server/springboot: alter "list tickets" SQL query on the fly

server/springboot/src/main/java/com/styra/tickethub_springboot/dao/model/TicketRepository.java

@@ -1,12 +1,42 @@
 package com.styra.tickethub_springboot.dao.model;
 
+import com.styra.tickethub_springboot.App;
+import java.util.List;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.data.domain.Sort;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.jpa.repository.QueryRewriter;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
-import java.util.List;
-
 @Repository
-public interface TicketRepository extends JpaRepository<Ticket, Integer> {
-    List<Ticket> findByTenant(Tenant tenant);
+public interface TicketRepository
+    extends JpaRepository<Ticket, Integer>, QueryRewriter {
+    @Query(
+        value = "SELECT t.id, t.customer, t.description, t.last_updated, t.resolved, t.tenant FROM \"Tickets\" t LEFT JOIN \"Tenants\" t1 ON t1.id=t.tenant WHERE t1.name=:#{#tenant.name}",
+        nativeQuery = true,
+        queryRewriter = TicketRepository.class
+    )
+    List<Ticket> findByTenant(@Param("tenant") Tenant tenant);
+
     List<Ticket> findByTenantAndId(Tenant tenant, Integer id);
+
+    @Override
+    default String rewrite(String query, Sort sort) {
+        // Omitted:
+        // 1. get conditions from OPA, after feeding it query and user information
+        // 2. convert conditions to SQL WHERE clause
+        //
+        // SQL logging uncovered **a lot** of queries happening for "list tickets".
+        // I'd assume that they're done automatically by Spring Data JPA, to ensure
+        // relationships etc; but it also means they are under the radar of this rewriter.
+        // However, I'd envision that there's one rewriter that would be used with all
+        // the repositories, so maybe we would end up covering call queries after all.
+        String rewritten = query + " AND t.resolved = false"; // leading space is crucial
+        Logger logger = LoggerFactory.getLogger(App.class);
+        logger.info("rewritten: " + rewritten);
+        return rewritten;
+    }
 }

server/springboot/src/main/resources/application.properties

@@ -37,3 +37,9 @@ logging.level.com.styra.tickethub_springboot.dao.model=TRACE
 # production, you probably shouldn't do this.
 spring.security.user.name=demouser
 spring.security.user.password=letmein
+
+# dump all the SQL
+spring.jpa.show-sql=true
+spring.jpa.properties.hibernate.format_sql=true
+logging.level.org.hibernate.SQL=DEBUG
+logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE