added DTOs and models

src/Main.java

@@ -1,9 +1,8 @@
-import data.enums.CustomReadPreparedStatements;
+import data.enums.CustomPreparedStatementsRead;
+import data.models.QueryResultsModel;
 import services.AppConfigService;
 import services.DatabaseService;
 
-import java.sql.ResultSet;
-
 public class Main {
     public static void main(String[] args) {
         final App app = new App();
@@ -21,7 +20,7 @@ class App {
     final AppConfigService appConfigService;
 
     public void run() {
-        //appConfigService.promptUserArguments();
+        appConfigService.promptUserArguments();
-        final ResultSet[] resultSetsQuery1 = databaseService.executeReadReportsEndpoint(CustomReadPreparedStatements.HighestAndLowest10Vaccination);
+        final QueryResultsModel resultSetsQuery1 = databaseService.executeReadReportsEndpoint(CustomPreparedStatementsRead.HighestAndLowest10Vaccination);
     }
 }

src/apis/DatabaseApi.java

@@ -5,9 +5,9 @@ import data.dtos.QueryDTO;
 import java.sql.*;
 
 public class DatabaseApi {
-    public PreparedStatement performQuery(QueryDTO queryDTO, Connection connection) {
+    public PreparedStatement performReadQuery(QueryDTO queryDTO, Connection connection) {
         try {
-            PreparedStatement statement = connection.prepareStatement(queryDTO.queryTemplate().statementData);
+            PreparedStatement statement = connection.prepareStatement(queryDTO.queryTemplate().statementTemplate);
             statement.execute();
             return statement;
         } catch (SQLException e) {

src/data/dtos/QueryDTO.java

@@ -1,7 +1,7 @@
 package data.dtos;
 
-import data.enums.CustomReadPreparedStatements;
+import data.enums.CustomPreparedStatementsRead;
 
-public record QueryDTO(CustomReadPreparedStatements queryTemplate, Object[] placeholderReplacements) {
+public record QueryDTO(CustomPreparedStatementsRead queryTemplate, Object[] placeholderReplacements) {
 
 }

src/data/enums/CustomPreparedStatementsRead.java

@@ -0,0 +1,19 @@
+package data.enums;
+
+public enum CustomPreparedStatementsRead {
+    HighestAndLowest10Vaccination("""
+            
+            """
+    ),
+
+    HighestInfectionsPer100K("""
+            
+            """
+    );
+
+    public final String statementTemplate;
+
+    private CustomPreparedStatementsRead(String statementTemplate) {
+        this.statementTemplate = statementTemplate;
+    }
+}

src/data/enums/CustomReadPreparedStatements.java

@@ -1,34 +0,0 @@
-package data.enums;
-
-public enum CustomReadPreparedStatements {
-    HighestAndLowest10Vaccination("""
-            WITH vacc_count_per_country AS (
-              SELECT iso_country, SUM(daily_vaccinations) as total_vaccinations
-              FROM vaccinations
-              GROUP BY iso_country
-            )
-            SELECT name, total_vaccinations
-            FROM countries JOIN vacc_count_per_country
-            ON countries.code = vacc_count_per_country.iso_country
-            ORDER BY total_vaccinations DESC
-            LIMIT 10;
-            
-            WITH vacc_count_per_country AS (
-              SELECT iso_country, SUM(daily_vaccinations) as total_vaccinations
-              FROM vaccinations
-              GROUP BY iso_country
-            )
-            SELECT name, total_vaccinations
-            FROM countries JOIN vacc_count_per_country
-            ON countries.code = vacc_count_per_country.iso_country
-            ORDER BY total_vaccinations ASC
-            LIMIT 10;
-            """
-    );
-
-    public final String statementData;
-
-    private CustomReadPreparedStatements(String statementData) {
-        this.statementData = statementData;
-    }
-}

src/data/models/QueryResultsModel.java

@@ -0,0 +1,11 @@
+package data.models;
+
+import java.sql.ResultSet;
+
+/**
+ * Stores the results obtained from executing an SQL query.
+ * Essentially a type-def, which is not natively supported in Java.
+ * @param resultSets Result of the query
+ */
+public record QueryResultsModel(java.util.ArrayList<ResultSet> resultSets) {
+}

src/services/DatabaseService.java

@@ -2,9 +2,9 @@ package services;
 
 import apis.DatabaseApi;
 import data.dtos.QueryDTO;
-import data.enums.CustomReadPreparedStatements;
+import data.enums.CustomPreparedStatementsRead;
+import data.models.QueryResultsModel;
 
-import javax.xml.transform.Result;
 import java.sql.*;
 import java.util.ArrayList;
 
@@ -12,9 +12,9 @@ import java.util.ArrayList;
  * Stores the active connection between the app and the local SQL Server.
  */
 public class DatabaseService {
-    private final String url = "jdbc:postgresql://localhost:5432/lunatech_covid";
+    private static  final String url = "jdbc:postgresql://localhost:5432/lunatech_covid";
-    private final String user = "postgres";
+    private static final String user = "postgres";
-    private final String password = "postgres";
+    private static final String password = "postgres";
 
     private final DatabaseApi databaseApi;
     private final Connection connection;
@@ -24,9 +24,9 @@ public class DatabaseService {
         databaseApi = new DatabaseApi();
     }
 
-    public ResultSet[] executeReadReportsEndpoint(CustomReadPreparedStatements customPreparedStatement) {
+    public QueryResultsModel executeReadReportsEndpoint(CustomPreparedStatementsRead customPreparedStatement) {
         final QueryDTO queryDTO = new QueryDTO(customPreparedStatement, new Object[]{});
-        final PreparedStatement resultStatement = databaseApi.performQuery(queryDTO, connection);
+        final PreparedStatement resultStatement = databaseApi.performReadQuery(queryDTO, connection);
         try {
             final ArrayList<ResultSet> resultSets = new ArrayList<>();
             do {
@@ -34,7 +34,7 @@ public class DatabaseService {
             }
             while (resultStatement.getMoreResults());
 
-            return resultSets.toArray(new ResultSet[0]);
+            return new QueryResultsModel(resultSets);
         } catch (SQLException e) {
             throw new RuntimeException(e);
         }