Solr query not returning search results

Question

I can see all the records in the Solr portal when I run the query. Here is the data of one product.
https://localhost:8983/solr/stratum_products_master_index/select?q=_templatename%3A%22product%20details%20page%22

{
        "category_t_en":"Lipstick",
        "_indexname":"stratum_products_master_index",        
        "is_active_b":true,        
        "category_t":"Lipstick",        
        "title_t_en":"Claire",
        "producttags_sm":["Cosmetics"],        
        "price_t_en":"15",        
        "productimageurl_s":"/-/media/Stratum/Project/Demo/assets/img/products/product-3.jpg",      
         "_templatename":"Product Details Page",        
        "tags_sm":["8f44b11cd2fd4d10b43ed16b847b4f9b"],        
        "price_t":"15",        
        "title_t":"Claire",       
        "_name":"claire",
        "_database":"master",
        
},

But the code doesn't return any results. I doubt if the reason is the predicate, but I'm unable to figure out what.

ProductsController.cs

BaseSearchResult<ProductSearchResultItem> result = productSearcher.GetSearchResult("stratum_products_master_index", "", "", 1, 5);

ProductSearchResultItem.cs

public class ProductSearchResultItem : SearchResultItem
    {
        [IndexField("is_active")]
        public bool IsActive { get; set; }

        [IndexField("title")]
        public string Title { get; set; }

        [IndexField("category")]
        public string Category { get; set; }

        [IndexField("tags")]
        public IEnumerable<Guid> Tags { get; set; }

        [IndexField("productimageurl")]
        public string ProductImageUrl { get; set; }

        [IndexField("producttags")]
        public List<string> ProductTags { get; set; }

        [IndexField("productpricedisplay")]
        public string ProductPriceDisplay { get; set; }
    }

patch.config

<?xml version="1.0" encoding="utf-8"?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:role="http://www.sitecore.net/xmlconfig/role/" xmlns:search="http://www.sitecore.net/xmlconfig/search/">
  <sitecore role:require="Standalone or ContentDelivery or ContentManagement" search:require="solr">
    <contentSearch>
      <indexConfigurations>
        <defaultSolrIndexConfiguration>              
          <documentOptions>
            <fields hint="raw:AddComputedIndexField">
              <field fieldName="ProductImageUrl" returnType="string">Stratum.Feature.PageContent.ComputedIndexFields.ProductImageUrl, Stratum.Feature.PageContent</field>
              <field fieldName="ProductTags" returnType="stringCollection">Stratum.Feature.PageContent.ComputedIndexFields.ProductTags, Stratum.Feature.PageContent</field>
              <field fieldName="ProductPriceDisplay" returnType="string">Stratum.Feature.PageContent.ComputedIndexFields.ProductPriceDisplay, Stratum.Feature.PageContent</field>
            </fields>
          </documentOptions>
        </defaultSolrIndexConfiguration>
      </indexConfigurations>
      <configuration type="Sitecore.ContentSearch.ContentSearchConfiguration, Sitecore.ContentSearch">
        <indexes hint="list:AddIndex">
          <index id="stratum_products_master_index" type="Sitecore.ContentSearch.SolrProvider.SolrSearchIndex, Sitecore.ContentSearch.SolrProvider">
            <param desc="name">$(id)</param>
            <param desc="core">stratum_products_master_index</param>
            <param desc="propertyStore" ref="contentSearch/indexConfigurations/databasePropertyStore" param1="$(id)" />
            <configuration ref="contentSearch/indexConfigurations/defaultSolrIndexConfiguration" />
            <strategies hint="list:AddStrategy">
              <strategy ref="contentSearch/indexConfigurations/indexUpdateStrategies/manual" role:require="(ContentManagement and !Indexing) or (ContentDelivery and !Indexing)" />
              <strategy ref="contentSearch/indexConfigurations/indexUpdateStrategies/onPublishEndAsyncSingleInstance" role:require="Standalone or (ContentManagement and Indexing) or (ContentDelivery and Indexing)" />
            </strategies>
            <locations hint="list:AddCrawler">
              <crawler type="Sitecore.ContentSearch.SitecoreItemCrawler, Sitecore.ContentSearch">
                <Database>master</Database>
                <Root>/sitecore/content/Tenant/Stratum/Home/products</Root>
              </crawler>
            </locations>
            <enableItemLanguageFallback>false</enableItemLanguageFallback>
            <enableFieldLanguageFallback>false</enableFieldLanguageFallback>
          </index>
        </indexes>
      </configuration>
    </contentSearch>
  </sitecore>
</configuration>

