Creating new array inside expression string - Execute extension method

[Mat3oo]

With this expressions string passed into Execute extension method:

Where(p => new []{ 1, 2, 3, 4 }.Contains(p.Id))

library loses the new keyword and replace it with (IEnumerable<int>) cast, so causing exception.

Example repo (newArray branch) replicating the problem.

Exception details:

• Message:

  The LINQ expression 'DbSet<Element>
  .Where(e => e.Name == "test")
  .Where(e => e.Active)
  .Where(e => (IEnumerable<int>)int[] { 1, 2, 3, 4, }
      .Contains(e.Id))' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to either AsEnumerable(), AsAsyncEnumerable(), ToList(), or ToListAsync(). See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.

• Stack trace:

  at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.<VisitMethodCall>g__CheckTranslated|8_0(ShapedQueryExpression translated, <>c__DisplayClass8_0& )
  at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
  at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
  at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
  at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
  at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
  at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
  at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
  at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
  at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
  at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
  at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
  at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
  at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
  at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)
  at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)
  at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass9_0`1.<Execute>b__0()
  at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func`1 compiler)
  at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
  at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
  at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)
  at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetEnumerator()
  at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
  at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
  at Z.Expressions.EvalLinq.Execute(String code, Boolean isQueryable, Expression exp, Object[] parameters)
  at System.Linq.QueryableDynamic.Execute[TValue](IQueryable source, String expression, Object parameter)
  at System.Linq.QueryableDynamic.Execute[TValue](IQueryable source, String expression)
  at EntityFramework_Classic_Count_example.Program.Main(String[] args) in *Removed by me*\EntityFramework-Classic_Count_example\EntityFramework-Classic_Count_example\Program.cs:line 21

[JonathanMagnan]

Hello @Mat3oo ,

Is there a reason why you don't create the list outside of the LINQ query and check in the LINQ if the list contains it?

Such as:

var list = new List<int> { 1, 2, 3, 4};

DbSet<Element>
    .Where(e => e.Name == "test")
    .Where(e => e.Active)
    .Where(e => list.Contains(e.Id));

Best Regards,

Jon

[Mat3oo]

I'm using urs Execute method:

var list = new List<int> { 1, 2, 3, 4};

DbSet<Element>
    .Execute<object>(
    "Where(e => e.Name == \"test\")" +
    "Where(e => e.Active)" +
    "Where(e => list.Contains(e.Id))");

and in this case it's not possible for string to know about list. In the repo from first comment is nice example.

*Missclick Close issue

[JonathanMagnan]

You can pass it in parameter such as:

var list = new List<int> { 1, 2, 3, 4};

DbSet<Element>
    .Execute<object>(
    "Where(e => e.Name == \"test\")" +
    "Where(e => e.Active)" +
    "Where(e => list.Contains(e.Id))", new { list });

[Mat3oo]

You can pass it in parameter

I know, but not the case for me. I passing string between services, so I would like to use new [] {} inplace.

[JonathanMagnan]

Hello @Mat3oo ,

Just to let you know that we continue to work on both issues.

We made some progression last week and find out why this happening (due to a convert on our side for using the Contains method).

Everything work without EF since this CAST doesn't cause any problem. However, in EF, this additional CAST cannot be translated in SQL which throw the error.

[JonathanMagnan]

Hello @Mat3oo ,

A new version has been released today.

We fixed this issue and the C# Eval Library will no longer try to CAST the array into IEnumerable which was causing the error in Entity Framework.

Let me know if everything works as expected.

Best Regards,

Jon

[Mat3oo]

It's seems with Z.Expressions.Eval v4.0.18 the problem new [] is resolved, and also #59 working now as expected, gj 👍🏼.

[JonathanMagnan]

Great Mat3oo!

Don't hesitate to contact me for further assistance.

Best regards,

Jon