public int InsertPerson(DataRow newper) 
{ 
            switch(dbtype) 
            { 
                case 0: //sqlserver 
                  sql="insert into() values()"; 
                  break;
                case 1: //mysql 
                  sql="insert into() values()"; 
                  break; 
            } 
            return this.icon.ExecuteInsert(sql);
}

------解决方案--------------------
可以这样：
C# code

public int InsertPerson(DataRow newper) 
        { 
int ret=-1;
            switch(dbtype) 
            { 
                case 0: //sqlserver 
                  sql="insert into() values()"; 
                  ret=this.icon.ExecuteInsert(sql); 
                  break;
                case 1: //mysql 
                  sql="insert into() values()"; 
                  ret=this.icon.ExecuteInsert(sql); 
                  break;
          } 
      return ret;  //请问return 的值该怎么写啊?多谢~~ 
}

------解决方案--------------------
C# code
        public int ExecuteInsert(string argSqlInsert) 
        { 
            SqlCommand sqlExecuteCommand = new SqlCommand(argSqlInsert, dbConnection); 
            if (dbTrans != null) 
                sqlExecuteCommand.Transaction = dbTrans; 
            object ret = sqlExecuteCommand.ExecuteScalar(); 
            return (int)ret; 
        } 

public int InsertPerson(DataRow newper) 
{ 
            switch(dbtype) 
            { 
                case 0: //sqlserver 
                  sql="insert into() values()"; 
                  break;
                case 1: //mysql 
                  sql="insert into() values()"; 
                  break; 
            } 
            return this.icon.ExecuteInsert(sql);
}

------解决方案--------------------
C# code

public int InsertPerson(DataRow newper) 
        {
           object myObject=new Object();
            switch(dbtype) 
            { 
                case 0: //sqlserver 
                  sql="insert into() values()"; 
                  myObject=this.icon.ExecuteInsert(sql); //接收ExcecuteInsert(sql)的结果
                case 1: //mysql 
                  sql="insert into() values()"; 
                  myObject=this.ic