ProductSearcher.cs

public class ProductSearcher
    {
        private SearchService searchService = new SearchService();

        public BaseSearchResult<ProductSearchResultItem> GetSearchResult(string searchIndexName, string searchTerm, string tagId, int pageNumber, int pageSize)
        {
            var query = GetSearchQuery(searchTerm, tagId, pageNumber, pageSize);
            BaseSearchResult<ProductSearchResultItem> result = searchService.GetSearchResults<ProductSearchResultItem>(searchIndexName, query);
            return result;
        }

        private IQueryable<ProductSearchResultItem> GetSearchQuery(string searchTerm, string tagId, int pageNumber, int pageSize)
        {
            var predicate = GetSearchPredicate(searchTerm, tagId);
            IQueryable<ProductSearchResultItem> query = searchService.GetSearchQuery<ProductSearchResultItem>(Constants.SearchIndexes.Products, predicate);

            /// Apply pagination 
            query = query.Page(pageNumber, pageSize);
            return query;
        }

        private Expression<Func<ProductSearchResultItem, bool>> GetSearchPredicate(string searchTerm, string tagId)
        {
            Item productDetailsTemplateItem = SitecoreUtility.GetItem(Templates.ProductDetailsPage.ID);
            string productDetailsTemplateName = productDetailsTemplateItem != null ? productDetailsTemplateItem.Name : string.Empty;

            /// Initialize queries with True for AND queries and False for OR queries
            var andPredicate = PredicateBuilder.True<ProductSearchResultItem>();
            var orPredicate = PredicateBuilder.False<ProductSearchResultItem>();

            if (!string.IsNullOrWhiteSpace(productDetailsTemplateName))
            {
                /// get only product pages
                andPredicate = andPredicate.And(x =>  x.TemplateName.Equals(productDetailsTemplateName, StringComparison.InvariantCultureIgnoreCase));

                int test = 1;

                /// get only active products
                if (test == 1)
                {
                    andPredicate = andPredicate.And(x => x.IsActive); 
                }

                ///filter by searchTerm
                if (test == 1)
                {
                    if (!string.IsNullOrWhiteSpace(searchTerm))
                    {
                        andPredicate = andPredicate.And(x => x.Title.Like(searchTerm, 0.75f));
                    } 
                }

                ///filter by tag
                if (test == 1)
                {
                    if (!string.IsNullOrWhiteSpace(tagId))
                    {
                        andPredicate = andPredicate.And(x => x.Tags.Contains(new Guid(tagId)));
                    } 
                }
            }            

            /// append the naming predicate to the overall filter predicate
            var finalPredicate = andPredicate.And(orPredicate);

            return finalPredicate;
        }        
    }

SearchService.cs

public class SearchService
    {
        public IQueryable<T> GetSearchQuery<T>(string searchIndexName, Expression<Func<T, bool>> predicate) where T : SearchResultItem
        {
            IQueryable<T> query;

            using (var context = ContentSearchManager.GetIndex(searchIndexName).CreateSearchContext())
            {
                query = context.GetQueryable<T>().Filter(predicate);
            }

            return query;
        }

        public BaseSearchResult<T> GetSearchResults<T>(string searchIndexName, IQueryable<T> query) where T : SearchResultItem
        {
            int totalResults = 0;
            List<T> resultsByFilters = null;

            /// get the index
            ISearchIndex searchIndex = ContentSearchManager.GetIndex(searchIndexName);

            /// create a search context
            using (IProviderSearchContext context = searchIndex.CreateSearchContext())
            {
                /// get results from this index based on query
                SearchResults<T> searchResults = query.GetResults();

                if (searchResults != null)
                {
                    totalResults = searchResults.TotalSearchResults;
                    resultsByFilters = searchResults.Hits.Select(x => x.Document)?.ToList();
                }

                return new BaseSearchResult<T>
                {
                    TotalResults = totalResults,
                    ResultsByFilters = resultsByFilters
                };
            }
        }
    }

Update

This is the query logged in Search.log

24840 18:11:08 INFO  Solr Query - ?q=*:* AND _val_:__boost&start=3&rows=3&fl=*,score&fq=-*:*&fq=_indexname:(stratum_products_master_index)&wt=xml

Answer 1

The problem is with your GetSearchPredicate method.

First you create orPredicate which is always false

var orPredicate = PredicateBuilder.False<ProductSearchResultItem>();

Then you use never add any Or conditions to it and instead you use it in finalPredicate:

var finalPredicate = andPredicate.And(orPredicate);

Remove that orPredicate or use it like:

var colorExpression = PredicateBuilder.False<ProductSearchResultItem>();
colorExpression = colorExpression.Or(o => o.Color == "black");
colorExpression = colorExpression.Or(o => o.Color == "white");
andExpression = andExpression.And(colorExpression);