How Can I Pivot Data Using LINQ?

Pivot Data Using LINQ

In data processing, pivoting refers to transforming data from a format with multiple columns and rows to a format with multiple rows and columns. Here's how you can perform data pivoting using LINQ:

Consider a collection of items containing an TypeCode enum and a User object. As described by the inquiry, you want to flatten the collection and present it in a grid-like structure, as shown in the sample data provided:

TypeCode	User
1	Don Smith
1	Mike Jones
1	James Ray
2	Tom Rizzo
2	Alex Homes
3	Andy Bates

The desired output would be:

1	2	3
Don Smith	Tom Rizzo	Andy Bates
Mike Jones	Alex Homes
James Ray

LINQ Solution:

LINQ can efficiently handle this type of pivoting operation. Here's a code snippet that demonstrates how:

// Sample data
var data = new[] {
    new { Foo = 1, Bar = "Don Smith"},
    new { Foo = 1, Bar = "Mike Jones"},
    new { Foo = 1, Bar = "James Ray"},
    new { Foo = 2, Bar = "Tom Rizzo"},
    new { Foo = 2, Bar = "Alex Homes"},
    new { Foo = 3, Bar = "Andy Bates"},
};

// Group into columns and select rows per column
var grps = from d in data
          group d by d.Foo
          into grp
          select new {
              Foo = grp.Key,
              Bars = grp.Select(d2 => d2.Bar).ToArray()
          };

// Find the total number of (data) rows
int rows = grps.Max(grp => grp.Bars.Length);

// Output columns
foreach (var grp in grps) {
    Console.Write(grp.Foo + "\t");
}
Console.WriteLine();

// Output data
for (int i = 0; i < rows; i++) {
    foreach (var grp in grps) {
        Console.Write((i < grp.Bars.Length ? grp.Bars[i] : null) + "\t");
    }
    Console.WriteLine();
}

Output:

1 2 3
Don Smith Tom Rizzo Andy Bates
Mike Jones Alex Homes
James Ray

This LINQ solution effectively pivots the data into the desired format by grouping items with the same Foo value and then selecting the Bars (user names) per column. It calculates the maximum number of rows based on the entries in each column and generates the output in a well-structured table form.

The above is the detailed content of How Can I Pivot Data Using LINQ?. For more information, please follow other related articles on the PHP Chinese website!