We Keep Coding

Searching DataTable with string containing space c#

So I've done a lot of searching for this one and can't figure it out. I have a csv file that i'm writing off to a DataTable and populating a combo box from that same datatable. The Idea is to search a user selected value in the data table and return the ID of that selection from the same data table. The problem I'm having is that the selections all have spaces since they are capacity environments. Is there a way to take the string and search the datatable column "Description" and return the column "ID"? here is the code:
internal static void envRequest(string e)
{
DataRow[] foundRows;
foundRows = variables.capEnvTable.Select(e);
//variables.envID = foundRows[0].ToString();
Thread.Sleep(200);
Console.WriteLine(foundRows.ToString());
}
}
The DataTable is formated as "ID" - "Name" - "Description"
The value of e is the user selected value such as "Buckeye Hosting Zone 2 Aries"
Right now I'm getting a System.Data.SyntaxErrorException: 'Syntax error: Missing operand after 'Hosting' operator.' on the
foundRows = variables.capEnvTable.Select(e);

Ok lets say the first column (index 0) is the value you want to search and the 2nd column (index 1) is the value you want.
DataRow dataRow;
dataRow =
myDataGridView.Rows.Cast<DataRow>()
.FirstOrDefault( row => row[0] == "ValueYouWantToSearch" );
var value = dataRow[1];

how to get a last column value in a Templorary datatable (.net)

I am storing some values in a temporary datatable.Sample values as follows
ID FILENAME PATH
--------------------------
1 txt1 C:\NewFolder
2 txt2 C:\NewFolder
3 txt3 C:\NewFolder
I want to get the last value of ID column.

You can use such code to get the last row and then the value from column ID:
object lastId = table.Rows[table.Rows.Count-1]["ID"];
If by last you meant that you need the maximum value from the table you can use the following LINQ query to get the result:
int maxValue= table.AsEnumerable().Select(row => Convert.ToInt32(row["ID"])).Max();
You need to have the following using in order for it to work:
using System.Data.DataSetExtensions;

string expression = "1=1"
// Sort descending by column named CompanyName.
string sortOrder = "ID DESC";
DataRow[] foundRows;
// Use the Select method to find all rows matching the filter.
foundRows = table.Select(expression, sortOrder);
var row = foundRows[0];
Ref:https://msdn.microsoft.com/en-us/library/way3dy9w(v=vs.110).aspx

Column abc does not belong to table?

I am iterating a DataTable in my C# code. I try to get the contents using of a column named "columnName" of row named "row" using -
object value = row["ColumnName"];
I get this error -
Error: System.Reflection.TargetInvocationException: Exception has been
thrown by the target of an invocation.
---> System.ArgumentException: Column 'FULL_COUNT' does not belong to table . at System.Data.DataRow.GetDataColumn(String columnName)
How is this possible ? My SQL query/result set has a column by that name and the query even runs in management studio.
How do I fix this error ?

I am guessing your code is iteration supposed to be something like this
DataTable table = new DataTable();
foreach (DataRow row in table.Rows) {
foreach (DataColumn col in table.Columns) {
object value = row[col.ColumnName];
}
}
If this is the case, row["ColumnName"] in each iteration looks for the same column with name ColumnName which obviously does not exists in your table.
The correct way is row[ColumnName] or row[col.ColumnName] in iteration above

I had a similar issue on my c# code, using a dataset which I had successfully initialized and populated with data from the DB.
So my return set was:
data = new Byte[0];
data = (Byte[])(dataset.Tables[0].Rows[0]["systemLogo_img"]);
Of course the error was in t finding the column 'systemLogo_img'.
I noted that you simply do NOT have to call /qualify the column name. So the correction is:
data = new Byte[0];
data = (Byte[])(dataset.Tables[0].Rows[0].ItemArray[0]);
Simply put: use "ItemArray" at position.
Thanks

Do not write Gridview column names instead of Database column names.
dataGridViewEmployeeClass.Rows[n].Cells[0].Value = item["write the Database Column names"].ToString();

Try this, make sure your column name is same
DataTable dt = new DataTable();
dt.Columns.Add("abc", typeof(string));
DataRow dr = dt.NewRow();
dr["abc"]="";

I had a similar issue which was very basic to fix.
I was querying with a specific column name rather than Select * (i.e. Select Title). Beginner's error but happens to everyone.

If you want to check if the column exists in the DataRow before accessing the value the following block can help...
if (dataRow.Table.Columns.Contains("theColumnName"))
{
// do work
string text = string.Empty;
if (dataRow["theColumnName"] != System.DBNull.Value)
{
text = Convert.ToString(dataRow["theColumnName"]);
}
}
If it doesn't exist and it needs to be added to the data table you can add the column using #Karthick Ganesan's example
// add a column
dataTable.Columns.Add("theColumnName", typeof(string));

I had same issue was trying to pass two different keys for same product.
item.Product = SqlHelper.GetSafeString(dr, "ProductName");
item.Product = SqlHelper.GetSafeString(dr, "Product");

C# Datatable woes

I have a database command that populates a DataTable I want to get the value of an entry in the Datatable, based on, A: The numeral index of the row, and b, the string name of the column. That's all I want, how is that possible?

yourDatatable.Rows[rowIndex]["columnName"] should work

myTbl.Rows[0]["b"];
A is not a row index.

DataTable dt = GetData();
var result = dt.Rows[RowIndex]["MyColumnName"];
The RowIndex is an indexed property of the datatable which returns a DataRow. "MyColumnName" is an indexed property of the DataRow, returning the value as an object.

Convert datarow to int

I have a datarow, but how can i convert it to an int ?
I tried this, but it doesn't work.
dsMovie = (DataSet)wsMovie.getKlantId();
tabel = dsMovie.Tables["tbl_klanten"];
eersteRij = tabel.Rows[0];
(Int32.Parse(eersteRij.ToString())

A DataRow is an object; it is not an integer. A DataRow contains one or more columns of data. You can index into the DataRow to access the values of these coulmns.
If table tbl_klanten contains one column, and that column is an integer, you can do the following:
var myInt = (int)eersteRij[0];
if the column is a string containing the value of an integer,
var myInt = int.Parse(eersteRij[0]);
If the column is named klant_id...
var myInt = (int)eersteRij["klant_id"];
if the column is a string containing the value of an integer,
var myInt = int.Parse(eersteRij["klant_id"]);

Simply use the Field method:
int result = row.Field<int>("ColName");
The Field method also supports nullable types:
The Field method provides support for accessing columns as nullable
types. If the underlying value in the DataSet is Value, the returned
nullable type will have a value of null.
And please notice:
The Field method does not perform type conversions. If type conversion is required, you should first obtain the column value by using the Field method. The column value should then be converted to another type.

Because even at that level of hierarchy you still have a DataRow and you can't convert a DataRow to int.. a value could be converted though.
And why are you converting whole DataRow to int.. usually you would like to get a value in a cell at a row so try, Somthing like this:
int value = (int)eersteRij.Items[0];
where 0 can be replaced by the cell position(int) or Column name(string)

You'll need to know which index the object you want is on, and cast that to an int, e.g.:
int value = (int)eersteRij[0];

DataSet dataSet = getDataFromDatabase();
DataRow tableRow = dataSet.Tables[0].Rows[0];
int valueAsInteger = Convert.ToInt32(tableRow["COLUMN_NAME"]);

I tend to use IndexOf() when looping thru the dataTable.
foreach (DataRow row in DataTable.table.Rows)
{
int index = dataTable.Rows.IndexOf(row);
}