Cannot convert type 'bool' to 'System.Linq.IQueryable<My.Models.MyDataList>'

public IQueryable<MyDataList> GetMyDataList(int id)
{
    var result = db.MyDataLists.All(b => b.MyDa开发者_JAVA百科taListID== id);
    return (IQueryable<MyDataList>)result ;
}

The All method returns a boolean indicating whether all of the items match a condition.

You're trying to call Where, not All.

What you want is Where() not All(). All() is like "Do all items in the list satisfy this condition or not?" not "get all items that satisfy condition".

All returns a bool indicating if all items in the list match the predicate. You're then trying to cast bool to IQueryable<MyDataList>

public IQueryable<MyDataList> GetMyDataList(int id)  
{      
     return db.MyDataLists.Where(b => b.MyDataListID== id);
} 

Thats probably what you wanna do.