how to query my data using multiple textboxes - sql

Question

i have textboxes called classno 1 to 8
i have a code like this:
Dim sqlQuery As String = "SELECT ClassNo, SubjectCode, Title, Lec, Lab, Days,
TimeSlot, roomNo, Ins_ID
from studSched WHERE SubjectCode = '" & classno1.Text & "' and '" & classno2.Text & "' and '" & classno3.Text &
"' AND'" & classno4.Text & "' AND'" & classno5.Text & "' AND '" & classno6.Text & "' AND'" & classno7.Text & "' AND'" & classno8.Text & "' "
where textbox classno 1 to 8 have a value of subject 1 to 8
ex:
classno1="subject1"
how to query all textboxes in my access
my probelem is it will get all data in my access,
how to get all specific data in my access..
i need a code of my query..

Answer 1

I think you need this
Dim sqlQuery As String = "SELECT ClassNo, SubjectCode, Title, Lec,
Lab, Days,TimeSlot, roomNo, Ins_ID
FROM studSched
WHERE SubjectCode = '" & classno1.Text & "' AND
SubjectCode = '" & classno2.Text & "' AND
SubjectCode = '" & classno3.Text & "' AND
SubjectCode = '" & classno4.Text & "' AND
SubjectCode = '" & classno5.Text & "' AND
SubjectCode = '" & classno6.Text & "' AND
SubjectCode = '" & classno7.Text & "' AND
SubjectCode = '" & classno8.Text & "' "
And this is not recommended, Use Parameterized Query
Dim Cmd as New SqlCommand()
cmd.Connection = con
cmd.CommandText = "SELECT ClassNo, SubjectCode, Title, Lec,Lab, Days,TimeSlot, roomNo,Ins_ID
FROM studSched WHERE SubjectCode = #Sub1 AND SubjectCode = #Sub2 AND
SubjectCode = #Sub3 AND SubjectCode = #Sub4 AND
SubjectCode = #Sub5 AND SubjectCode = #Sub6 AND
SubjectCode = #Sub7 AND SubjectCode = #Sub8"
cmd.Parameters.AddWithValue("#Sub1", classno1.Text)
cmd.Parameters.AddWithValue("#Sub2", classno2.Text)
cmd.Parameters.AddWithValue("#Sub3", classno3.Text)
cmd.Parameters.AddWithValue("#Sub4", classno4.Text)
cmd.Parameters.AddWithValue("#Sub5", classno5.Text)
cmd.Parameters.AddWithValue("#Sub6", classno6.Text)
cmd.Parameters.AddWithValue("#Sub7", classno7.Text)
cmd.Parameters.AddWithValue("#Sub8", classno8.Text)