Full-Text Search with Index

The index:

// The IndexEntry class defines the index-fields
class Employees_ByNotes_IndexEntry
{
    private ?string $employeeNotes = null;

    public function getEmployeeNotes(): ?string
    {
        return $this->employeeNotes;
    }

    public function setEmployeeNotes(?string $employeeNotes): void
    {
        $this->employeeNotes = $employeeNotes;
    }
}
class Employees_ByNotes extends AbstractIndexCreationTask
{
    public function __construct()
    {
        parent::__construct();

        // The 'Map' function defines the content of the index-fields
        $this->map =
            "from employee in docs.Employees " .
            "select new " .
            "{ " .
               " employee_notes = employee.Notes[0]" .
            "}";

        # Configure the index-field for FTS:
        # Set 'FieldIndexing.Search' on index-field 'employee_notes'
        $this->index("employee_notes", FieldIndexing::search());

        # Optionally: Set your choice of analyzer for the index-field:
        # Here the text from index-field 'EmployeeNotes' will be tokenized by 'WhitespaceAnalyzer'.
        $this->analyze("employee_notes", "WhitespaceAnalyzer");

        # Note:
        # If no analyzer is set then the default 'RavenStandardAnalyzer' is used.
    }
}

Query with Search:

• Use search to make a full-text search when querying the index.

• Refer to Full-Text search with dynamic queries for all available Search options,
  such as using wildcards, searching for multiple terms, etc.

/** @var array<Employee> $employees */
$employees = $session
     // Query the index
    ->query(Employees_ByNotes_IndexEntry::class, Employees_ByNotes::class)
     // Call 'Search':
     // pass the index field that was configured for FTS and the term to search for.
    ->search("EmployeeNotes", "French")
    ->ofType(Employee::class)
    ->toList();

// * Results will contain all Employee documents that have 'French' in their 'Notes' field.
//
// * Search is case-sensitive since field was indexed using the 'WhitespaceAnalyzer'
//   which preserves casing.

/** @var array<Employee> $employees */
$employees = $session->advanced()
     // Query the index
    ->documentQuery(Employees_ByNotes_IndexEntry::class, Employees_ByNotes::class)
     // Call 'Search':
     // pass the index field that was configured for FTS and the term to search for.
    ->search("EmployeeNotes", "French")
    ->ofType(Employee::class)
    ->toList();

// * Results will contain all Employee documents that have 'French' in their 'Notes' field.
//
// * Search is case-sensitive since field was indexed using the 'WhitespaceAnalyzer'
//   which preserves casing.

from index "Employees/ByNotes"
where search(EmployeeNotes, "French")

The index:

class EmployeeData
{
    private ?string $firstName = null;
    private ?string $lastName = null;
    private ?string $title = null;
    private ?string $notes = null;

    // ... getters and setters
}

class EmployeeDataArray extends TypedArray
{
    protected function __construct()
    {
        parent::__construct(EmployeeData::class);
    }
}

class Employees_ByEmployeeData_IndexEntry
{
    public ?EmployeeDataArray  $employeeData = null;
}
class Employees_ByEmployeeData extends AbstractIndexCreationTask
{
    public function __construct()
    {
        parent::__construct();

        $this->map =
            "from employee in docs.Employees " .
            "select new {" .
            "  EmployeeData = " .
            "  {" .
            # Multiple document-fields can be indexed
            # into the single index-field 'employee_data'
            "    employee.FirstName," .
            "    employee.LastName," .
            "    employee.Title," .
            "    employee.Notes" .
            "  }" .
            "}";

        // Configure the index-field for FTS:
        // Set 'FieldIndexing.Search' on index-field 'EmployeeData'
        $this->index("EmployeeData", FieldIndexing::search());

        // Note:
        // Since no analyzer is set then the default 'RavenStandardAnalyzer' is used.
    }
}

Sample query:

/** @var array<Employee> $employees */
$employees = $session
     // Query the static-index
    ->query(Employees_ByEmployeeData_IndexEntry::class, Employees_ByEmployeeData::class)
     // A logical OR is applied between the following two Search calls:
    ->search("EmployeeData", "Manager")
     // A logical AND is applied between the following two terms:
    ->search("EmployeeData", "French Spanish", SearchOperator::and())
    ->ofType(Employee::class)
    ->toList();

// * Results will contain all Employee documents that have:
//   ('Manager' in any of the 4 document-fields that were indexed)
//   OR
//   ('French' AND 'Spanish' in any of the 4 document-fields that were indexed)
//
// * Search is case-insensitive since the default analyzer is used

/** @var array<Employee> $employees */
$employees = $session->advanced()
     // Query the static-index
    ->documentQuery(Employees_ByEmployeeData_IndexEntry::class, Employees_ByEmployeeData::class)
    ->openSubclause()
     // A logical OR is applied between the following two Search calls:
    ->search("EmployeeData", "Manager")
     // A logical AND is applied between the following two terms:
    ->search("EmployeeData", "French Spanish", SearchOperator::and())
    ->closeSubclause()
    ->ofType(Employee::class)
    ->toList();

// * Results will contain all Employee documents that have:
//   ('Manager' in any of the 4 document-fields that were indexed)
//   OR
//   ('French' AND 'Spanish' in any of the 4 document-fields that were indexed)
//
// * Search is case-insensitive since the default analyzer is used

from index "Employees/ByEmployeeData"
where (search(EmployeeData, "Manager") or search(EmployeeData, "French Spanish", and))

• To search across ALL fields in a document without defining each one explicitly, use the AsJson method, which is available in the C# LINQ string that is assigned to the map property in the PHP index class, as shown in the example below.

• This approach makes the index robust to changes in the document schema.
  By calling .Select(x => x.Value) on the result of AsJson(...), the index automatically includes values from ALL existing and newly added properties and there is no need to update the index when the document structure changes.

• This indexing method is supported only when using Lucene as the indexing engine.

The index:

class Products_ByAllValues_IndexEntry
{
    public ?string $allValues = null;
    public function getAllValues(): ?string
    {
        return $this->allValues;
    }
    public function setAllValues(?string $allValues): void
    {
        $this->allValues = $allValues
    }
}

class Products_ByAllValues extends AbstractIndexCreationTask
{
    public function __construct()
    {
        parent::__construct();

        $this->map = "docs.Products.Select(product => new { " .
            # Use the 'AsJson' method to convert the document into a JSON-like structure
            # and call 'Select' to extract only the values of each property
            "    allValues = this.AsJson(product).Select(x => x.Value) " .
            "})";

        # Configure the index-field for FTS:
        # Set 'FieldIndexing::search' on index-field 'allValues'
        $this->index("allValues", FieldIndexing::search());
        
        # Set the search engine type to Lucene:
        $this->setSearchEngineType(SearchEngineType::lucene());
    }
}

Sample query:

$results = $session->query(Products_ByAllValues_IndexEntry::class, Products_ByAllValues::class)
        ->search("allValues", "tofu")
        ->ofType(Product::class)
        ->toList();
        
// * Results will contain all Product documents that have 'tofu'
//   in ANY of their fields.
//
// * Search is case-insensitive since the default analyzer is used.

from index "Products/ByAllValues"
where search(allValues, "tofu")

• To prioritize results, you can provide a boost value to the searched terms.
  This can be applied by either of the following:

  • Add a boost value to the relevant index-field inside the index definition.
    Refer to the indexes Boosting article.

  • Add a boost value to the queried terms at query time.
    Refer to the Boost search results article.