Update multiple rows in datatable without loop

Question

I have two datatable with conditions in application and want some processing for multiple rows to update column value.

For example:

I have datatable1 with 10000 rows. I want to filter rows by datatable.select("condition") and as per condition, I want to update row values.

If for any condition, I found 20 rows from datatable. I want to update those 20 records in one shot. Not in any loop. I have datarow array for those values to update in datable.

How exactly do you want to update the rows? This seems like something you could probably do with a dynamic query using the ``in`` keyword. — Kippie, Sep 16 '13 at 14:11
How do you think you can do it without a loop? If framework provides some method also it will be internally doing a loop! — Sriram Sakthivel, Sep 16 '13 at 14:11
maybe he means with lambda expressions.. but there will be anyway a loop — darkdog, Sep 16 '13 at 14:16
@Sriram - Yes, I know but better way or anything or any method which I am not aware if! Thats the reason I posted question. — k-s, Sep 16 '13 at 14:19
@darkdog - Thanks for your understanding. Something similar I am looking for. — k-s, Sep 16 '13 at 14:19

score 11 · Accepted Answer · answered Sep 16 '13 at 14:16

11

You can try out the following linq,

DataTable recTable = new DataTable();

// do stuff to populate table

recTable.Select(string.Format("[code] = '{0}'", someName)).ToList<DataRow>().ForEach(r => r["Color"] = colorValue);

You can substitute your columns and values here...

answered Sep 16 '13 at 14:16

Rajesh Subramanian

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Loop is far far efficient than this – Sriram Sakthivel Sep 16 '13 at 14:21
this is just a way to update without using loops externally. if performance is a constraint, then go for Parallel For. – Rajesh Subramanian Sep 16 '13 at 14:24
Thanks for inputs and suggestions. – k-s Sep 16 '13 at 14:26
string.Format("[Code]='{0}'",somename) what is code here and what is somename. are you updating the value of code – Anjali Jul 16 '14 at 02:56

sivabalan · Answer 2 · 2014-08-20T08:04:30.097

2

To Update Row With Multiple Condition use This

    datatable.Select(string.Format("[lineNo]='{0}' and [Position]>='{1}' ", lineNo, Position)).ToList<DataRow>().ForEach(r => r["Linetext"] ="Sample Text" );

edited Aug 20 '14 at 08:04

answered Aug 20 '14 at 07:48

sivabalan

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This is just a fancier way of still doing a loop - Note the 'ForEach(...)' – Ryan Tirrell Dec 31 '20 at 11:44

score 0 · Answer 3 · answered Mar 28 '17 at 17:27

If you want to default a column value with abc use Expression, then you could use the below code.

dt.Columns.Add("ColumnName").Expression = "'abc'";

In case if you need to pass the value dynamically using a variable, you could use the below code.

string str = "abc";
dt.Columns.Add("ColumnName").Expression = "'" + str + "'";

Update multiple rows in datatable without loop

3 Answers3

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