Selection using dapper

Question

I have a problem with my query using dapper, whether someone imagine to help me and say where I'm doing the wrong, is currently showing me an error at the date when I put a breik point, how to correct it properly? thank you all for help

this is my current code

public string GetBezeichnung(int LP, DateTime date)
{
    using (IDbConnection connection = new System.Data.SqlClient.SqlConnection())
    {
        connection.ConnectionString = _ConnectionString;
        var output = connection.Query<string>("SELECT ZER_Bezeichnung FROM Z_ERFASSUNG WHERE ZER_LPE = " + LP + " AND ZER_Datum = " + date).FirstOrDefault();
        return output;
    }
}

and this is the result with which I get an error

Answer 1

Try parameterizing the query.

public string GetBezeichnung(int LP, DateTime date)
{
    using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(_ConnectionString))
    {
        connection.Open();
        string sql = @"
SELECT ZER_Bezeichnung 
FROM Z_ERFASSUNG 
WHERE ZER_LPE = @LP
  AND ZER_Datum = @date"
        var output = connection.Query<string>(sql, new { LP = LP, date = date }).FirstOrDefault();
        return output;
    }
}

Answer 2

I agree with @Parrish Husband, but the Second Paramater has to be "Date = date".

In your example there are no ' around the date so AQL thinks its a bunch or things.

Changing it to

var output = connection.Query<string>("SELECT ZER_Bezeichnung FROM Z_ERFASSUNG WHERE ZER_LPE = " + LP + " AND ZER_Datum = '" + date + "'").FirstOrDefault();

will make it work.