public SearchResults <Book> SearchBooks([FromUrl] BookSearch searchParams)
{
searchParams = searchParams.DefaultIfNull(defaultOrderBy: "title"); //creates empty object if null and sets Take = 10 and default sort
var session = OpenSession();
return(session.SearchBooks(searchParams));
}
public SearchResults <Book> SearchBooks([FromQuery] BookSearch searchParams)
{
searchParams = searchParams.DefaultIfNull(defaultOrderBy: "title"); //creates empty object if null and sets Take = 10 and default sort
var session = OpenSession();
// Original method returns results with IBook entities
var tempResults = session.SearchBooks(searchParams);
// convert to Book dto objects
var results = new SearchResults <Book>()
{
TotalCount = tempResults.TotalCount,
Results = tempResults.Results.Select(b => b.ToModel()).ToList()
};
return(results);
}
public void TestLinqSearch()
{
var app = SetupHelper.BooksApp;
var session = app.OpenSession();
//We use catalog controller's SearchBooks method to invoke search method.
// This is also a demo of using Api controllers outside Web server environment
var contr = new CatalogController(app.CreateSystemContext());
//User search helper method with all possible search terms. Let's find c# book
var searchParams = new BookSearch() {
Title = "C#", Categories = "Programming,Fiction", MaxPrice = 100.0, Publisher = "MS",
PublishedAfter = new DateTime(2000, 1, 1), PublishedBefore = DateTime.Now,
AuthorLastName = "Sharp", OrderBy = "Price-desc,pubname,PublishedOn-desc",
Skip = 0, Take = 5
};
var bookResults = contr.SearchBooks(searchParams);
//PrintLastSql(session);
Assert.AreEqual(1, bookResults.Results.Count, "Failed to find c# book");
/* Here's the resulting SQL for MS SQL 2012:
SELECT f$.[Id], f$.[Title], f$.[Description], f$.[PublishedOn], f$.[Abstract], f$.[Category], f$.[Editions], f$.[Price],
f$.[CreatedIn], f$.[UpdatedIn], f$.[Publisher_Id]
FROM [books].[Book] f$, [books].[Publisher] t1$
WHERE (t1$.[Id] = f$.[Publisher_Id]) AND ((f$.[Title] LIKE @P5 ESCAPE '\') AND
(f$.[Price] <= @P0) AND (t1$.[Name] LIKE @P6 ESCAPE '\') AND
(f$.[PublishedOn] >= @P1) AND
(f$.[PublishedOn] <= @P2) AND
f$.[Category] IN (0, 1) AND
(f$.[Id] IN (SELECT ba$.[Book_Id]
FROM [books].[BookAuthor] ba$, [books].[Author] t2$
WHERE (t2$.[Id] = ba$.[Author_Id]) AND (t2$.[LastName] LIKE @P7 ESCAPE '\'))))
ORDER BY f$.[Price] DESC, t1$.[Name], f$.[PublishedOn] DESC
OFFSET @P3 ROWS FETCH NEXT @P4 ROWS ONLY
-- Parameters: @P0=100, @P1=[2000-01-01T00:00:00], @P2=[2015-02-28T02:05:42], @P3=0, @P4=5, @P5='c#%', @P6='MS%', @P7='Sharp%'
*/
// run with empty terms, 'get-any-top-10'
searchParams = new BookSearch() {Take = 10};
bookResults = contr.SearchBooks(searchParams);
Assert.IsTrue(bookResults.Results.Count > 3, "Must return all books");
}
public SearchResults <Book> SearchBooks([FromUrl] BookSearch searchParams)
{
searchParams = searchParams.DefaultIfNull(defaultOrderBy: "title"); //creates empty object if null and sets Take = 10 and default sort
var session = OpenSession();
// Warning about substring match (LIKE): Be careful using it in real apps, against big tables
// Match by fragment results in LIKE operator which NEVER works on real volumes.
// For MS SQL, it is OK to do LIKE with pattern that does not start with % (so it is StartsWith(smth) operator).
// AND column must be indexed - so server will use index. For match inside the string, LIKE is useless on big tables.
// In our case, Title is indexed and we use StartsWith, so it's OK
// An interesting article about speeding up string-match search in MS SQL:
// http://aboutsqlserver.com/2015/01/20/optimizing-substring-search-performance-in-sql-server/
var categories = ConvertHelper.ParseEnumArray <BookCategory>(searchParams.Categories);
var where = session.NewPredicate <IBook>()
.AndIfNotEmpty(searchParams.Title, b => b.Title.StartsWith(searchParams.Title))
.AndIfNotEmpty(searchParams.MaxPrice, b => b.Price <= (Decimal)searchParams.MaxPrice.Value)
.AndIfNotEmpty(searchParams.Publisher, b => b.Publisher.Name.StartsWith(searchParams.Publisher))
.AndIfNotEmpty(searchParams.PublishedAfter, b => b.PublishedOn.Value >= searchParams.PublishedAfter.Value)
.AndIfNotEmpty(searchParams.PublishedBefore, b => b.PublishedOn.Value <= searchParams.PublishedBefore.Value)
.AndIf(categories != null && categories.Length > 0, b => categories.Contains(b.Category));
// A bit more complex clause for Author - it is many2many, results in subquery
if (!string.IsNullOrEmpty(searchParams.AuthorLastName))
{
var qAuthBookIds = session.EntitySet <IBookAuthor>()
.Where(ba => ba.Author.LastName.StartsWith(searchParams.AuthorLastName))
.Select(ba => ba.Book.Id);
where = where.And(b => qAuthBookIds.Contains(b.Id));
}
// Alternative method for author name - results in inefficient query (with subquery for every row)
// if(!string.IsNullOrEmpty(authorLastName))
// where = where.And(b => b.Authors.Any(a => a.LastName == authorLastName));
//Use VITA-defined helper method ExecuteSearch - to build query from where predicate, get total count,
// add clauses for OrderBy, Take, Skip, run query and convert to list of model objects with TotalCount
var results = session.ExecuteSearch(where, searchParams, ibook => ibook.ToModel(), b => b.Publisher, _orderByMapping);
return(results);
}
