Web SQL数据库
1、数据库的大小的限制以浏览器而定，一般大小不要超过5MB，如果超过限制，应用程序会提示终端用户是否允许数据限额增长，如果允许，数据库大小限制会提升到10MB，如果拒绝的话，将会提示QUOTA_ERR数据库错误码
2、WebSQL为客户端关系型数据库，但浏览器支持不是很好，目前chrome支持的最好，其他浏览器部分版本支持。
websql.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">
<title></title>
<script type="text/javascript" src="../../js/websql.js" ></script>
</head>
<script>
function creatTable() {
console.log("新建数据库");
websqlOpenDB();
websqlCreatTable(websqlTable);
}
function insterData() {
console.log("插入数据");
websqlInsterDataToTable(websqlTable,"小明","18","175cm","60kg");
websqlInsterDataToTable(websqlTable,"小红","17","160cm","45kg");
websqlInsterDataToTable(websqlTable,"小强","19","185cm","70kg");
}
function updateData() {
console.log("修改数据");
websqlUpdateAData(websqlTable,"小明","1000")
}
function deleteAData() {
console.log("删除一条数据");
websqlDeleteADataFromTable(websqlTable,"小明");
}
function deleteAllData() {
console.log("删除全部数据");
websqlDeleteAllDataFromTable(websqlTable);
}
function selectAData() {
console.log("查找一条数据");
websqlGetAData(websqlTable,"小明");
}
function selectALlData() {
console.log("查找全部数据");
websqlGetAllData(websqlTable);
}
</script>
<style>
.content {
padding-top: 50px;
}
.websql {
margin-top: 10px;
}
/*设置按钮样式*/
.websql button{
height: 44px;
width: 120px;
}
</style>
<body>
<div class="content">
<div class="websql">
<button type="button" onclick="creatTable()">新建数据库</button>
</div>
<div class="websql">
<!--增-->
<button type="button" onclick="insterData()">插入数据</button>
</div>
<div class="websql">
<!--删-->
<button type="button" onclick="deleteAData()">删除一条数据</button>
<button type="button" onclick="deleteAllData()">删除全部数据</button>
</div>
<div class="websql">
<!--改-->
<button type="button" onclick="updateData()">修改数据</button>
</div>
<div class="websql">
<!--查-->
<button type="button" onclick="selectAData()">查找一条数据</button>
<button type="button" onclick="selectALlData()">查找全部数据</button>
</div>
</div>
</body>
</html>
websql.js
/** *数据库操作辅助类,定义对象、数据操作方法都在这里定义 */ var dbname='websql';/*数据库名*/ var version = '1.0'; /*数据库版本*/ var dbdesc = 'websql练习'; /*数据库描述*/ var dbsize = 2*1024*1024; /*数据库大小*/ var dataBase = null; /*暂存数据库对象*/ /*数据库中的表单名*/ var websqlTable = "websqlTable"; /** * 打开数据库 * @returns dataBase:打开成功 null:打开失败 */ function websqlOpenDB(){ /*数据库有就打开 没有就创建*/ dataBase = window.openDatabase(dbname, version, dbdesc, dbsize,function() {}); if (dataBase) { alert("数据库创建/打开成功!"); } else{ alert("数据库创建/打开失败！"); } return dataBase; } /** * 新建数据库里面的表单 * @param tableName:表单名 */ function websqlCreatTable(tableName){ // chinaAreaOpenDB(); var creatTableSQL = 'CREATE TABLE IF NOT EXISTS '+ tableName + ' (rowid INTEGER PRIMARY KEY AUTOINCREMENT, NAME text,AGE text,HEIGHT text,WEIGTH text)'; dataBase.transaction(function (ctx,result) { ctx.executeSql(creatTableSQL,[],function(ctx,result){ alert("表创建成功 " + tableName); },function(tx, error){ alert('创建表失败:' + tableName + error.message); }); }); } /** * 往表单里面插入数据 * @param tableName:表单名 * @param NAME:姓名 * @param AGE:年龄 * @param HEIGHT:身高 * @param WEIGTH:体重 */ function websqlInsterDataToTable(tableName,NAME,AGE,HEIGHT,WEIGTH){ var insterTableSQL = 'INSERT INTO ' + tableName + ' (NAME,AGE,HEIGHT,WEIGTH) VALUES (?,?,?,?)'; dataBase.transaction(function (ctx) { ctx.executeSql(insterTableSQL,[NAME,AGE,HEIGHT,WEIGTH],function (ctx,result){ console.log("插入" + tableName + NAME + "成功"); }, function (tx, error) { alert('插入失败: ' + error.message); }); }); } /** * 获取数据库一个表单里面的所有数据 * @param tableName:表单名 * 返回数据集合 */ function websqlGetAllData(tableName){ var selectALLSQL = 'SELECT * FROM ' + tableName; dataBase.transaction(function (ctx) { ctx.executeSql(selectALLSQL,[],function (ctx,result){ alert('查询成功: ' + tableName + result.rows.length); var len = result.rows.length; for(var i = 0;i < len;i++) { console.log("NAME = " + result.rows.item(i).NAME); console.log("AGE = " + result.rows.item(i).AGE); console.log("HEIGHT = " + result.rows.item(i).HEIGHT); console.log("WEIGTH = " + result.rows.item(i).WEIGTH); console.log("-------- 我是分割线 -------"); } }, function (tx, error) { alert('查询失败: ' + error.message); }); }); } /** * 获取数据库一个表单里面的部分数据 * @param tableName:表单名 * @param name:姓名 */ function websqlGetAData(tableName,name){ var selectSQL = 'SELECT * FROM ' + tableName + ' WHERE NAME = ?' dataBase.transaction(function (ctx) { ctx.executeSql(selectSQL,[name],function (ctx,result){ alert('查询成功: ' + tableName + result.rows.length); var len = result.rows.length; for(var i = 0;i < len;i++) { console.log("NAME = " + result.rows.item(i).NAME); console.log("AGE = " + result.rows.item(i).AGE); console.log("HEIGHT = " + result.rows.item(i).HEIGHT); console.log("WEIGTH = " + result.rows.item(i).WEIGTH); } }, function (tx, error) { alert('查询失败: ' + error.message); }); }); } /** * 删除表单里的全部数据 * @param tableName:表单名 */ function websqlDeleteAllDataFromTable(tableName){ var deleteTableSQL = 'DELETE FROM ' + tableName; localStorage.removeItem(tableName); dataBase.transaction(function (ctx,result) { ctx.executeSql(deleteTableSQL,[],function(ctx,result){ alert("删除表成功 " + tableName); },function(tx, error){ alert('删除表失败:' + tableName + error.message); }); }); } /** * 根据name删除数据 * @param tableName:表单名 * @param name:数据的姓名 */ function websqlDeleteADataFromTable(tableName,name){ var deleteDataSQL = 'DELETE FROM ' + tableName + ' WHERE NAME = ?'; localStorage.removeItem(tableName); dataBase.transaction(function (ctx,result) { ctx.executeSql(deleteDataSQL,[name],function(ctx,result){ alert("删除成功 " + tableName + name); },function(tx, error){ alert('删除失败:' + tableName + name + error.message); }); }); } /** * 根据name修改数据 * @param tableName:表单名 * @param name:姓名 * @param age:年龄 */ function websqlUpdateAData(tableName,name,age){ var updateDataSQL = 'UPDATE ' + tableName + ' SET AGE = ? WHERE NAME = ?'; dataBase.transaction(function (ctx,result) { ctx.executeSql(updateDataSQL,[age,name],function(ctx,result){ alert("更新成功 " + tableName + name); },function(tx, error){ alert('更新失败:' + tableName + name + error.message); }); }); }
