Add new exercise WallStreetDbInitializer.java

Author: tboychuk

account-db-initializer/src/test/java/com/bobocode/AccountDbInitializerTest.java

@@ -55,7 +55,7 @@ public void testTableHasPrimaryKey() throws SQLException {
     }
 
     @Test
-    public void testPrimaryKeyBasedOnIdField() throws SQLException {
+    public void testPrimaryKeyHasCorrectName() throws SQLException {
         try (Connection connection = dataSource.getConnection()) {
             Statement statement = connection.createStatement();
             ResultSet resultSet = statement.executeQuery("SELECT * FROM INFORMATION_SCHEMA.CONSTRAINTS" +
@@ -69,7 +69,7 @@ public void testPrimaryKeyBasedOnIdField() throws SQLException {
     }
 
     @Test
-    public void testPrimaryKeyHasCorrectName() throws SQLException {
+    public void testPrimaryKeyBasedOnIdField() throws SQLException {
         try (Connection connection = dataSource.getConnection()) {
             Statement statement = connection.createStatement();
             ResultSet resultSet = statement.executeQuery("SELECT * FROM INFORMATION_SCHEMA.CONSTRAINTS" +

jdbc-util/src/main/java/com/bobocode/util/FileReader.java

@@ -0,0 +1,49 @@
+package com.bobocode.util;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Objects;
+import java.util.stream.Stream;
+
+import static java.util.stream.Collectors.joining;
+
+/**
+ * {@link FileReader} provides an API that allow to read whole file into a {@link String} by file name.
+ */
+public class FileReader {
+
+    /**
+     * Returns a {@link String} that contains whole text from the file specified by name.
+     *
+     * @param fileName a name of a text file
+     * @return string that holds whole file content
+     */
+    public static String readWholeFileFromResources(String fileName) {
+        Path filePath = createPathFromFileName(fileName);
+        try (Stream<String> fileLinesStream = openFileLinesStream(filePath)) {
+            return fileLinesStream.collect(joining("\n"));
+        }
+    }
+
+    private static Stream<String> openFileLinesStream(Path filePath) {
+        try {
+            return Files.lines(filePath);
+        } catch (IOException e) {
+            throw new FileReaderException("Cannot create stream of file lines!", e);
+        }
+    }
+
+    private static Path createPathFromFileName(String fileName) {
+        Objects.requireNonNull(fileName);
+        URL fileUrl = FileReader.class.getClassLoader().getResource(fileName);
+        try {
+            return Paths.get(fileUrl.toURI());
+        } catch (URISyntaxException e) {
+            throw new FileReaderException("Invalid file URL",e);
+        }
+    }
+}

jdbc-util/src/main/java/com/bobocode/util/FileReaderException.java

@@ -0,0 +1,7 @@
+package com.bobocode.util;
+
+public class FileReaderException extends RuntimeException {
+    public FileReaderException(String message, Exception e) {
+        super(message, e);
+    }
+}

pom.xml

@@ -14,6 +14,7 @@
         <module>jdbc-account-data</module>
         <module>product-dao</module>
         <module>account-db-initializer</module>
+        <module>wall-street-db-initializer</module>
     </modules>
 
     <properties>
@@ -46,6 +47,13 @@
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
             <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-all</artifactId>
+            <version>1.3</version>
+            <scope>test</scope>
         </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>

