How to get row value by just giving column name in DataTable

How to get row value by just giving column name in DataTable - c#

Is it possible to get a row value by giving column name when DataTable holds a single row, without iteration.
foreach(DataRow row in dt.Rows)
{
string strCity = row["City"].ToString();
}
Table
I need Something like below without loop when we have only one row,
String cn=row["ColumnName"].ToString()

This is the way:
string Text = dataTable.Rows[0]["ColumnName"].ToString();

Use following code to get the value of the first row of the DataTable without iteration:
string strCity = string.Empty;
if (yourDataTable.Rows.Count > 0)
strCity = yourDataTable.Rows[0]["City"].ToString();

Convert.ToString(row["ColumnName"]);

This is attempting to index the row itself:
row["ColumnName"].ToString()
What you're looking for is to index the items within the row:
row.Item["ColumnName"].ToString()
when DataTable holds a single row, without iteration
If you're guaranteed that there is a row, you can reference it directly:
dt.Rows[0].Item["ColumnName"].ToString()
As with any indexing, you should probably do some bounds checking before trying to index it though.

DataTable dt = new DataTable();
sqlDa.Fill(dt);
if (dt.Rows.Count > 0)
{
StringBuilder html = new StringBuilder();
foreach (DataRow row in dt.Rows)
{
html.Append(row.Field<Int32>("Columname"));
}
}

Related

Access DataTable row

I have a DataTable and I access its rows using a foreach loop
foreach (DataRow row in table.Rows)
{
userId = Convert.ToInt32(row[BundleSchema.ParamUpdatedBy]);
}
but knowing that my DataTable contains only a single row, how can I access it without looping through it?

You can use Index on Rows
DataRow row = table.Rows[0];
userId = Convert.ToInt32(row[BundleSchema.ParamUpdatedBy]);

ImportRow make the new row column missing

I want to copy all rows in old datatable (oldDT) to a new datatable (dt) using ImportRow method. But the new row doesn't have a same column with the old one. Here is my code:
foreach (DataRow dr in oldDT.Rows)
{
MessageBox.Show(dr["tenant_no"].ToString()); //giving a correct result
dt.ImportRow(dr);
MessageBox.Show(dt.Rows[0]["tenant_no"].ToString()); //giving an error Column 'tenant_no' does not belong to table .
}
i try to use the answer C# simple way to copy or clone a DataRow? and here is my new code:
foreach (DataRow dr in oldDT.Rows)
{
MessageBox.Show(dr["tenant_no"].ToString());
DataRow newDR = oldDT.NewRow();
newDR.ItemArray = dr.ItemArray.Clone() as object[];
dt.Rows.Add(newDR); //giving an error "This row already belongs to another table."
MessageBox.Show(dt.Rows[0]["tenant_no"].ToString());
}
Anyone can help me?

Try this... this will work
DataTable dt= new DataTable();
dt= oldDT.Clone();
for (int i=0;i < oldDT.Rows.Count; i++)
{
dt.ImportRow(dataTable.Rows[i]);
}

You could use DataTable.Copy, if you are not locked into using the ImportRow :
Copies both the structure and data for this DataTable.
DataTable dt = oldDt.Copy();

Exception in copying DataRow to another DataTable

I have two data tables, dt1 & dt2. dt1 has data while dt2 is a new table. Now I want to copy some rows, satisfying particular condition, to dt2. I have tried following code, but I get this exception:
System.ArgumentException This row already belongs to another table.
foreach(DataRow dr in dt1.Rows)
{
if(Convert.ToInt32(dr["col"]) == value)
{
dt2.Rows.Add(dr);
}
}
How can I resolve this?

change dt2.Rows.Add(dr); to dt2.Rows.Add(dr.ItemArray);

You directly cannot "Add" a DataTable row from one to another since it belongs to souce Datatable. You can "Add" a newly created row to DataTable.
Hence you are getting this exception.
There are many ways to overcome this. Some are listed below
Method 1:
If you want to get a row from source Datatable and add in destination without any changes, then use ImportRow this way.
dt2.ImportRow(dr);
Method 2:
But if you want to take specific data. Then use this
foreach(DataRow dr in dt1.Rows)
{
if(Convert.ToInt32(dr["col"]) == value)
{
Datarow ndr = dt2.NewRow();
ndr["Foo"] = dr["Foo"];
//..Similarly for other rows.
dt2.Rows.Add(ndr);
}
}

Every time when you add a row to the datatable it should be different(new) row........
Datarow newRow = null;
foreach(DataRow dr in dt1.Rows)
{
if(Convert.ToInt32(dr["col"]) == value)
{
newRow = dt2.NewRow();
newRow ["A"] = dr["A"];
dt2.Rows.Add(newRow );
}
}

Delete row from datatable where first column does not contain (some string)

I have DataTable with the following columns:
ClientID date numberOfTransactions price
ClientID is of type string and I need to ensure that its contents include "A-" and "N6" for every value in the table.
I need to delete all rows from the DataTable where this first column (ClientID) does not contain both "A-" and "N6" (some totals and other unnecessary data). How can I select and delete these rows specifically from the DataTable?
I know this:
foreach (DataRow row in table.Rows) // Loop over the rows.
{
//Here should come part "if first column contains mentioned values
}
I also know this
If (string.Contains("A-") == true && string.Contains("N6") == true)
{
//Do something
}
I need help how to implement this for first column of each row.

