What is wrong with my query in asp.net? - asp.net

Question

I am trying to fill a gridview by taking data from multiple tables. Here is my code:
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = Userfunctions.GetConnectionString();
con.Open();
string query = "SELECT RegisterTable.CourseCode,
RegisterTable.courseNumber,
RegisterTable.Term,RegisterTable.Grade,
CourseTable.CourseName,
CourseTable.Level,
CourseTable.Credit
FROM RegisterTable,CourseTable
WHERE StudentID='" + MyGlobals.currentID + "' and
RegisterTable.CourseCode=CourseTable.CourseCode and
RegisterTable.CourseNumber=CourseTable.CourseNumber and
RegisterTable.Term=CourseTable.Term";
SqlDataAdapter adap = new SqlDataAdapter(query, con);
DataTable tab = new DataTable();
adap.Fill(tab);
GridView1.DataSource = tab;
GridView1.DataBind();
}
This gives an error saying that "Incorrect syntax near the keyword 'where'." Can anyone help me with this? Thanks
EDIT:
Ignore the string's lack of concatenation. It was all on one line and you had to scroll for a mile to see it all. They just made it easier to see.

Answer 1

Have you tried re-writing your query (so it's not using a cross-join)?
protected void Page_Load(object sender, EventArgs e)
{
SqlConnection con = null;
SqlCommand cmd = null;
SqlDataAdapter adap = null;
string query = string.Empty();
DataSet ds = null;
DataTable tab = null;
con = new SqlConnection();
con.ConnectionString = Userfunctions.GetConnectionString();
query = "SELECT RegisterTable.CourseCode, RegisterTable.CourseNumber, RegisterTable.Term, RegisterTable.Grade, CourseTable.CourseName, CourseTable.Level, CourseTable.Credit FROM RegisterTable INNER JOIN CourseTable ON RegisterTable.CourseCode = CourseTable.CourseCode AND RegisterTable.CourseNumber = CourseTable.CourseNumber AND RegisterTable.Term = CourseTable.Term WHERE StudentID = #StudentID;";
cmd = new SqlCommand(query, con);
cmd.Parameters.Add("StudentID", SqlDbType.VarChar, 50).Value = MyGlobals.currentID;
ds = new DataSet();
adap = new SqlDataAdapter(cmd);
adap.Fill(ds);
if (ds.Tables.Count > 0) {
tab = ds.Tables(0);
}
GridView1.DataSource = tab;
GridView1.DataBind();
}