C＃查询表达式中的语法错误（缺少运算符）

Question

string sqlStatement = "select ID, Checkintime, RoomPrice, OrderNo from Orders where RoomType='" + selectedRoom.Key + "' and RoomNumber=" + selectedRoom.Value + " and Checkintime>="+dateOnly+" and CheckinTime<'"+endingTime+"'"; 

myAccessCommand = new OleDbCommand(sqlStatement, myAccessConn);
OleDbDataAdapter myDataAdapter = new OleDbDataAdapter(myAccessCommand);
myDataAdapter.Fill(myDataSet, "Orders");

I have syntax error in the SQL statement line but I am not sure what went wrong that caused an syntax exception.

Answer 1

Short fix: change

Checkintime>="+dateOnly+" 

to

Checkintime>='"+dateOnly+"'

(you forgot the tick marks in the first reference to Checkintime )

Much better: Use a parameterized query