json 데이터 형식 을 기반 으로 한 간단 한 데이터베이스 - jsonDB

/**
 +-----------------------------------------
 * jsonDB 	  json           
 +-----------------------------------------
 * @description		 json    ，  ，     
 * @author	  (web   )	[email protected]
 * @date 2014 6 28 
 * @version	0.1
 * @blog http://blog.csdn.net/thinkercode/
 +-----------------------------------------
 *   ：
 * jsonDB js     ，   json         
 *      json      。jsonDB      HTML5
 *            ，    sql json     
 *    ，          where    ，    ，
 * limit              。  jsonDB   
 *       /     / ，       json   
 *     ，           sql  ，  jsonDB 
 *             ，   jsonDB     sql 
 *       。
 +-----------------------------------------
 *        ：
 * 1.          
 * 2.               
 * 3.         ，          
 * 4.update、delete     order by  ，  limit      
 * 5.  where       ()  where  
 * 6.                
 * 7.           
 * 8.       
 +-----------------------------------------
 * jsonDB   ：
 * jsonDB            ，        
 * jsonDB                      
 *            jsonDB       ，      
 *                  ，               
 *           ，          jsonDB，
 *                
 +-----------------------------------------
 */
(function(window,undefined){
	_jsonDB = window.jsonDB,
	_history = null,
	DBCore = {},
	Database = {},
	DBExpand = {};


	/**
	 * [jsonDB      ，             ]
	 * @param  mixed data 	  
	 * @param  string dbName	     
	 * @return jsonDB
	 */
	var jsonDB = function(data,dbName){

		//          
		if(data){
			dbName = dbName || 'json_db';
			eval('Database.'+ dbName +'= data');
		}

		return jsonDB.fn.init();
	}

	jsonDB.fn = jsonDB.prototype = {
		//     
		init : function (alias){
			if(alias){
				_history = window[alias];
				window[alias] = jsonDB();
			}
			return this;
		},

		query : function(sql){
			var type = sql.match(/^(\w+)/);
			switch(type[0]){
				case 'select' :
				case 'delete' : 
				case 'update' :
					return eval('DBCore.fn.'+ type[0] +'(sql+" ")');
				break;
				default :
					return false;
				break;
			}
		},

		insert : function(data,dbName){
			if(data){
				dbName = dbName || 'json_db';
				eval('Database.'+ dbName +'.push(data)');
			}
			return this;
		},

		findAll : function(dbName){
			if(dbName){
				return eval('Database.'+ dbName);
			}
			return Database;
		}
	};

	/**
	 * [DBExpand          ]
	 */
	DBExpand = DBExpand.prototype = {
		sqlParam : {
			fields : '*',
			table : 'json_db',
			where : null,
			order : null,
			limit : null,
		},

		add : function(data){
			return this.insert(data,this.sqlParam.table);
		},

		select : function(){
			var sql = 'select '+this.sqlParam.fields+' from '+this.sqlParam.table;
			if(this.sqlParam.where){
				sql += ' where '+this.sqlParam.where;
			}
			if(this.sqlParam.order){
				sql += ' order by '+this.sqlParam.order;
			}
			if(this.sqlParam.limit){
				sql += ' limit '+this.sqlParam.limit;
			}

			this.clear();
			return this.query(sql);
		},

		update : function(data){
			if(data.length<1){
				return false;
			}

			var sql = 'update '+this.sqlParam.table+' set '+data;
			if(this.sqlParam.where){
				sql += ' where '+this.sqlParam.where;
			}
			if(this.sqlParam.limit){
				sql += ' limit '+this.sqlParam.limit;
			}
			this.clear();
			return this.query(sql);
		},

		delete : function(){
			if(this.sqlParam.where.length<1){
				return false;
			}

			var sql = 'delete from '+this.sqlParam.table;
			if(this.sqlParam.where){
				sql += ' where '+this.sqlParam.where;
			}
			if(this.sqlParam.limit){
				sql += ' limit '+this.sqlParam.limit;
			}
			this.clear();
			return this.query(sql);
		},

		drop : function(dbName){
			//          
			if(data){
				dbName = dbName || 'json_db';
				eval('Database.'+ dbName +'= null');
			}
			return this;
		},

		field : function(fields){
			if(typeof fields == 'object'){
				this.sqlParam.fields = fields.join(',');
			}else{
				this.sqlParam.fields = fields;
			}
			return this;
		},

		table : function(table){
			this.sqlParam.table = table;
			return this;
		},

		where : function(where){
			this.sqlParam.where = '('+where+')';
			return this;
		},

		order : function(order){
			this.sqlParam.order = order;
			return this;
		},
		
		limit : function(limit){
			this.sqlParam.limit = limit;
			return this;
		},

		clear : function(){
			this.sqlParam.fields = '*';
			this.sqlParam.where = null;
			this.sqlParam.order = null;
			this.sqlParam.limit = null;
		}
	}

