How to delete all rows from datatable

Question

I want to delete all rows from datatable with rowstate property value Deleted.

DataTable dt;
dt.Clear(); // this will not set rowstate property to delete.

Currently I am iterating through all rows and deleting each row.

Is there any efficient way? I don't want to delete in SQL Server I want to use DataTable method.

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Answer 1

We are using this way:

for(int i = table.Rows.Count - 1; i >= 0; i--) {
    DataRow row = table.Rows[i];
    if ( row.RowState == DataRowState.Deleted ) { table.Rows.RemoveAt(i); }
}

Answer 2

This will satisfy any FK cascade relationships, like 'delete' (that DataTable.Clear() will not):

DataTable dt = ...;
// Remove all
while(dt.Count > 0)
{
     dt.Rows[0].Delete();
}

Answer 3

dt.Rows.Clear();
dt.Columns.Clear();   //warning: All Columns delete
dt.Dispose();

Answer 4

由于您使用的是 SQL Server 数据库，因此我主张简单地执行 SQL 命令"DELETE FROM " + dt.TableName 。

Answer 5

I would drop the table, fastest way to delete everything. Then recreate the table.

Answer 6

您可以在 SQL Server db 上创建一个存储过程，删除表中的所有行，从 C# 代码中执行它，然后重新查询数据表。

Answer 7

我通常执行以下 SQL 命令：

DELETE FROM TABLE WHERE ID>0

Answer 8

I want to delete all rows from datatable with rowstate property value Deleted.

DataTable dt;
dt.Clear(); // this will not set rowstate property to delete.

Currently I am iterating through all rows and deleting each row.

Is there any efficient way? I don't want to delete in SQL Server I want to use DataTable method.

---

Answer 9

Here is the solution that I settled on in my own code after searching for this question, taking inspiration from Jorge's answer.

DataTable RemoveRowsTable = ...;
int i=0;
//Remove All
while (i < RemoveRowsTable.Rows.Count)
{
     DataRow currentRow = RemoveRowsTable.Rows[i];
     if (currentRow.RowState != DataRowState.Deleted)
     {
         currentRow.Delete();
     }
     else
     {
         i++;
     }
}

This way, you ensure all rows either get deleted, or have their DataRowState set to Deleted.

Also, you won't get the InvalidOperationException due to modifying a collection while enumerating, because foreach isn't used. However, the infinite loop bug that Jorge's solution is vulnerable to isn't a problem here because the code will increment past a DataRow whose DataRowState has already been set to Deleted.