js+html5操作sqlite数据库的方法
本文实例讲述了js+html5操作sqlite数据库的方法。分享给大家供大家参考,具体如下:
//copyrightbylanxyoulanxyou[at]gmail.com varlanxDB=function(dbname){ vardb=openDatabase(dbname,'1.0.0','',65536); return{ //返回数据库名 getDBName:function(){ returndbname; }, //初始化数据库,如果需要则创建表 init:function(tableName,colums){ this.switchTable(tableName); colums.length>0?this.createTable(colums):''; returnthis; }, //创建表,colums:[name:字段名,type:字段类型] createTable:function(colums){ varsql="CREATETABLEIFNOTEXISTS"+this._table; vart; if(columsinstanceofArray&&colums.length>0){ t=[]; for(variincolums){ t.push(colums[i].name+''+colums[i].type); } t=t.join(','); }elseif(typeofcolums=="object"){ t+=colums.name+''+colums.type; } sql=sql+"("+t+")"; varthat=this; db.transaction(function(t){ t.executeSql(sql); }) }, //切换表 switchTable:function(tableName){ this._table=tableName; returnthis; }, //插入数据并执行回调函数,支持批量插入 //data为Array类型,每一组值均为Object类型,每一个Obejct的属性应为表的字段名,对应要保存的值 insertData:function(data,callback){ varthat=this; varsql="INSERTINTO"+this._table; if(datainstanceofArray&&data.length>0){ varcols=[],qs=[]; for(variindata[0]){ cols.push(i); qs.push('?'); } sql+="("+cols.join(',')+")Values("+qs.join(',')+")"; }else{ returnfalse; } varp=[], d=data, pLenth=0, r=[]; for(vari=0,dLength=d.length;i<dLength;i++){ vark=[]; for(varjind[i]){ k.push(d[i][j]); } p.push(k); } varqueue=function(b,result){ if(result){ r.push(result.insertId||result.rowsAffected); } if(p.length>0){ db.transaction(function(t){ t.executeSql(sql,p.shift(),queue,that.onfail); }) }else{ if(callback){ callback.call(this,r); } } } queue(); }, _where:'', //where语句,支持自写和以对象属性值对的形式 where:function(where){ if(typeofwhere==='object'){ varj=this.toArray(where); this._where=j.join('and'); }elseif(typeofwhere==='string'){ this._where=where; } returnthis; }, //更新数据,data为属性值对形式 updateData:function(data,callback){ varthat=this; varsql="Update"+this._table; data=this.toArray(data).join(','); sql+="Set"+data+"where"+this._where; this.doQuery(sql,callback); }, //根据条件保存数据,如果存在则更新,不存在则插入数据 saveData:function(data,callback){ varsql="Select*from"+this._table+"where"+this._where; varthat=this; this.doQuery(sql,function(r){ if(r.length>0){ that.updateData(data,callback); }else{ that.insertData([data],callback); } }); }, //获取数据 getData:function(callback){ varthat=this; varsql="Select*from"+that._table; that._where.length>0?sql+="where"+that._where:""; that.doQuery(sql,callback); }, //查询,内部方法 doQuery:function(sql,callback){ varthat=this; vara=[]; varbb=function(b,result){ if(result.rows.length){ for(vari=0;i<result.rows.length;i++){ a.push(result.rows.item(i)); } }else{ a.push(result.rowsAffected); } if(callback){ callback.call(that,a); } } db.transaction(function(t){ t.executeSql(sql,[],bb,that.onfail); }) }, //根据条件删除数据 deleteData:function(callback){ varthat=this; varsql="deletefrom"+that._table; that._where.length>0?sql+="where"+that._where:''; that.doQuery(sql,callback); }, //删除表 dropTable:function(){ varsql="DROPTABLEIFEXISTS"+this._table; this.doQuery(sql); }, _error:'', onfail:function(t,e){ this._error=e.message; console.log('----sqlite:'+e.message); }, toArray:function(obj){ vart=[]; obj=obj||{}; if(obj){ for(variinobj){ t.push(i+"='"+obj[i]+"'"); } } returnt; } } } /* examples: vardb=newlanxDB('testDB'); db.init('channel_list',[{name:'id',type:'integerprimarykeyautoincrement'},{name:'name',type:'text'},{name:'link',type:'text'},{name:'cover',type:'text'},{name:'updatetime',type:'integer'},{name:'orders',type:'integer'}]); db.init('feed_list',[{name:'parentid',type:'integer'},{name:'feed',type:'text'}]); db.switchTable('channel_list').insertData([{name:'aa',link:'ss',updatetime:newDate().getTime()},{name:'bb',link:'kk',updatetime:newDate().getTime()}]); db.where({name:'aa'}).getData(function(result){ console.log(result);//result为Array }); db.where({name:'aa'}).deleteData(function(result){ console.log(result[0]);//删除条数 }); db.where({name:'bb'}).saveData({link:'jj'},function(result){ console.log(result);//影响条数 }) }) */
希望本文所述对大家JavaScript程序设计有所帮助。