ORM/Panache: rely on ORM getResultCount

This allows us to not care about which parameters are set on the count
query, since `order by` parameters are ignored by ORM. Which is not
the case if we write our own count query.

Note that this is not yet available in HR, so we have to keep the count
query logic around until that's available.

Fixes #40962

extensions/panache/hibernate-orm-panache-common/runtime/src/main/java/io/quarkus/hibernate/orm/panache/common/runtime/CommonPanacheQueryImpl.java

@@ -46,7 +46,12 @@ public void close() {
      * this is the original Panache-Query, if any (can be null)
      */
     private String originalQuery;
-    protected String countQuery;
+    /**
+     * This is only used by the Spring Data JPA extension, due to Spring's Query annotation allowing a custom count query
+     * See https://docs.spring.io/spring-data/jpa/reference/jpa/query-methods.html#jpa.query-methods.at-query.native
+     * Otherwise we do not use this, and rely on ORM to generate count queries
+     */
+    protected String customCountQueryForSpring;
     private String orderBy;
     private EntityManager em;
 
@@ -72,7 +77,7 @@ public CommonPanacheQueryImpl(EntityManager em, String query, String originalQue
     private CommonPanacheQueryImpl(CommonPanacheQueryImpl<?> previousQuery, String newQueryString, String countQuery) {
         this.em = previousQuery.em;
         this.query = newQueryString;
-        this.countQuery = countQuery;
+        this.customCountQueryForSpring = countQuery;
         this.orderBy = previousQuery.orderBy;
         this.paramsArrayOrMap = previousQuery.paramsArrayOrMap;
         this.page = previousQuery.page;
@@ -118,13 +123,14 @@ public <T> CommonPanacheQueryImpl<T> project(Class<T> type) {
             }
 
             newQuery.append("new ").append(type.getName()).append("(").append(selectClause).append(")").append(from);
-            return new CommonPanacheQueryImpl<>(this, newQuery.toString(), "select count(*) " + from);
+            // I think projections do not change the result count, so we can keep the custom count query
+            return new CommonPanacheQueryImpl<>(this, newQuery.toString(), customCountQueryForSpring);
         }
 
         // build select clause with a constructor expression
         String selectClause = "SELECT " + getParametersFromClass(type, null);
-        return new CommonPanacheQueryImpl<>(this, selectClause + selectQuery,
-                "select count(*) " + selectQuery);
+        // I think projections do not change the result count, so we can keep the custom count query
+        return new CommonPanacheQueryImpl<>(this, selectClause + selectQuery, customCountQueryForSpring);
     }
 
     private StringBuilder getParametersFromClass(Class<?> type, String parentParameter) {
@@ -276,35 +282,28 @@ public void withHint(String hintName, Object value) {
 
     // Results
 
-    @SuppressWarnings("unchecked")
     public long count() {
         if (count == null) {
-            String selectQuery = query;
-            if (PanacheJpaUtil.isNamedQuery(query)) {
-                org.hibernate.query.Query q = (org.hibernate.query.Query) em.createNamedQuery(query.substring(1));
-                selectQuery = q.getQueryString();
-            }
-
-            Query countQuery = em.createQuery(countQuery(selectQuery));
-            if (paramsArrayOrMap instanceof Map)
-                AbstractJpaOperations.bindParameters(countQuery, (Map<String, Object>) paramsArrayOrMap);
-            else
-                AbstractJpaOperations.bindParameters(countQuery, (Object[]) paramsArrayOrMap);
-            try (NonThrowingCloseable c = applyFilters()) {
-                count = (Long) countQuery.getSingleResult();
+            if (customCountQueryForSpring != null) {
+                Query countQuery = em.createQuery(customCountQueryForSpring);
+                if (paramsArrayOrMap instanceof Map)
+                    AbstractJpaOperations.bindParameters(countQuery, (Map<String, Object>) paramsArrayOrMap);
+                else
+                    AbstractJpaOperations.bindParameters(countQuery, (Object[]) paramsArrayOrMap);
+                try (NonThrowingCloseable c = applyFilters()) {
+                    count = (Long) countQuery.getSingleResult();
+                }
+            } else {
+                @SuppressWarnings("rawtypes")
+                org.hibernate.query.Query query = (org.hibernate.query.Query) createBaseQuery();
+                try (NonThrowingCloseable c = applyFilters()) {
+                    count = query.getResultCount();
+                }
             }
         }
         return count;
     }
 
