[persistence][database][query builder] extract into repository

persistence/database/query-builder/jooq/app/build.gradle

@@ -3,6 +3,7 @@
 plugins {
 //    id 'nu.studer.jooq' version '5.2.1'
     id 'java'
+    id 'application'
 }
 
 repositories {
@@ -28,10 +29,9 @@ dependencies {
     implementation group: 'org.jooq', name: 'jooq-codegen', version: '3.14.11'
 }
 
-//application {
-//    // Define the main class for the application.
-//    mainClass = 'hello.jooq.App'
-//}
+application {
+    mainClass = 'hello.jooq.Main'
+}
 
 tasks.named('test') {
     // Use junit platform for unit tests.

persistence/database/query-builder/jooq/app/src/main/java/hello/jooq/BookRepository.java

@@ -0,0 +1,65 @@
+package hello.jooq;
+
+import org.jooq.DSLContext;
+import org.jooq.Query;
+import org.jooq.Record;
+import org.jooq.Result;
+import org.jooq.SQLDialect;
+import org.jooq.impl.DSL;
+
+import java.sql.*;
+import java.util.List;
+
+import static org.jooq.impl.DSL.field;
+import static org.jooq.impl.DSL.table;
+
+public class BookRepository {
+
+    static String userName = "user";
+    static String password = "password";
+    static String url = "jdbc:postgresql://localhost/database";
+
+//    https://www.jooq.org/doc/3.15/manual/getting-started/use-cases/jooq-as-a-sql-builder-without-codegeneration/
+    public ResultSet getBooksPublishedIn(int year) {
+
+        ResultSet resultSet = null;
+        // Connection is the only JDBC resource that we need
+        // PreparedStatement and ResultSet are handled by jOOQ, internally
+        try (Connection conn = DriverManager.getConnection(url, userName, password)) {
+            DSLContext create = DSL.using(conn, SQLDialect.POSTGRES);
+            Query query = create.select(field("book.title"), field("author.first_name"), field("author.last_name"))
+                    .from(table("book"))
+                    .join(table("author"))
+                    .on(field("book.author_id").eq(field("author.id")))
+                    .where(field("book.published_in").eq(year));
+            String sql = query.getSQL();
+            List<Object> bindValues = query.getBindValues();
+
+            PreparedStatement pstmt = conn.prepareStatement(sql);
+            pstmt.setInt(1, (Integer) bindValues.get(0));
+            resultSet = pstmt.executeQuery();
+        }
+
+        // For the sake of this tutorial, let's keep exception handling simple
+        catch (Exception e) {
+            e.printStackTrace();
+        }
+        return resultSet;
+    }
+
+    public Result<Record> getAuthors() {
+
+        Result<Record> result = null;
+
+        try (Connection conn = DriverManager.getConnection(url, userName, password)) {
+            DSLContext create = DSL.using(conn, SQLDialect.POSTGRES);
+            result = create.select().from(table("author")).fetch();
+        }
+        catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        return result;
+
+    }
+}

persistence/database/query-builder/jooq/app/src/main/java/hello/jooq/Main.java

@@ -0,0 +1,26 @@
+package hello.jooq;
+
+import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+
+public class Main {
+
+    public static void main(String[] args) throws SQLException {
+        System.getProperties().setProperty("org.jooq.no-logo", "true");
+        BookRepository bookRepository = new BookRepository();
+        ResultSet resultSet = bookRepository.getBooksPublishedIn(1948);
+
+        ResultSetMetaData rsmd = resultSet.getMetaData();
+        int columnsNumber = rsmd.getColumnCount();
+        while (resultSet.next()) {
+            for (int i = 1; i <= columnsNumber; i++) {
+                if (i > 1) System.out.print(",  ");
+                String columnValue = resultSet.getString(i);
+                System.out.print(rsmd.getColumnName(i) + ": " + columnValue);
+            }
+            System.out.println("");
+        }
+
+    }
+}

persistence/database/query-builder/jooq/app/src/test/java/hello/jooq/BookRepositoryTest.java

@@ -0,0 +1,26 @@
+package hello.jooq;
+
+import org.jooq.Record;
+import org.jooq.Result;
+import org.junit.jupiter.api.Test;
+
+import java.sql.ResultSet;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+
+class BookRepositoryTest {
+    @Test void getBooksPublishedInShouldReturnSomething() {
+        System.getProperties().setProperty("org.jooq.no-logo", "true");
+        BookRepository bookRepository = new BookRepository();
+        ResultSet resultSet = bookRepository.getBooksPublishedIn(1948);
+        assertNotNull(resultSet, "getBooksPublishedIn should return an object");
+    }
+
+    @Test void getAuthorsShouldReturnSomething() {
+        System.getProperties().setProperty("org.jooq.no-logo", "true");
+        BookRepository bookRepository = new BookRepository();
+        Result<Record> result = bookRepository.getAuthors();
+        assertNotNull(result, "getAuthors should return an object");
+    }
+}