C# 然后做你的dataRow工作。但是你需要一个else,以防你找到空值。如果这样做,您必须找出要添加的列的类型,并相应地分配空值(即,如果类型为System.String,则可以分配String.Empty,但如果类型为System.Int16,则必须分配0
C# 然后做你的dataRow工作。但是你需要一个else,以防你找到空值。如果这样做,您必须找出要添加的列的类型,并相应地分配空值(即,如果类型为System.String,则可以分配String.Empty,但如果类型为System.Int16,则必须分配0,c#,.net,ado.net,C#,.net,Ado.net,然后做你的dataRow工作。但是你需要一个else,以防你找到空值。如果这样做,您必须找出要添加的列的类型,并相应地分配空值(即,如果类型为System.String,则可以分配String.Empty,但如果类型为System.Int16,则必须分配0(布尔字段)或者System.Decimal。重复问题:这里唯一的问题是,如果您在填充过程中发现列/值导致异常,它不会提供任何细节,就像您可以使用SqlDataReader获取并使用循环读取字段一样。这就是我花了一周时间寻找的! var dtW
然后做你的
dataRow
工作。但是你需要一个else
,以防你找到空值。如果这样做,您必须找出要添加的列的类型,并相应地分配空值(即,如果类型为System.String
,则可以分配String.Empty
,但如果类型为System.Int16
,则必须分配0
(布尔字段)或者System.Decimal
。重复问题:这里唯一的问题是,如果您在填充过程中发现列/值导致异常,它不会提供任何细节,就像您可以使用SqlDataReader
获取并使用循环读取字段一样。这就是我花了一周时间寻找的!
var dtWriteoffUpload = new DataTable();
dtWriteoffUpload.Columns.Add("Unit");
dtWriteoffUpload.Columns.Add("Year");
dtWriteoffUpload.Columns.Add("Period");
dtWriteoffUpload.Columns.Add("Acct");
dtWriteoffUpload.Columns.Add("Descr");
dtWriteoffUpload.Columns.Add("DEFERRAL_TYPE");
dtWriteoffUpload.Columns.Add("NDC_Indicator");
dtWriteoffUpload.Columns.Add("Mgmt Cd");
dtWriteoffUpload.Columns.Add("Prod");
dtWriteoffUpload.Columns.Add("Node");
dtWriteoffUpload.Columns.Add("Curve_Family");
dtWriteoffUpload.Columns.Add("Sum Amount");
dtWriteoffUpload.Columns.Add("Base Curr");
dtWriteoffUpload.Columns.Add("Ledger");
cmd = util.SqlConn.CreateCommand();
cmd.CommandTimeout = 1000;
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "proc_writeoff_data_details";
cmd.Parameters.Add("@whoAmI", SqlDbType.VarChar).Value =
WindowsIdentity.GetCurrent().Name;
cmd.Parameters.Add("@parmEndDateKey", SqlDbType.VarChar).Value = myMostRecentActualDate;
cmd.Parameters.Add("@countrykeys", SqlDbType.VarChar).Value = myCountryKey;
cmd.Parameters.Add("@nodekeys", SqlDbType.VarChar).Value = "1,2";
break;
dr = cmd.ExecuteReader();
while (dr.Read())
{
dtWriteoffUpload.Rows.Add(dr["country name"].ToString(), dr["country key"].ToString());
}
DataTable dt = new DataTable();
using (SqlConnection c = new SqlConnection(cString))
using (SqlDataAdapter sda = new SqlDataAdapter(sql, c))
{
sda.SelectCommand.CommandType = CommandType.StoredProcedure;
sda.SelectCommand.Parameters.AddWithValue("@parm1", val1);
...
sda.Fill(dt);
}
private void ConvertDataReaderToTableManually()
{
SqlConnection conn = null;
try
{
string connString = ConfigurationManager.ConnectionStrings["NorthwindConn"].ConnectionString;
conn = new SqlConnection(connString);
string query = "SELECT * FROM Customers";
SqlCommand cmd = new SqlCommand(query, conn);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection);
DataTable dtSchema = dr.GetSchemaTable();
DataTable dt = new DataTable();
// You can also use an ArrayList instead of List<>
List<DataColumn> listCols = new List<DataColumn>();
if (dtSchema != null)
{
foreach (DataRow drow in dtSchema.Rows)
{
string columnName = System.Convert.ToString(drow["ColumnName"]);
DataColumn column = new DataColumn(columnName, (Type)(drow["DataType"]));
column.Unique = (bool)drow["IsUnique"];
column.AllowDBNull = (bool)drow["AllowDBNull"];
column.AutoIncrement = (bool)drow["IsAutoIncrement"];
listCols.Add(column);
dt.Columns.Add(column);
}
}
// Read rows from DataReader and populate the DataTable
while (dr.Read())
{
DataRow dataRow = dt.NewRow();
for (int i = 0; i < listCols.Count; i++)
{
dataRow[((DataColumn)listCols[i])] = dr[i];
}
dt.Rows.Add(dataRow);
}
GridView2.DataSource = dt;
GridView2.DataBind();
}
catch (SqlException ex)
{
// handle error
}
catch (Exception ex)
{
// handle error
}
finally
{
conn.Close();
}
}
var dataReader = cmd.ExecuteReader();
var dataTable = new DataTable();
dataTable.Load(dataReader);
// Read every result set in the data reader.
