G
Guest
Hi All
Does anyone know how can I select some column from a datatable
Chung
Does anyone know how can I select some column from a datatable
Chung
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W
William Ryan eMVP
Hi Chung:
What do you mean by Select? You can reference a column in a DataTable via
it's .Columns property ie myDataTable.Columns[0] would give you the first
column in the table, (Or you can reference it by name, so if column 0 was
named "User_Name") you could reference myDataTable.Columns["User_Name"];
Where possible, use the numeric index instead b/c it's a lot faster (for
instance, if you were iterating through 10000 rows you'd probably see a
notable performance difference). or you can use Bill Vaughn's cool method
and use an enum.
Now, if you are talking about a column in context of a row you could use
foreach(DataRow dro in myDataTable.Rows){
string s = (string)dro[0];
}
There is also a .Select method but I'm guessing that's not what you're
after.
Let me know if I didn't answer it and I'll do what I can.
HTH,
Bill
www.devbuzz.com
www.knowdotnet.com
Chung said:Hi All,
Does anyone know how can I select some column from a datatable?
Chung
What do you mean by Select? You can reference a column in a DataTable via
it's .Columns property ie myDataTable.Columns[0] would give you the first
column in the table, (Or you can reference it by name, so if column 0 was
named "User_Name") you could reference myDataTable.Columns["User_Name"];
Where possible, use the numeric index instead b/c it's a lot faster (for
instance, if you were iterating through 10000 rows you'd probably see a
notable performance difference). or you can use Bill Vaughn's cool method
and use an enum.
Now, if you are talking about a column in context of a row you could use
foreach(DataRow dro in myDataTable.Rows){
string s = (string)dro[0];
}
There is also a .Select method but I'm guessing that's not what you're
after.
Let me know if I didn't answer it and I'll do what I can.
HTH,
Bill
www.devbuzz.com
www.knowdotnet.com
G
Guest
----- William Ryan eMVP wrote: ----
Hi Chung
What do you mean by Select? You can reference a column in a DataTable vi
it's .Columns property ie myDataTable.Columns[0] would give you the firs
column in the table, (Or you can reference it by name, so if column 0 wa
named "User_Name") you could reference myDataTable.Columns["User_Name"]
Where possible, use the numeric index instead b/c it's a lot faster (fo
instance, if you were iterating through 10000 rows you'd probably see
notable performance difference). or you can use Bill Vaughn's cool metho
and use an enum
Now, if you are talking about a column in context of a row you could us
foreach(DataRow dro in myDataTable.Rows)
string s = (string)dro[0]
There is also a .Select method but I'm guessing that's not what you'r
after
Let me know if I didn't answer it and I'll do what I can
HTH
Bil
www.devbuzz.co
www.knowdotnet.co
Hi Bill
Thank you for your quick respones
I think I have to make my question more clear. What I mean is within the DotNet framework, any fast function which can select some of the column from a datatable by passing a query statement. Like (Select column_01, column_02 from Datatable)
I know that we can use DataSet.Tables[0].Select("ID=10") to get all the datarow which contains ID=10, but it will return all the datacolumn from the datatable. Do you know any function can select some of the datacolumn from a datatable
Chun
Hi Chung
Chung said:Hi All
What do you mean by Select? You can reference a column in a DataTable vi
it's .Columns property ie myDataTable.Columns[0] would give you the firs
column in the table, (Or you can reference it by name, so if column 0 wa
named "User_Name") you could reference myDataTable.Columns["User_Name"]
Where possible, use the numeric index instead b/c it's a lot faster (fo
instance, if you were iterating through 10000 rows you'd probably see
notable performance difference). or you can use Bill Vaughn's cool metho
and use an enum
Now, if you are talking about a column in context of a row you could us
foreach(DataRow dro in myDataTable.Rows)
string s = (string)dro[0]
There is also a .Select method but I'm guessing that's not what you'r
after
Let me know if I didn't answer it and I'll do what I can
HTH
Bil
www.devbuzz.co
www.knowdotnet.co
Hi Bill
Thank you for your quick respones
I think I have to make my question more clear. What I mean is within the DotNet framework, any fast function which can select some of the column from a datatable by passing a query statement. Like (Select column_01, column_02 from Datatable)
I know that we can use DataSet.Tables[0].Select("ID=10") to get all the datarow which contains ID=10, but it will return all the datacolumn from the datatable. Do you know any function can select some of the datacolumn from a datatable
Chun
W
William Ryan eMVP
Not as such, but you can reference the affected columns specifically so that
shouldn't be a big deal. Remember that columns are just pieces in a
collection so you can reference those directlly.
HTH,
Bill
from a datatable by passing a query statement. Like (Select column_01,
column_02 from Datatable).
datatable. Do you know any function can select some of the datacolumn from a
datatable.
shouldn't be a big deal. Remember that columns are just pieces in a
collection so you can reference those directlly.
HTH,
Bill
the DotNet framework, any fast function which can select some of the columnChung said:----- William Ryan eMVP wrote: -----
Hi Chung:
Chung said:Hi All,
What do you mean by Select? You can reference a column in a DataTable via
it's .Columns property ie myDataTable.Columns[0] would give you the first
column in the table, (Or you can reference it by name, so if column 0 was
named "User_Name") you could reference myDataTable.Columns["User_Name"];
Where possible, use the numeric index instead b/c it's a lot faster (for
instance, if you were iterating through 10000 rows you'd probably see a
notable performance difference). or you can use Bill Vaughn's cool method
and use an enum.
Now, if you are talking about a column in context of a row you could use
foreach(DataRow dro in myDataTable.Rows){
string s = (string)dro[0];
}
There is also a .Select method but I'm guessing that's not what you're
after.
Let me know if I didn't answer it and I'll do what I can.
HTH,
Bill
www.devbuzz.com
www.knowdotnet.com
Hi Bill,
Thank you for your quick respones.
I think I have to make my question more clear. What I mean is within
from a datatable by passing a query statement. Like (Select column_01,
column_02 from Datatable).
datarow which contains ID=10, but it will return all the datacolumn from theI know that we can use DataSet.Tables[0].Select("ID=10") to get all the
datatable. Do you know any function can select some of the datacolumn from a
datatable.