Question

I have a query in SQL Server 2008.

SELECT
    CONVERT(char(80), i.InvDate,3) AS InvDate,
    i.InvoiceNo,
    i.TaxAmount + i.SubTotal AS Amount,
    '' AS Payment,
    pd.GivenName
FROM
dbo.Invoice i
    INNER JOIN dbo.PatientDetails pd ON (pd.MedicalRecordID = i.MedicalRecordID)
    WHERE (InvDate >= CONVERT(datetime, '16/10/2012', 105)) AND 
(InvDate <= CONVERT(datetime, '16/10/2012', 105))

---

Output:

When i tried to put that into C#, it says “Conversion failed when converting date and/or time from character string.”

---

Info: 16/10/2012 are sample dates which i tried to insert into the query to make sure it runs. It’s a old program, thats why its converting from a string. I’m pretty sure its something gotta do with the datetime format. Had a look at http://www.sqlusa.com/bestpractices/datetimeconversion/. But i cant put a finger through it.

SqlCommand objCmd = new SqlCommand("SELECT CONVERT(char(80), i.InvDate,3) 

AS InvDate,

i.InvoiceNo, i.TaxAmount + i.SubTotal AS Amount,'' AS Payment,pd.GivenName 

FROM

dbo.Invoice i INNER JOIN dbo.PatientDetails pd

ON 
(pd.MedicalRecordID = i.MedicalRecordID)

WHERE

(InvDate >= CONVERT(datetime, 'dd/MM/yyyy', 105)) 

AND 

(InvDate <= CONVERT(datetime, 'dd/MM/yyyy', 105))", objConn);



        SqlDataReader objReader;
        objReader = objCmd.ExecuteReader();

        System.IO.FileStream fs = new System.IO.FileStream("C:\\CMSExportedData\\Sales-" + 
DateTime.Now.ToString("dd-MM-yyyy") + ".txt", System.IO.FileMode.Create);
        System.IO.StreamWriter sw = new System.IO.StreamWriter(fs,   
System.Text.Encoding.Default);

Answer 1

CONVERT(datetime, 'dd/MM/yyyy', 105) is attempting to convert the literal text dd/MM/yyyy into a datetime – that’s never going to work.

SqlCommand objCmd = new SqlCommand(@"SELECT CONVERT(char(80), i.InvDate,3) 
AS InvDate,
i.InvoiceNo, i.TaxAmount + i.SubTotal AS Amount,'' AS Payment,pd.GivenName 
FROM
dbo.Invoice i INNER JOIN dbo.PatientDetails pd
ON 
(pd.MedicalRecordID = i.MedicalRecordID)
WHERE
(InvDate >= @StartDate) 
AND 
(InvDate <= @EndDate)", objConn);

objCmd.Parameters.AddWithValue("@StartDate",/* some C# expression that gives you the start date, as a DateTime value */);
objCmd.Parameters.AddWithValue("@EndDate",/* some C# expression that gives you the end date, as a DateTime value */);

You’ll have to fill in the commented parts in the last two lines above. At a guess, from your previous question, they might be dtpFrom.Value and dtpTo.Value.