wall-street-db-initializer/README.MD

@@ -0,0 +1,26 @@
+# <img src="https://raw.githubusercontent.com/bobocode-projects/resources/master/image/logo_transparent_background.png" height=50/>Wall Street db initializer exercise :muscle:
+Improve your database design and SQL skills
+### Task
+`WallStreetDbInitializer` provides an API that allows to create(initialize) a database tables to store broker information,
+sales groups and its relations. Roughly speaking  each group consists of multiple brokers, and each broker can be 
+associated with more than one group. The job of initializer is to crate proper database tables.
+ 
+`WallStreetDbInitializer` contains a *javadoc* that specifies database requirements. **It already contains all required Java 
+implementation.** Your job is to  **implement SQL file** `table_initialization.sql`.
+
+The purpose of the task is to **design a database table following docs and naming convention and implement it using SQL**
+
+To verify your implementation, run `WallStreetDbInitializerTest.java`
+
+### Pre-conditions :heavy_exclamation_mark:
+You're supposed to be familiar with database design and naming convention, *JDBC API* and *SQL*
+
+### How to start :question:
+* Just clone the repository and start implementing the **todo** section, verify your changes by running tests
+* If you don't have enough knowledge about this domain, check out the [links below](#related-materials-information_source)
+* Don't worry if you got stuck, checkout the **exercise/completed** branch and see the final implementation
+ 
+### Related materials :information_source:
+ * [JDBC API basics tutorial](https://github.com/bobocode-projects/jdbc-api-tutorial/tree/master/jdbc-basics) <img src="https://raw.githubusercontent.com/bobocode-projects/resources/master/image/logo_transparent_background.png" height=20/>
+ 
+

wall-street-db-initializer/pom.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>jdbc-api-exercises</artifactId>
+        <groupId>com.bobocode</groupId>
+        <version>1.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>wall-street-db-initializer</artifactId>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.bobocode</groupId>
+            <artifactId>jdbc-util</artifactId>
+            <version>1.0-SNAPSHOT</version>
+        </dependency>
+    </dependencies>
+
+</project>

wall-street-db-initializer/src/main/java/com/bobocode/WallStreetDbInitializer.java

@@ -0,0 +1,36 @@
+package com.bobocode;
+
+import com.bobocode.util.FileReader;
+
+import javax.sql.DataSource;
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+/**
+ * {@link WallStreetDbInitializer} is an API that has only one method. It allow to create a database tables to store
+ * information about brokers and its sales groups.
+ */
+public class WallStreetDbInitializer {
+    private final static String TABLE_INITIALIZATION_SQL_FILE = "db/migration/table_initialization.sql"; // todo: see the file
+    private DataSource dataSource;
+
+    public WallStreetDbInitializer(DataSource dataSource) {
+        this.dataSource = dataSource;
+    }
+
+    /**
+     * Reads the SQL script form the file and executes it
+     *
+     * @throws SQLException
+     */
+    public void init() throws SQLException {
+        String createTablesSql = FileReader.readWholeFileFromResources(TABLE_INITIALIZATION_SQL_FILE);
+
+        try (Connection connection = dataSource.getConnection()) {
+            Statement statement = connection.createStatement();
+            statement.execute(createTablesSql);
+        }
+    }
+
+}

wall-street-db-initializer/src/main/resources/db/migration/table_initialization.sql

@@ -0,0 +1,28 @@
+/*
+
+WallStreet database should store information about brokers, sales groups and its relations.
+
+Each broker must have a unique username. First and last names are also mandatory.
+
+A sales group is a special group that has its own restrictions. Sale groups are used to organize the work of brokers.
+Each group mush have a unique name, transaction type (string), and max transaction amount (a number). All field are
+mandatory.
+
+A sales group can consists of more than one broker, while each broker can be associated with more than one sale group.
+
+  TECH NOTES AND NAMING CONVENTION
+- All tables, columns and constraints are named using "snake case" naming convention
+- All table names must be singular (e.g. "user", not "users")
+- All tables (except link tables) should have an id of type BIGINT, which is a primary key.
+- All primary key, foreign key, and unique constraint should be named according to the naming convention.
+- All link tables should have a composite key that consists of two foreign key columns
+
+- All primary keys should be named according to the following rule "PK_table_name"
+- All foreign keys should be named according to the following rule "FK_table_name_reference_table_name"
+- All alternative keys (unique) should be named according to the following rule "UQ_table_name_column_name"
+  If the key is composite (e.g. consists of two columns), the name should list all column names.
+  E.g. "UQ_table_name_column1_name_column2_name"
+
+*/
+
+-- TODO: write SQL script to create a database tables according to the requirements