C# 向数据表添加列并添加数据
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时间：2020-08-10 11:28:23 来源:igfitidea点击:
Adding a column to a datatable and adding data
提问by Arianule
How can I add a column to a datatable and add data to each row based on a condition. This is what I am trying to do
如何将一列添加到数据表并根据条件将数据添加到每一行。这就是我想要做的
conn = new OleDbConnection(@"Provider=Microsoft.Jet.OleDb.4.0;
Data Source =" + Server.MapPath("App_Data\LR Product Database 2000.mdb"));
conn.Open();
Dictionary<string, string> items = new Dictionary<string, string>();
OleDbCommand cmd = conn.CreateCommand();
cmd.CommandText = "SELECT CODE, TITLE FROM tblProducts";
OleDbDataReader dbread = cmd.ExecuteReader();
while (dbread.Read())
{
productCode = (string)dbread["ProductCode"];
productTitle = items[productCode];
items.Add(productCode, productTitle);
}
sqlCon = new SqlConnection(ConfigurationManager.ConnectionStrings["LRVWebsite"].ToString());
sqlCon.Open();
dsSql = new DataSet();
SqlDataAdapter dba = new SqlDataAdapter(@"SELECT C.CustomerFirstName,C.CustomerLastName, C.CustomerCompany,C.CustomerPosition,C.CustomerCountry,C.CustomerProvince,C.CustomerContact,CP.ActionDate,CP.ProductCode,CP.CustomerEmail FROM tblCustomers C INNER JOIN tblCustomerProducts CP ON C.CustomerEmail = CP.CustomerEmail ORDER BY ActionDate DESC", connString);
dba.Fill(dsSql,"Products");
DataTable dt = dsSql.Tables["Products"];
foreach (DataRow dr in dt.Rows)
{
for (int i = 0; i < items.Count; i++)
{
if (dr["ProductCode"].ToString().Equals(productCode))
{
//here I want to add a new column and add data (productTitle) to the column
}
}
}
采纳答案by Daniel W.
dba.Fill(dsSql,"Products");
DataTable dt = dsSql.Tables["Products"];
dt.Columns.Add("ColumnName", typeof(DataType));
if (dr["ProductCode"].ToString().Equals(productCode))
{
dr["ColumnName"] = value;
}
Further i would extend the code to avoid NullReferenceException
此外，我会扩展代码以避免 NullReferenceException
if (!String.IsNullOrEmpty(dr["ProductCode"]) && dr["ProductCode"].ToString().Equals(productCode))
{
dr["ColumnName"] = value;
}
