Custom Join Operations
Learn about join operations that are possible without the use of the join clause, Join, or GroupJoin methods.
We'll cover the following...
Custom join operations
In this lesson, we’ll demonstrate the join operations that are not possible with the join clause (query syntax), or the Join and GroupJoin methods (query method).
Cross join
A cross join is the cartesian product, or combination of two or more source sequences, without any condition between the sources. In the illustration below, we combine the first sequence consisting of letters “A” and “B” with the second sequence of numbers “1,” “2,” and “3.” The output is a cartesian product.
With query syntax, we implement a cross join using multiple from clauses to introduce each data sequence independently. Below is a project illustrating a cross join between albums and publishers.
{
"version": "0.2.0",
"configurations": [
{
// Use IntelliSense to find out which attributes exist for C# debugging
// Use hover for the description of the existing attributes
// For further information visit https://github.com/OmniSharp/omnisharp-vscode/blob/master/debugger-launchjson.md
"name": ".NET Core Launch (console)",
"type": "coreclr",
"request": "launch",
"preLaunchTask": "build",
// If you have changed target frameworks, make sure to update the program path.
"program": "${workspaceFolder}/bin/Debug/net6.0/QueryData.dll",
"args": [],
"cwd": "${workspaceFolder}",
// For more information about the 'console' field, see https://aka.ms/VSCode-CS-LaunchJson-Console
"console": "internalConsole",
"stopAtEntry": false
},
{
"name": ".NET Core Attach",
"type": "coreclr",
"request": "attach"
}
]
}Click the “Run” button in the project above, then execute the command below in the terminal: ...