CODEWITHSUNDEEP
c#datatable
valterriann
valterriann

Reputation: 1281

Check if value exists in dataTable?

I have DataTable with two columns Author and Bookname.

I want to check if the given string value Author already exists in the DataTable. Is there some built in method to check it, like for Arrays array.contains?

Upvotes: 107

Views: 325293

Answers (5)

Tim Schmelter
Tim Schmelter

Reputation: 460028

You can use LINQ-to-DataSet with Enumerable.Any:

String author = "John Grisham";
bool contains = tbl.AsEnumerable().Any(row => author == row.Field<String>("Author"));

Another approach is to use DataTable.Select:

DataRow[] foundAuthors = tbl.Select("Author = '" + searchAuthor + "'");
if(foundAuthors.Length != 0)
{
    // do something...
}

Q: what if we do not know the columns Headers and we want to find if any cell value PEPSI exist in any rows'c columns? I can loop it all to find out but is there a better way? –

Yes, you can use this query:

DataColumn[] columns = tbl.Columns.Cast<DataColumn>().ToArray();
bool anyFieldContainsPepsi = tbl.AsEnumerable()
    .Any(row => columns.Any(col => row[col].ToString() == "PEPSI"));

Upvotes: 240

Kibbee
Kibbee

Reputation: 66112

You should be able to use the DataTable.Select() method. You can us it like this.

if(myDataTable.Select("Author = '" + AuthorName.Replace("'","''") + '").Length > 0)
    ...

The Select() funciton returns an array of DataRows for the results matching the where statement.

Upvotes: 5

Antonio Bakula
Antonio Bakula

Reputation: 20693

DataRow rw = table.AsEnumerable().FirstOrDefault(tt => tt.Field<string>("Author") == "Name");
if (rw != null)
{
// row exists
}

add to your using clause :

using System.Linq;

and add :

System.Data.DataSetExtensions

to references.

Upvotes: 11

Blast_dan
Blast_dan

Reputation: 1125

you could set the database as IEnumberable and use linq to check if the values exist. check out this link

LINQ Query on Datatable to check if record exists

the example given is 

var dataRowQuery= myDataTable.AsEnumerable().Where(row => ...

you could supplement where with any

Upvotes: 0

mservidio
mservidio

Reputation: 13057

You can use Linq. Something like:

bool exists = dt.AsEnumerable().Where(c => c.Field<string>("Author").Equals("your lookup value")).Count() > 0;

Upvotes: 17

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