	/**
	 * [DBCore      ]
	 */
	DBCore.fn = DBCore.prototype = {
		SqlRegExp : {
			fields: '([a-z0-9_\\,\\.\\s\\*]*?\\s+)',
			from : '(from\\s+([a-z0-9_\\.]+)\\s*)?',
			where : '(?:where\\s+(\\(.*\\))\\s*)?',
			order : '(?:order\\s+by\\s+([a-z0-9_\\,\\.]+))?\\s+(asc|desc|ascnum|descnum)?\\s*',
			limit : '(?:limit\\s+([0-9\\,]+))?',
			set : '(set\\s+(.*?)\\s+)',
			table : '(([a-z0-9_\\.]*?)\\s*)?',
		},

		select : function(sql){
			var params = {fields:["*"], from:"json_db", where:"", orderby:[], order: "asc", limit:[]},
			SqlRegExp = this.SqlRegExp,
			reg = '^(select)\\s+'+SqlRegExp.fields + SqlRegExp.from + SqlRegExp.where + SqlRegExp.order + SqlRegExp.limit,
			sqlReg = new RegExp(reg,'i'),
			sqlFields = sql.match(sqlReg),
			options = {
				fields: sqlFields[2].replace(' ','').split(','), 
				from: (sqlFields[4] == undefined) ? 'json_db' : sqlFields[4],
				where: (sqlFields[5] == undefined) ? "true" : sqlFields[5].replace(/([^\>\\\\= extent.start && tally < extent.stop){
							for(var j=0;j\\= extent.start && tally < extent.stop){
							eval('Database.'+options.from+'.splice(i-tally,1)');
							++tally;
						}else if(tally == extent.stop){
							return tally;
						}
						++affected_rows;
					}
				}
			}
			return tally;
		},

		filter : function(options, callback){
			var jsonData = eval('Database.' + options.from),
			result = [],
			index = 0;

			options.where = options.where || "true";
			for(var i in jsonData){
				with(jsonData[i]){
					if(eval(options.where)){
						if(callback){
							result[index++] = callback(jsonData[i]);
						}else{
							result[index++] = jsonData[i];
						}
					}
				}
			}
			
			return result;
		},

		orderBy : function(result,options){
			if(options.orderby.length == 0){
				return result;
			}
	
			result.sort(function(a,b){	
				switch(options.order.toLowerCase()){
					case "desc": return (eval('a.'+ options.orderby[0] +' < b.'+ options.orderby[0]))? 1:-1;
					case "asc":  return (eval('a.'+ options.orderby[0] +' > b.'+ options.orderby[0]))? 1:-1;
					case "descnum": return (eval('a.'+ options.orderby[0] +' - b.'+ options.orderby[0]));
					case "ascnum":  return (eval('b.'+ options.orderby[0] +' - a.'+ options.orderby[0]));
				}
			});
			
			return result;
		},

		limit : function(result,options){
			switch(options.limit.length){
				case 0: 
					return result;
				case 1: 
					return result.splice(0,options.limit[0]);
				case 2: 
					return result.splice(options.limit[0],options.limit[1]);
			}
		},

		extent : function(options){
			switch(options.limit.length){
				case 0: 
					return {start:0, stop:9e+99};
				case 1: 
					return {start:0, stop:options.limit[0]};
				case 2: 
					return {start:options.limit[0], stop:options.limit[1]};
			}
		}
	}

	window.jsonDB = jsonDB;

	//      
	jsonDB.fn = jsonDB.prototype =extend(jsonDB.fn,DBExpand);

	//      
	function extend(){
		var paramsLen = arguments.length;
		if(paramsLen<1){
			return false;
		}

		var target = arguments[0];
		for(var i=1;i