验证表单内容是否符合数据库字段的规则

var fs = require('fs');
var DBstructure = fs.readFileSync(global.rootPath+"/db.json","utf8");//数据结构文件内容
var schema = function(tablename){
this.columns = JSON.parse(DBstructure)[tablename];
}
exports.schema = schema;
//验证数据合法性
schema.prototype.validparam = function(data){
for(var p in data){
var err = validRouter(p,data[p],this.columns);
if(err) {
return err;
break;
}
}
}
//根据不同数据类型,执行不同的函数
var types = [];
types["int"]=validInt;
types["varchar"]=validLength;
//types["datetime"]=validDate;
//必填项验证
function notEmpty(value){
return value?true:false;
}
//验证整型
function validInt(column,value){
if(isNaN(value)) {
return column.comment+"不是数字";
}
else
return "";
}
//验证长度
function validLength(column,value){
if(value.length>parseInt(column.length))
return column.comment+"内容过长";
else
return "";
}
//分发到不同的验证函数
var validRouter = function(key,value,column){
if(column[key]) {
//字段非空统一验证
if (column[key].isnull == "NO") {
if (!notEmpty(value))
return column[key].comment+"不能为空";
}
if (typeof types[column[key].type] == "function") {
var re = types[column[key].type](column[key], value);
return re;
}
else
return "";
}
else
return "";
}

var schema = require("./schema").schema;
var userSchema = new schema("t_user");
var err = userSchema.validparam(data);
if (err) {
res.write(req.query.jsoncallback + "(" + JSON.stringify(Util.errorMessage(err)) + ")");
res.end();
return;
}