Database

string connstr = String.Format("DATABASE ={0};UID=db2admin;PWD=db2admin", DBName.Trim());
DB2Connection conn = new DB2Connection(connstr);
DB2Parameter[] paras = new DB2Parameter[]{new DB2Parameter("@SNAPSHOTTIMESTAMP",DB2Type.Date),
                                          new DB2Parameter("@DATABASESIZE",DB2Type.BigInt),
                                          new DB2Parameter("@DATABASECAPACITY",DB2Type.BigInt)

             };
             paras[0].Value = DBNull.Value;
             paras[1].Value = DBNull.Value;
             paras[2].Value = DBNull.Value;

             paras[0].Direction = ParameterDirection.Output;
             paras[1].Direction = ParameterDirection.Output;
             paras[2].Direction = ParameterDirection.Output;

             conn.Open();
             DB2Command com = new DB2Command("GET_DBSIZE_INFO", conn);
             com.CommandType = CommandType.StoredProcedure;
             com.Parameters.AddRange(paras);// = paras;
             com.ExecuteNonQuery();
             DBSizeInfo sizeinf = new DBSizeInfo();
             sizeinf.Size = (int)paras[1].Value;
             sizeinf.Capacity = (int)paras[2].Value;
             conn.Close();

using System;
using System.Data;
using System.Data.SqlClient;

namespace DataSetTest
{
    class Program
    {
        static void Main(string[] args)
        {
            DataSet ds = GetDataSet();
            SqlConnection conn = new SqlConnection("Server=DEVRDABTS01\\MSDEVPARA;database=sandbox; Integrated Security=SSPI");
            conn.Open();

            SqlCommand comm = new SqlCommand("usp_DatasetTest_Insert", conn);
            comm.CommandType = CommandType.StoredProcedure;

            SqlDataAdapter da = new SqlDataAdapter();
            da.InsertCommand = comm;

            da.Update(ds); //<---- Error here
        }

        public static DataSet GetDataSet()
        {
            DataSet returnDS = new DataSet();
            DataTable dt = returnDS.Tables.Add("DatasetTest");

            dt.Columns.Add("dateValue", typeof(DateTime));
            dt.Columns.Add("clientId", typeof(string));
            dt.Columns.Add("stringValue", typeof(string));
            dt.Columns.Add("dontInsertIfNull", typeof(string));

            DataRow dr;

            for (int i = 0; i < 10; ++i)
            {
                dr = dt.NewRow();

                dr[0] = DateTime.Now;
                dr[1] = i.ToString();
                dr[2] = "some string";
                dr[3] = (i % 2) == 0 ? "" : "this is not null";

                //dr.SetAdded();

                dt.Rows.Add(dr);
            }

            return returnDS;
        }
    }
}

Declare @stepid int

set @stepid = 1 --change to 2 after you have run the export

if @stepid = 1
    create table vendorbak (DCLink int, Account nvarchar(1000), Name nvarchar(1000))
    select DCLink, Account, Name into VendorBak from Vendor where CT = 0
    update Vendor set CT = 1

if @stepid = 2
    update Vendor set CT = 0 from VendorBak vb where Vendor.DCLink = vb.DCLink
    drop table vendorbak