General LINQ queries

TAN WhoAMI

13y1.7kLINQ

say I have 2 columns, ColumnA and ColumnB from a table named TableAB,

with sets of data like this

ColumnA               ColumnB
======               ======
12345                   67890
54321                   67809
......                     ........
67890                   abcde
67809                   fghkm
.......                     .....

I would like to do a LINQ queries to give me results such that when the ColumnB values appear in ColumnA, then ColumnB gives the new values such that

Results
======
12345abcde
54321fghkm

Is this possible?

Appreciate if there is some code queries.

thanks.

9 Replies

Know the answer? Post it — somebody with the same question will find it here.

Jignesh Trivedi13y ago
Accepted answer
hi,
If your class A like...
class TableA
{
    public string ColumnA { get; set; }
    public string ColumnB { get; set; }
}
try following code
List tableA = new List();
tableA.Add(new TableA { ColumnA = "12345", ColumnB = "67890" });
tableA.Add(new TableA { ColumnA = "54321", ColumnB = "67809" });
tableA.Add(new TableA { ColumnA = "67890", ColumnB = "abcde" });
tableA.Add(new TableA { ColumnA = "67809", ColumnB = "fghkm" });
var test = from a in tableA
            join b in tableA on a.ColumnA equals b.ColumnB
            select b.ColumnA + a.ColumnB;
foreach (var data in test)
{
    Console.WriteLine(data);
}
hope this will help you.
0
TAN WhoAMI13y ago
got it solved already, thanks for your help.
0
Iftikar Hussain13y ago
the sql query will be

select a.ColumnA+b.ColumnB from TableAB a
inner join b on a.ColumnB=b.ColumnA

Regards,
Iftikar
0
TAN WhoAMI13y ago
can I know the equivalent of the SQL query to achieve the above?
0
Iftikar Hussain13y ago
try like this

DbCOntext db=new DbContext()
var result=from a in db.TableAB
join b in db.TableAB on a.ColumnB=b.ColumnA
select new
{
a.ColumnA+b.ColumnB
};

Regards,
Iftikar
0
TAN WhoAMI13y ago
there is only one table. Within this one table, if the value in ColumnB appears also in ColumnA, then we want to merge the value of ColumA and ColumnB such that ColumnB gets the new values, see example above.

thanks.
0
Iftikar Hussain13y ago
what condition need to bring merged result from these two table?

Regards,
Iftikar
0
TAN WhoAMI13y ago
there is only ONE table name TableAB here.
0
Iftikar Hussain13y ago
Hi,
What is the relation between these two table? Please provide more details.

Regards,
Iftikar
0