Adding bool column in DataTable with value

Question

i try to add column in datatable :

dt.Columns.Add(new DataColumn("BoolProperty", typeof(bool)));

and try to set value - false:

DataRow dr = dt.NewRow();
dr["BoolProperty"] = false;

But it does not work! Here is code:

try
{
    con.server = this.server;
    con.user = this.user;
    con.password = this.password;
    con.OpenConnection();
    con.SqlQuery(Properties.Resources.databaseCatalogResource);
    DataTable dt = con.QueryEx();
    con.da.Fill(dt);
    dt.Columns.Add(new DataColumn("BoolProperty", typeof(bool)));
    DataRow dr = dt.NewRow();
    dr["BoolProperty"] = false;
    dataGrid.ItemsSource = dt.DefaultView;

}
catch (Exception ex)
{
    MessageBox.Show("Грешка във връзката.", "Грешка");
}

This is what happens :

but i need this column to be unchecked.

Remove the try catch (or actually show the error in the catch) so you can see what's going wrong — EpicKip
– EpicKip, Commented Aug 17, 2017 at 7:31
Do you need to add this boolean values for all rows in the table or need to add a new(last) row with this boolean? — sujith karivelil
– sujith karivelil, Commented Aug 17, 2017 at 7:35

ASh · Accepted Answer · 2017-08-17 07:53:00Z

4

create a boolean dataColumn with a default value false before filling data. (A default value is the value that is automatically assigned to the column when a DataRow is created)

DataTable dt = con.QueryEx();
var column = new DataColumn("BoolProperty", typeof(bool));
column.DefaultValue = false;
dt.Columns.Add(column);
con.da.Fill(dt);

lines

DataRow dr = dt.NewRow();
dr["BoolProperty"] = false;

are basically useless. dr is a new empty row, isn't added to a table and doesn't change flags in other rows

edited Aug 17, 2017 at 7:53

answered Aug 17, 2017 at 7:37

ASh

35.9k9 gold badges68 silver badges89 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Ravikumar · Accepted Answer · 2017-08-17 07:38:07Z

1

Try this

dt.Columns.Add(new DataColumn("BoolProperty", typeof(bool)));
for (int i=0;i<dt.Rows.Count;i++)
{
  dt.Rows[i]["BoolProperty"] = "Split";
}

answered Aug 17, 2017 at 7:38

Ravikumar

6251 gold badge9 silver badges22 bronze badges

Comments

sujith karivelil · Accepted Answer · 2017-08-17 07:40:43Z

1

So the DataTable dt is already filled with some values from the database using con.da.Fill(dt);, and you are adding a new column to this populated table. If you need to add value to this column means you have to do something like this:

// Your code
dt.Columns.Add(new DataColumn("BoolProperty", typeof(bool)));
foreach(DataRow dr in dt.Rows)
{
    dr["BoolProperty"] = false;
}

Or simply include false as BoolProperty in your query that fills the datatable, Which will add a last column in the DataTable in all fetched rows with false

answered Aug 17, 2017 at 7:40

sujith karivelil

29.1k7 gold badges60 silver badges90 bronze badges

Comments

PaulG · Accepted Answer · 2018-04-24 10:28:53Z

0

Most of the answers here loop through the rows to set the default value, but it can also be done inline by using the override of Columns.Add that takes an expression parameter

For example, to set all rows to boolean true:

dt.Columns.Add(new DataColumn("BoolProperty", typeof(bool), "true"));

You can also use the expression parameter to set the column value based on other values in the row, which might look something like

dt.Columns.Add(new DataColumn("BoolProperty", typeof(bool), "price > 50"));

Worth noting though, that adding an expression based column like this also makes the column read-only, as it is intended not to be altered based on (eg) user input.

answered Apr 24, 2018 at 10:28

PaulG

14.1k9 gold badges61 silver badges83 bronze badges

Comments

sprash · Accepted Answer · 2019-04-03 05:05:51Z

0

Use:

DataTable.Columns.Add(new DataColumn("Column Name", typeof(bool), true.ToString())

DataColumn has a constructor overload as above. Here it accepts the third parameter as default value for that DataColumn. But the parameter is of string type. So make sure that the default value is typecasted to string.

P.S. I solved this same problem for me using above way.

answered Apr 3, 2019 at 5:05

sprash

3633 silver badges18 bronze badges

Collectives™ on Stack Overflow

Adding bool column in DataTable with value

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related