Simplify calls to date nested in strftime

[roji]

For example, strftime('%Y', date($date, '2 years')) can be simplifed to strftime('%Y', $date, '2 years').

(originally #24989 (comment))

[bricelam]

Note to implementor: This requires updating the logic inside SqliteExpression.Strftime to handle date in addition to strftime:

efcore/src/EFCore.Sqlite.Core/Query/Internal/SqliteExpression.cs

Lines 44 to 55 in e7c0b9d

	&& rtrimFunction2.Arguments[0] is SqlFunctionExpression strftimeFunction
	&& strftimeFunction.Name == "strftime"
	&& strftimeFunction.Arguments!.Count > 1)
	{
	// Use its timestring parameter directly in place of ours
	timestring = strftimeFunction.Arguments[1];
	// Prepend its modifier arguments (if any) to the current call
	modifiers = strftimeFunction.Arguments.Skip(2).Concat(modifiers);
	}
	var finalArguments = new[] { sqlExpressionFactory.Constant(format), timestring }.Concat(modifiers);

We should also think about whether it's possible to get nested date functions.

[jhowlett-scottlogic]

Is anyone working on this?

[bricelam]

@jhowlett-scottlogic Nope, feel free.

[jhowlett-scottlogic]

Sorry @bricelam but i have looked into this task more deeply and have found it to be above my experience level with efcore. Because of this i don't feel like i should take on this issue as i do not fully understand the repository and may not take everything required into account when designing a solution.

I hope you find someone to take on this task soon!

[bricelam]

@jhowlett-scottlogic No worries. But also feel free to ask us questions; we're always eager to help contributors get started. We have a few docs like How to contribute and Getting and Building the Code, but I'm sure we could use more.