-    private String countQuery(String selectQuery) {
-        if (countQuery != null) {
-            return countQuery;
-        }
-
-        return PanacheJpaUtil.getFastCountQuery(selectQuery);
-    }
-
     @SuppressWarnings("unchecked")
     public <T extends Entity> List<T> list() {
         Query jpaQuery = createQuery();

extensions/panache/hibernate-orm-panache/runtime/src/main/java/io/quarkus/hibernate/orm/panache/runtime/CustomCountPanacheQuery.java

@@ -15,7 +15,7 @@ public CustomCountPanacheQuery(EntityManager em, Query jpaQuery, String customCo
             Object paramsArrayOrMap) {
         super(new CommonPanacheQueryImpl<>(em, castQuery(jpaQuery).getQueryString(), null, null, paramsArrayOrMap) {
             {
-                this.countQuery = customCountQuery;
+                this.customCountQueryForSpring = customCountQuery;
             }
         });
     }

extensions/panache/panache-hibernate-common/runtime/src/main/java/io/quarkus/panache/hibernate/common/runtime/PanacheJpaUtil.java

@@ -38,6 +38,8 @@ public class PanacheJpaUtil {
     /**
      * This turns an HQL (already expanded from Panache-QL) query into a count query, using text manipulation
      * if we can, because it's faster, or fall back to using the ORM HQL parser in {@link #getCountQueryUsingParser(String)}
+     *
+     * @deprecated we should use SelectionQuery.getResultCount() when supported by HR (ORM already supports it)
      */
     public static String getFastCountQuery(String query) {
         // try to generate a good count query from the existing query
@@ -85,6 +87,8 @@ public static String getFastCountQuery(String query) {
     /**
      * This turns an HQL (already expanded from Panache-QL) query into a count query, using the
      * ORM HQL parser. Slow version, see {@link #getFastCountQuery(String)} for the fast version.
+     *
+     * @deprecated we should use SelectionQuery.getResultCount() when supported by HR (ORM already supports it)
      */
     public static String getCountQueryUsingParser(String query) {
         HqlLexer lexer = new HqlLexer(CharStreams.fromString(query));

integration-tests/hibernate-orm-panache/src/main/java/io/quarkus/it/panache/Bug40962Entity.java

@@ -0,0 +1,11 @@
+package io.quarkus.it.panache;
+
+import jakarta.persistence.Entity;
+
+import io.quarkus.hibernate.orm.panache.PanacheEntity;
+
+@Entity
+public class Bug40962Entity extends PanacheEntity {
+    public String name;
+    public String location;
+}

integration-tests/hibernate-orm-panache/src/main/java/io/quarkus/it/panache/TestEndpoint.java

@@ -11,6 +11,7 @@
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -1843,4 +1844,16 @@ public String testBug36496() {
                 Person.count("WITH id AS (SELECT p.id AS pid FROM Person2 AS p) SELECT count(*) FROM Person2 p"));
         return "OK";
     }
+
+    @GET
+    @Path("40962")
+    @Transactional
+    public String testBug40962() {
+        // should not throw
+        //        Bug40962Entity.find("name = :name ORDER BY locate(location, :location) DESC",
+        //                Map.of("name", "Demo", "location", "something")).count();
+        Bug40962Entity.find("FROM Bug40962Entity WHERE name = :name ORDER BY locate(location, :location) DESC",
+                Map.of("name", "Demo", "location", "something")).count();
+        return "OK";
+    }
 }

integration-tests/hibernate-orm-panache/src/test/java/io/quarkus/it/panache/PanacheFunctionalityTest.java

@@ -254,4 +254,9 @@ public void testBug26308() {
     public void testBug36496() {
         RestAssured.when().get("/test/36496").then().body(is("OK"));
     }
+
+    @Test
+    public void testBug40962() {
+        RestAssured.when().get("/test/40962").then().body(is("OK"));
+    }
 }