通用数据库操作类库，实现一种统一的基础SQL语法，可以翻译到不同类型的数据库中执行，从而无需为不同的数据库书写不同的操作指令。

//HOW TO USE?

        string sql =

               @"if 1>2{select switch(a){1:'aaa',2:'bbb',default:null}}else if(2>3)select switch(b){1:111,2:222,default:555}else select switch(b){1:111,2:222,default:555};declare @wwww varchar(12);select a.* ,a.dd,a,ff,12 as ddd,b.* as d from a,(select * from c) as b join c on a.f1==c.f1 left join d on d.f1==c.f1 full join (select * from table1) as f on a.f2==f.f2 where a.id==1 and exists(select * from gg) group by a.id,a.id1,a.id2 having b.ggggg==d.ggg order by a.id asc,b.id desc union all select * from xxxxx limit 2,10 delete t1 from t1,t2 join s on s.f1==t1.f1 where t1.f2='xxxxx' INSERT INTO TABLE1(F1,F2,F3)VALUES(12,45,'333') INSERT INTO TABLE2 VALUES(1,2,3,4,'5') UPDATE TABLE3 SET F1=@PARA,F2=12 * 45+45 * MAX(1,2,3,4,5) WHERE TABLE3.ID==2 ";

        TSQLParser SP = new TSQLParser(sql); 
        
        List<IStatement> l = SP.ReadStatements();//得到解析后的语法树
        
        MsSql ms = new MsSql("Data Source=.;User ID=sa;Password=123456;");
        
        string tsql = ms.Setting().Generate(l.ToArray());//将语法树翻译到对应的目标数据库，得到适用的SQL指令