Parameter Add in SQL from Oracle Database with C#

In my SQL select part i have column like this;

NVL(RISK_SASI(A.TEKLIF_NO1, A.TEKLIF_NO2, C.URUN_SIRA_NO, C.SIRA_NO, :S_DATE),0) AS RISK

And I adding dinamicly with a TextBox this S_DATE value.

string txtBoxText1 = ((TextBox)Page.FindControl("TextBox1")).Text;
if (txtBoxText1 != "")
dt_stb = DateTime.Parse(txtBoxText1);
myCommand.Parameters.AddWithValue(":S_TARIH_B", dt_stb);

BUT it didn't work for my SQL.

Here is mine full SQL;

SELECT A.HESAP_NO, A.TEKLIF_NO1 || '/' || A.TEKLIF_NO2 AS TEKLIF, A.MUS_K_ISIM AS MUSTERI, 
                    B.MARKA, C.SASI_NO, C.SASI_DURUM, D.TAS开发者_StackOverflow社区_MAR, NVL(RISK_SASI(A.TEKLIF_NO1, A.TEKLIF_NO2, C.URUN_SIRA_NO, C.SIRA_NO, :S_TARIH_B),0) AS RISK,
                    NVL(MV_SASI(A.TEKLIF_NO1, A.TEKLIF_NO2, C.SIRA_NO, C.URUN_SIRA_NO, :S_TARIH_B),0) AS MV,
                    MV_K(A.TEKLIF_NO1,A.TEKLIF_NO2, :S_TARIH_B) AS KV
                    FROM S_TEKLIF A,  S_URUN B, S_URUN_DETAY C, KOC_KTMAR_PR D
                    WHERE A.TEKLIF_NO1 || A.TEKLIF_NO2 = B.TEKLIF_NO1 || B.TEKLIF_NO2
                    AND A.TEKLIF_NO1 || A.TEKLIF_NO2 = C.TEKLIF_NO1 || C.TEKLIF_NO2
                    AND B.SIRA_NO = C.URUN_SIRA_NO
                    AND B.DISTRIBUTOR = D.DIST_KOD
                    AND B.MARKA = D.MARKA_KOD
                    AND B.URUN_KOD = D.TAS_KOD

How can i do that?

Best Regards, Soner

When using parameters with ORACLE, you'd have to use @ instead of :. I recently asked a question about how to make this generic in code. You might want to have a look at it: DbCommand and parameterized SQL, ORACLE vs SQL Server