Coding (cari dari 2 atau lebih kategori) pada VB

Dim str As String

        'str yang akan di isi

        'cari 4 kategori

        If Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%' or pengarang like '%" & tbpengarangcari.Text & "%' or penerbit like '%" & tbpenerbitcari.Text & "%' or bag like '%" & tbbagiancari.Text & "%'"

            'cari 3 kategori

        ElseIf Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length <= 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%' or pengarang like '%" & tbpengarangcari.Text & "%' or penerbit like '%" & tbpenerbitcari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length <= 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%' or pengarang like '%" & tbpengarangcari.Text & "%' or bag like '%" & tbbagiancari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length <= 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where pengarang like '%" & tbpengarangcari.Text & "%' or penerbit like '%" & tbpenerbitcari.Text & "%' or bag like '%" & tbbagiancari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length <= 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%' or penerbit like '%" & tbpenerbitcari.Text & "%' or bag like '%" & tbbagiancari.Text & "%'"

            'cari 2 kategori

            'awal 1

        ElseIf Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length <= 0 And Me.tbbagiancari.Text.Length <= 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%' or pengarang like '%" & tbpengarangcari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length <= 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length <= 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%' or penerbit like '%" & tbpenerbitcari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length <= 0 And Me.tbpenerbitcari.Text.Length <= 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%' or bagian like '%" & tbbagiancari.Text & "%'"

            'awal 2

        ElseIf Me.tbjudulcari.Text.Length <= 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length <= 0 Then

            str = "select * from tbbuku where pengarang like '%" & tbpenerbitcari.Text & "%' or penerbit like '%" & tbpenerbitcari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length <= 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length <= 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where pengarang like '%" & tbpengarangcari.Text & "%' or bagian like '%" & tbbagiancari.Text & "%'"

            'awal 3

        ElseIf Me.tbjudulcari.Text.Length <= 0 And Me.tbpengarangcari.Text.Length <= 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where penerbit like '%" & tbpenerbitcari.Text & "%' or bag like '%" & tbbagiancari.Text & "%'"

            'cari 1 kategori

        ElseIf Me.tbjudulcari.Text.Length > 0 And Me.tbpengarangcari.Text.Length <= 0 And Me.tbpenerbitcari.Text.Length <= 0 And Me.tbbagiancari.Text.Length <= 0 Then

            str = "select * from tbbuku where judul like '%" & tbjudulcari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length <= 0 And Me.tbpengarangcari.Text.Length > 0 And Me.tbpenerbitcari.Text.Length <= 0 And Me.tbbagiancari.Text.Length <= 0 Then

            str = "select * from tbbuku where pengarang like '%" & tbpengarangcari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length <= 0 And Me.tbpengarangcari.Text.Length <= 0 And Me.tbpenerbitcari.Text.Length > 0 And Me.tbbagiancari.Text.Length <= 0 Then

            str = "select * from tbbuku where penerbit like '%" & tbpenerbitcari.Text & "%'"

        ElseIf Me.tbjudulcari.Text.Length <= 0 And Me.tbpengarangcari.Text.Length <= 0 And Me.tbpenerbitcari.Text.Length <= 0 And Me.tbbagiancari.Text.Length > 0 Then

            str = "select * from tbbuku where bag like '%" & tbbagiancari.Text & "%'"

        End If

        'str belum di isi, kondisi str NULL, kondisi str di atas terpenuhi