Converting varchar to monthDate

I'm receiving this error message: Conversion failed when converting the varchar value 'monthDate' to data type int.

I have this SQL statement:

String[][] results = lm.SqlSelect("SELECT COUNT(*) FROM members_ WHERE DATEPART(month, DateUnsub_) = 'monthDate' AND DATEPART(year, DateUnsub_) = 2011 AND DATEDIFF(day, DateJoined_, DateUnsub_) <= 30");

and I have an int here whose value changes depending on the dateLookup value:

switch (dateLookup)
        {
            case "January":
                monthDate = 01;
                break;
            case "February":
                monthDate = 02;
                break;
            case "March":
                monthDate = 03;
                break;
            case "April":
                monthDate = 04;
         开发者_开发问答       break;
            case "May":
                monthDate = 05;
                break;
            case "June":
                monthDate = 06;
                break;
            case "July":
                monthDate = 07;
                break;
            case "August":
                monthDate = 08;
                break;
            case "September":
                monthDate = 09;
                break;
            case "October":
                monthDate = 10;
                break;
            case "November":
                monthDate = 11;
                break;
            case "December":
                monthDate = 12;
                break;
        }

My question is - where is the varchar coming from? When I take the "monthDate" variable out of the SQL statement and replace it with the numbers 05, for example, everything works fine.

'monthDate' in your query string is not a variable.

I think it should be

String[][] results = lm.SqlSelect("SELECT COUNT(*) FROM members_ WHERE DATEPART(month, DateUnsub_) = " +monthDate + " AND DATEPART(year, DateUnsub_) = 2011 AND DATEDIFF(day, DateJoined_, DateUnsub_) <= 30");

Consider using string.Format() to make it more readable or better yet, parametrized command to protect against sql injection attacks.

your query is only selecting Count of the rows. you didn't select anything else as I look at your t-sql code.

after seeing your properties, please use the following code;

 switch (dateLookup)
    {
        case "January":
            monthDate = "01";
            break;
        case "February":
            monthDate = "02";
            break;
        case "March":
            monthDate = "03";
            break;
        case "April":
            monthDate = "04";
            break;
        case "May":
            monthDate = "05";
            break;

And so on. In English, put quotes before and after your numbers.