C# guid and SQL uniqueidentifier

Here's a code snippet showing how to insert a GUID using a parameterised query:

    using(SqlConnection conn = new SqlConnection(connectionString))
    {
        conn.Open();
        using(SqlTransaction trans = conn.BeginTransaction())
        using (SqlCommand cmd = conn.CreateCommand())
        {
            cmd.Transaction = trans;
            cmd.CommandText = @"INSERT INTO [MYTABLE] ([GuidValue]) VALUE @guidValue;";
            cmd.Parameters.AddWithValue("@guidValue", Guid.NewGuid());
            cmd.ExecuteNonQuery();
            trans.Commit();
        }
    }

SQL is expecting the GUID as a string. The following in C# returns a string Sql is expecting.

"'" + Guid.NewGuid().ToString() + "'"

Something like

INSERT INTO TABLE (GuidID) VALUE ('4b5e95a7-745a-462f-ae53-709a8583700a')

is what it should look like in SQL.


You can pass a C# Guid value directly to a SQL Stored Procedure by specifying SqlDbType.UniqueIdentifier.

Your method may look like this (provided that your only parameter is the Guid):

public static void StoreGuid(Guid guid)
{
    using (var cnx = new SqlConnection("YourDataBaseConnectionString"))
    using (var cmd = new SqlCommand {
        Connection = cnx,
        CommandType = CommandType.StoredProcedure,
        CommandText = "StoreGuid",
        Parameters = {
            new SqlParameter {
                ParameterName = "@guid",
                SqlDbType = SqlDbType.UniqueIdentifier, // right here
                Value = guid
            }
        }
    })
    {
        cnx.Open();
        cmd.ExecuteNonQuery();
    }
}

See also: SQL Server's uniqueidentifier