Question

Hello I am getting this error –

‘Error converting data type nvarchar to bigint’

while running this is the code:

string idString = "1,2,3,4";

string updateSql = "UPDATE DistinctClubcard SET ProcessedYorN = 'Y' " + "WHERE CLUBCARD_NUMBER in (@flag) ";

SqlCommand UpdateCmd = new SqlCommand(updateSql, cn);
UpdateCmd.Parameters.Add(new SqlParameter("@flag", SqlDbType.NVarChar, 2000));
UpdateCmd.Parameters["@flag"].Value = idString ;
UpdateCmd.ExecuteNonQuery();

Answer 1

This won’t work – A SQL IN (...) query needs an array of sql parameters, it will not just work with passing a single string parameter. Instead use a separate parameter for each value and an array of integer values:

string idString = "1,2,3,4";
var ids = idString.Split(',').Select(x => int.Parse(x)).ToArray();

for(int i =0;i< ids.Length;i++)
{
  UpdateCmd.Parameters.Add(new SqlParameter("@flag"+i, SqlDbType.BigInt));
  UpdateCmd.Parameters["@flag"+i].Value = ids[i];
}

Of course that also changes your query where you have to account for your parameters:

string flags =  string.Join(",", ids.Select((s, i) => "@flag" + i));
string updateSql = string.Format("UPDATE DistinctClubcard SET ProcessedYorN = 'Y' WHERE CLUBCARD_NUMBER in ({0})",flags);