That's the easiest way to delete all rows from the table in dbms via DataAdapter
. But if you want to do it in one batch, you can set the DataAdapter's UpdateBatchSize
to 0(unlimited).
Another way would be to use a simple SqlCommand
with CommandText DELETE FROM Table
:
using(var con = new SqlConnection(ConfigurationSettings.AppSettings["con"]))
using(var cmd = new SqlCommand())
{
cmd.CommandText = "DELETE FROM Table";
cmd.Connection = con;
con.Open();
int numberDeleted = cmd.ExecuteNonQuery(); // all rows deleted
}
But if you instead only want to remove the DataRows
from the DataTable
, you just have to call DataTable.Clear
. That would prevent any rows from being deleted in dbms.
If you are really concerned about speed and not worried about the data you can do a Truncate. But this is assuming your DataTable is on a database and not just a memory object.
TRUNCATE TABLE tablename
The difference is this removes all rows without logging the row deletes making the transaction faster.
Just use dt.Clear()
Also you can set your TableAdapter/DataAdapter to clear before it fills with data.
This will allow you to clear all the rows and maintain the format of the DataTable
.
dt.Rows.Clear();
There is also
dt.Clear();
However, calling Clear()
on the DataTable
(dt
) will remove the Columns and formatting from the DataTable.
Per code found in an MSDN question, an internal method is called by both the DataRowsCollection
, and DataTable
with a different boolean
parameter:
internal void Clear(bool clearAll)
{
if (clearAll) // true is sent from the Data Table call
{
for (int i = 0; i < this.recordCapacity; i++)
{
this.rows[i] = null;
}
int count = this.table.columnCollection.Count;
for (int j = 0; j < count; j++)
{
DataColumn column = this.table.columnCollection[j];
for (int k = 0; k < this.recordCapacity; k++)
{
column.FreeRecord(k);
}
}
this.lastFreeRecord = 0;
this.freeRecordList.Clear();
}
else // False is sent from the DataRow Collection
{
this.freeRecordList.Capacity = this.freeRecordList.Count + this.table.Rows.Count;
for (int m = 0; m < this.recordCapacity; m++)
{
if ((this.rows[m] != null) && (this.rows[m].rowID != -1))
{
int record = m;
this.FreeRecord(ref record);
}
}
}
}
As someone mentioned, just use:
dt.Rows.Clear()
Datatable.clear()
method from class DataTable
Is there a Clear() method on the DataTable class??
I think there is. If there is, use that.
Why dont you just do it in SQL?
DELETE FROM SomeTable
Here is a clean and modern way to do it using Entity FW and without SQL Injection or TSQL..
using (Entities dbe = new Entities())
{
dbe.myTable.RemoveRange(dbe.myTable.ToList());
dbe.SaveChanges();
}
I using MDaf just use this code :
DataContext db = new DataContext(ConfigurationManager.ConnectionStrings["con"].ConnectionString);
db.TruncateTable("TABLE_NAME_HERE");
//or
db.Execute("TRUNCATE TABLE TABLE_NAME_HERE ");
Here we have same question. You can use the following code:
SqlConnection con = new SqlConnection();
con.ConnectionString = ConfigurationManager.ConnectionStrings["yourconnectionstringnamehere"].ConnectionString;
con.Open();
SqlCommand com = new SqlCommand();
com.Connection = con;
com.CommandText = "DELETE FROM [tablenamehere]";
SqlDataReader data = com.ExecuteReader();
con.Close();
But before you need to import following code to your project:
using System.Configuration;
using System.Data.SqlClient;
This is the specific part of the code that can delete all rows is a table:
DELETE FROM [tablenamehere]
This must be your table name:tablenamehere
- This can delete all rows in table: DELETE FROM
Source: Stackoverflow.com