CODEWITHSUNDEEP
c#sqlasp.netsql-server-2016
user8951186
user8951186

Reputation:

SQL Server print statement returning null in Data Table

I am authenticating account using if exists query and print true if the account is authenticate else print false.

if exists (select email, password 
           from client 
           where email = '[email protected]' and password = '123') 
    print 'true' 
else 
    print 'false';

It prints true or false in SQL Server Management Studio, but when I authenticate account from my website, the data table rows and columns count is always 0. What is the problem, and how can I fix it?

public bool ExecuteReader(string query)
{
        bool result = false;

        SqlConnection con = new SqlConnection(ConnectionString);
        con.Open();

        SqlDataAdapter da = new SqlDataAdapter();
        da.SelectCommand = new SqlCommand(query, con);
        con.Close();

        dt = new DataTable();
        da.Fill(dt);

        if (dt.Rows.Count == 1 && dt.Columns.Count == 1)
        {
            if (dt.Rows[0][0].ToString() == "true")
            {
                result = true;
            }
            else
            {
                result = false;
            }
        }

        return result;
    }

Upvotes: 0

Views: 262

Answers (3)

RoMEoMusTDiE
RoMEoMusTDiE

Reputation: 4824

try this one and also the close code after the everything is done.

SELECT
  ISNULL((SELECT
    'true'
  FROM client
  WHERE email = '[email protected]'
  AND password = '123')
  , 'false')

Upvotes: 0

Abel Fontes
Abel Fontes

Reputation: 1

You query uses print 'true' else print 'false'. The print statement does not return a row of data; use select 'true' else select 'false' instead.

In addition, you are closing the connection before executing the command which fills the data table; try moving the con.Close() after the da.Fill(dt).

Upvotes: 0

Dan Guzman
Dan Guzman

Reputation: 46213

PRINT returns a message rather than a result set (which requires a SqlConnection.InfoMessage event handler). USE a SELECT statement instead to load the result into a DataTable:

IF EXISTS(SELECT 1
FROM dbo.client
WHERE email = '[email protected]' AND password = '123'
)
SELECT 'true'
ELSE
SELECT 'false';

Upvotes: 2

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