while (!reader.IsClosed)
{
DataTable dt = new DataTable();
// DataTable.Load automatically advances the reader to the next result set
dt.Load(reader);
items.Add(dt);
}
[TestMethod]
public void SQLCommandVsAddaptor()
{
long AdapterFillLargeTableTime, readerLoadLargeTableTime, AdapterFillMediumTableTime, readerLoadMediumTableTime, AdapterFillSmallTableTime, readerLoadSmallTableTime, AdapterFillTinyTableTime, readerLoadTinyTableTime;
string LargeTableToFill = "select top 10000 * from FooBar";
string MediumTableToFill = "select top 1000 * from FooBar";
string SmallTableToFill = "select top 100 * from FooBar";
string TinyTableToFill = "select top 10 * from FooBar";
using (SqlConnection sconn = new SqlConnection("Data Source=.;initial catalog=Foo;persist security info=True; user id=bar;password=foobar;"))
{
// large data set measurements
AdapterFillLargeTableTime = MeasureExecutionTimeMethod(sconn, LargeTableToFill, ExecuteDataAdapterFillStep);
readerLoadLargeTableTime = MeasureExecutionTimeMethod(sconn, LargeTableToFill, ExecuteSqlReaderLoadStep);
// medium data set measurements
AdapterFillMediumTableTime = MeasureExecutionTimeMethod(sconn, MediumTableToFill, ExecuteDataAdapterFillStep);
readerLoadMediumTableTime = MeasureExecutionTimeMethod(sconn, MediumTableToFill, ExecuteSqlReaderLoadStep);
// small data set measurements
AdapterFillSmallTableTime = MeasureExecutionTimeMethod(sconn, SmallTableToFill, ExecuteDataAdapterFillStep);
readerLoadSmallTableTime = MeasureExecutionTimeMethod(sconn, SmallTableToFill, ExecuteSqlReaderLoadStep);
// tiny data set measurements
AdapterFillTinyTableTime = MeasureExecutionTimeMethod(sconn, TinyTableToFill, ExecuteDataAdapterFillStep);
readerLoadTinyTableTime = MeasureExecutionTimeMethod(sconn, TinyTableToFill, ExecuteSqlReaderLoadStep);
}
using (StreamWriter writer = new StreamWriter("result_sql_compare.txt"))
{
writer.WriteLine("10000 rows");
writer.WriteLine("Sql Data Adapter 100 times table fill speed 10000 rows: {0} milliseconds", AdapterFillLargeTableTime);
writer.WriteLine("Sql Data Reader 100 times table load speed 10000 rows: {0} milliseconds", readerLoadLargeTableTime);
writer.WriteLine("1000 rows");
writer.WriteLine("Sql Data Adapter 100 times table fill speed 1000 rows: {0} milliseconds", AdapterFillMediumTableTime);
writer.WriteLine("Sql Data Reader 100 times table load speed 1000 rows: {0} milliseconds", readerLoadMediumTableTime);
writer.WriteLine("100 rows");
writer.WriteLine("Sql Data Adapter 100 times table fill speed 100 rows: {0} milliseconds", AdapterFillSmallTableTime);
writer.WriteLine("Sql Data Reader 100 times table load speed 100 rows: {0} milliseconds", readerLoadSmallTableTime);
writer.WriteLine("10 rows");
writer.WriteLine("Sql Data Adapter 100 times table fill speed 10 rows: {0} milliseconds", AdapterFillTinyTableTime);
writer.WriteLine("Sql Data Reader 100 times table load speed 10 rows: {0} milliseconds", readerLoadTinyTableTime);
}
Process.Start("result_sql_compare.txt");
}
private long MeasureExecutionTimeMethod(SqlConnection conn, string query, Action<SqlConnection, string> Method)
{
long time; // know C#
// execute single read step outside measurement time, to warm up cache or whatever
Method(conn, query);
// start timing
time = Environment.TickCount;
for (int i = 0; i < 100; i++)
{
Method(conn, query);
}
// return time in milliseconds
return Environment.TickCount - time;
}
private void ExecuteDataAdapterFillStep(SqlConnection conn, string query)
{
DataTable tab = new DataTable();
conn.Open();
using (SqlDataAdapter comm = new SqlDataAdapter(query, conn))
{
// Adapter fill table function
comm.Fill(tab);
}
conn.Close();
}
private void ExecuteSqlReaderLoadStep(SqlConnection conn, string query)
{
DataTable tab = new DataTable();
conn.Open();
using (SqlCommand comm = new SqlCommand(query, conn))
{
using (SqlDataReader reader = comm.ExecuteReader())
{
// IDataReader Load function
tab.Load(reader);
}
}
conn.Close();
}
10000 rows:
Sql Data Adapter 100 times table fill speed 10000 rows: 11782 milliseconds
Sql Data Reader 100 times table load speed 10000 rows: 26047 milliseconds
1000 rows:
Sql Data Adapter 100 times table fill speed 1000 rows: 984 milliseconds
Sql Data Reader 100 times table load speed 1000 rows: 2031 milliseconds
100 rows:
Sql Data Adapter 100 times table fill speed 100 rows: 125 milliseconds
Sql Data Reader 100 times table load speed 100 rows: 235 milliseconds
10 rows:
Sql Data Adapter 100 times table fill speed 10 rows: 32 milliseconds
Sql Data Reader 100 times table load speed 10 rows: 93 milliseconds