一个ASP（JScript）简单SQL语句构建“类”

<%@language="javascript" codepage="936"%><%var queststringbuilder = function(){    // 1->查问语句, 2->革新语句, 3->简略语句, 4->插入语句    var questtype = 0;    var fields = [];    var values = [];    var condition;    var pk;    var pkeysort;    var tablename;    var state = false;    var clogic = " and ";    var coperator = "=";    this.addfield = function(field,value){        fields.push(processfield(field));        values.push(processvalue(value));    };    this.addcfield = function(cfield,cvalue){        var stemp = [];        if(condition!=undefined&&condition!=""){ stemp.push(condition); }        if(coperator!="like"){            stemp.push(processfield(cfield)+coperator+processvalue(cvalue));        }else{            stemp.push(processfield(cfield)+" like '%"+cvalue+"%'");                    }        condition = stemp.join(clogic);        if(condition==""){ condition=stemp.tostring();}    };    this.table = function(s){tablename = s;};    this.pkey = function(s){pk = processfield(s);};    this.pkeyasc = function(){pkeysort="asc";};    this.pkeydesc = function(){pkeysort="desc";};    this.getselect = function(){        questtype = 1;        return result();    };    this.getupdate = function(){        questtype = 2;        return result();    };    this.getdelete = function(){        questtype = 3;        return result();    };    this.getinsert = function(){        questtype = 4;        return result();    };    this.clear = function(){        fields = [];        values = [];        pk = undefined;        pkeysort = undefined;        tablename = undefined;        state = false;    };    this.actionstate = function(){ return state;};    this.changelogic = function(s){ clogic = " "+s.touppercase()+" ";};    this.changeoperator = function(s){coperator = s.touppercase();};    var result = function(){        var strtemp;        if(fields.length==0) fields.push("*");        switch(questtype){            case 1:                if(tablename!=undefined&&tablename!=""){                    strtemp = "select " + fields.tostring() + " from " + tablename;                    if(condition!=undefined){ strtemp += " where " + condition;}                    if(pkeysort!=undefined&&pk!=undefined){ strtemp += " order by " + pk + " " + pkeysort;}                    state = true;                }else{                    strtemp = geterror(0); // 诉求输出表名                }                return strtemp;                break;            case 2:                if(tablename!=undefined&&tablename!=""){                    strtemp = "update " + tablename + " set " + process(fields,values) ;                    if(condition!=undefined){                        state = true;                        strtemp += " where " + condition;                    }else{                        strtemp = geterror(1);                    }                }else{                    strtemp = geterror(0); // 诉求输出表名                }                                return strtemp;                break;            case 3:                if(tablename!=undefined&&tablename!=""){                    strtemp = "delete from " + tablename ;                    if(condition!=undefined){                        state = true;                        strtemp += " where " + condition;                    }else{                        strtemp = geterror(1);                    }                }else{                    strtemp = geterror(0); // 诉求输出表名                }                                return strtemp;                break;            case 4:                if(tablename!=undefined&&tablename!=""){                    strtemp = "insert into " + tablename ;                    if(fields.length!=0){                        state = true;                        strtemp += "(" + fields.tostring() + ") values(" + values.tostring() + ")";                    }else{                        strtemp = geterror(2);                    }                }else{                    strtemp = geterror(0); // 诉求输出表名                }                                return strtemp;                break;        }    };    var processvalue = function(unknow){        var inputtype = typeof(unknow);        switch(inputtype){            case "string":                return "'"+unknow+"'";                break;            case "number":                return unknow;                break;            case "boolean":                return unknow;                break;        }    };    var processfield = function(unknow){        return "["+unknow+"]";    };    var process = function(afield,avalue){        var atemp = [];        for(i=0;i<afield.length;i++){            atemp.push(afield[i]+"="+avalue[i]);        }        return atemp.tostring();    }    var geterror = function(interror){        if(typeof(interror)=="number"){            switch(interror){                case 0:                    state = false;                    return "need quest tablename, please using method table input one tablename!";                    break;                case 1:                    state = false;                    return "need one condition! please using method addcfield add condition!";                    break;                case 2:                    state = false;                    return "need insert values!";                    break;            }        }    };};var sql = new queststringbuilder();sql.table("mytable");sql.addfield("test","1");sql.addfield("test1",23);sql.addcfield("id",93);sql.pkey("id");sql.pkeydesc();//sql.clear();response.write(sql.getdelete()+"<br>"+sql.actionstate());%>