql(sql,data,success,errfun)
}catch(e){
log("数据库执行失败:"+e.message);
}
});
};
};
使用如下：
<!DOCTYPE html>
<html>
<head>
<title>测试 WebSQL Database</title>
<meta charset="utf-8" />
</head>
<body onload="init()">
<h1>Web SQL Database</h1>
<div id="info"></div>
<div id="result"></div>
<button onclick="javascript:query();" value="查询"></button>
</body>
<script src="../js/WebSQLDatabase.js"></script>
<script>
function init() {
var websql = new Cls_websql("stationList", {});
websql.execSql('CREATE TABLE IF NOT EXISTS SETS (key unique, value)');
}
function query() {
var websql = new Cls_websql("stationList", {});
websql.execSql("select * from sets ", [], function() {
alert('success');
}, function() {
alert('failure');
})
}
</script>
</html>