Try this:
EDIT: Totally messed up that last line, so if you tried it, try it now that I made it not stupid. =)
List<int> IndicesToRemove = new List<int>();
DataTable table = new DataTable(); //Obviously, your table will already exist at this point
foreach (DataRow row in table.Rows)
{
if (!(row["ClientID"].ToString().Contains("A-") && row["ClientID"].ToString().Contains("N6")))
IndicesToRemove.Add(table.Rows.IndexOf(row));
}
IndicesToRemove.Sort();
for (int i = IndicesToRemove.Count - 1; i >= 0; i--) table.Rows.RemoveAt(IndicesToRemove[i]);

try using this,
assuming dt as your Datatabe object and ClientID as your first column (hence using ItemArray[0])
for(int i=0; i<dt.Rows.Count; i++)
{
temp = dt.Rows[i].ItemArray[0].ToString();
if (System.Text.RegularExpressions.Regex.IsMatch(temp, "A-", System.Text.RegularExpressions.RegexOptions.IgnoreCase) || System.Text.RegularExpressions.Regex.IsMatch(temp, "N6", System.Text.RegularExpressions.RegexOptions.IgnoreCase))
{
dt.Rows.RemoveAt(i);
i--;
}
}
Simple and straight forward solution... hope it helps

this should be more efficient, both in lines of Code and Time, try this :)
for(int x=0; x<table.Rows.Count;)
{
if (!table.Rows[x].ItemArray[0].contains("A-") && !table.Rows[x].ItemArray[0].contains("N6"))
table.Rows.RemoveAt(x);
else x++;
}
Happy Coding

Preface: C.Barlow's existing answer is awesome, this is just another route someone could take.
This is one way to do it where you never have to loop all the way through the original table (by taking advantage of the DataTable.Select() method):
DataTable table = new DataTable(); // This would be your existing DataTable
// Grab only the rows that meet your criteria using the .Select() method
DataRow[] newRows = table.Select("ClientID LIKE '%A-%' AND ClientID LIKE '%N6%'");
// Create a new table with the same schema as your existing one.
DataTable newTable = table.Clone();
foreach (DataRow r in newRows)
{
// Dump the selected rows into the table.
newTable.LoadDataRow(r.ItemArray, true);
}
And now you have a DataTable with only the rows you want. If necessary, at this point you could clear out the original table and replace it with the contents of the new one:
table.Clear();
table = newTable.Copy();
Edit: I thought of a memory optimization last night, you can just overwrite the existing table once you have the rows you need, which avoids the need for the temporary table.
DataTable table = new DataTable(); // This would be your existing DataTable
// Grab only the rows that meet your criteria using the .Select() method
DataRow[] newRows = table.Select("ClientID LIKE '%A-%' AND ClientID LIKE '%N6%'");
// Clear out the old table
table.Clear();
foreach (DataRow r in newRows)
{
// Dump the selected rows into the table.
table.LoadDataRow(r.ItemArray, true);
}

Copy rows from one Datatable to another DataTable?

How can I copy specific rows from DataTable to another Datable in c#? There will be more than one row.

foreach (DataRow dr in dataTable1.Rows) {
if (/* some condition */)
dataTable2.Rows.Add(dr.ItemArray);
}
The above example assumes that dataTable1 and dataTable2 have the same number, type and order of columns.

Copy Specified Rows from Table to another
// here dttablenew is a new Table and dttableOld is table Which having the data
dttableNew = dttableOld.Clone();
foreach (DataRow drtableOld in dttableOld.Rows)
{
if (/*put some Condition */)
{
dtTableNew.ImportRow(drtableOld);
}
}

Try This
String matchString="ID0001"//assuming we have to find rows having key=ID0001
DataTable dtTarget = new DataTable();
dtTarget = dtSource.Clone();
DataRow[] rowsToCopy;
rowsToCopy = dtSource.Select("key='" + matchString + "'");
foreach (DataRow temp in rowsToCopy)
{
dtTarget.ImportRow(temp);
}

Check this out, you may like it (previously, please, clone table1 to table2):
table1.AsEnumerable().Take(recodCount).CopyToDataTable(table2,LoadOption.OverwriteChanges);
Or:
table1.AsEnumerable().Where ( yourcondition ) .CopyToDataTable(table2,LoadOption.OverwriteChanges);

Supported in: 4, 3.5 SP1, you can now just call a method on the object.
DataTable dataTable2 = dataTable1.Copy()

As a result of the other posts, this is the shortest I could get:
DataTable destTable = sourceTable.Clone();
sourceTable.AsEnumerable().Where(row => /* condition */ ).ToList().ForEach(row => destTable.ImportRow(row));

I've created an easy way to do this issue
DataTable newTable = oldtable.Clone();
for (int i = 0; i < oldtable.Rows.Count; i++)
{
DataRow drNew = newTable.NewRow();
drNew.ItemArray = oldtable.Rows[i].ItemArray;
newTable.Rows.Add(drNew);
}

I needed to copy rows from multiple tables with the same structure into a new table to be used as a datasource for datagridview:
// Generate DataTable[] alltables from multiple datatables
DataTable newTable = alltables[0].Clone();
foreach (DataTable dt in alltables)
{
for (int i = 0; i < dt.Rows.Count; i++)
newTable.Rows.Add(dt.Rows[i].ItemArray);
}

below sample would be the fastest way to copy one row.
each cell is being copied based on the column name.
in case you dont need a specific cell to copy then have a try catch or add if.
if your going to copy more than 1 row then loop the code below.
DataRow dr = dataset1.Tables[0].NewRow();
for (int i = 0; i < dataset1.Tables[1].Columns.Count; i++)
{
dr[dataset1.Tables[1].Columns[i].ColumnName] = dataset1.Tables[1].Rows[0][i];
}
datasetReport.Tables[0].Rows.Add(dr);
dataset1.Tables[1].Rows[0][i]; change the index 0 to your specified row index or you can use a variable if your going to loop or if its going to be logical

private void CopyDataTable(DataTable table){
// Create an object variable for the copy.
DataTable copyDataTable;
copyDataTable = table.Copy();
// Insert code to work with the copy.
}

To copy whole datatable just do this:
DataGridView sourceGrid = this.dataGridView1;
DataGridView targetGrid = this.dataGridView2;
targetGrid.DataSource = sourceGrid.DataSource;

For those who want single command SQL query for that:
INSERT INTO TABLE002
(COL001_MEM_ID, COL002_MEM_NAME, COL002_MEM_ADD, COL002_CREATE_USER_C, COL002_CREATE_S)
SELECT COL001_MEM_ID, COL001_MEM_NAME, COL001_MEM_ADD, COL001_CREATE_USER_C, COL001_CREATE_S
FROM TABLE001;
This query will copy data from TABLE001 to TABLE002 and we assume that both columns had different column names.
Column names are mapped one-to-one like:
COL001_MEM_ID -> COL001_MEM_ID
COL001_MEM_NAME -> COL002_MEM_NAME
COL001_MEM_ADD -> COL002_MEM_ADD
COL001_CREATE_USER_C -> COL002_CREATE_USER_C
COL002_CREATE_S -> COL002_CREATE_S
You can also specify where clause, if you need some condition.

There is better way to do this.
DataTable targetDataTable = new DataTable();
targetDataTable = changedColumnMetadata.AsEnumerable().Where(dataRow => entityName.Equals(dataRow["EntityName"])).CopyToDataTable();
Please try this and let me know in case of any issues.

You can do it calling the DataTable.Copy() method, for example:
DataSet ds = new DataSet();
System.Data.DataTable dt = new System.Data.DataTable();
dt = _BOSearchView.DS.Tables[BusLib.TPV.TableName.SearchView].Copy();
ds.Tables.Add(dt);
UltGrdSaleExcel.SetDataBinding(ds, dt.TableName, true);

use Merge, this will append all rows of newDataTable with oldDateTale
oldDateTale.Merge(newDataTable);

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.

How to get row value by just giving column name in DataTable - c#

Is it possible to get a row value by giving column name when DataTable holds a single row, without iteration. foreach(DataRow row in dt.Rows) { string strCity = row["City"].ToString(); } Table I need Something like below without loop when we have only one row, String cn=row["ColumnName"].ToString()

This is the way: string Text = dataTable.Rows[0]["ColumnName"].ToString();

Use following code to get the value of the first row of the DataTable without iteration: string strCity = string.Empty; if (yourDataTable.Rows.Count > 0) strCity = yourDataTable.Rows[0]["City"].ToString();

Convert.ToString(row["ColumnName"]);

DataTable dt = new DataTable(); sqlDa.Fill(dt); if (dt.Rows.Count > 0) { StringBuilder html = new StringBuilder(); foreach (DataRow row in dt.Rows) { html.Append(row.Field<Int32>("Columname")); } }

Related

Access DataTable row

ImportRow make the new row column missing

Exception in copying DataRow to another DataTable

Delete row from datatable where first column does not contain (some string)

Copy rows from one Datatable to another DataTable?

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