Migrate db migration to flyway, use lowercase email

Author: gavlyukovskiy

build.gradle

@@ -29,6 +29,8 @@ dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-security'
     implementation 'org.springframework.boot:spring-boot-starter-validation'
     implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'org.flywaydb:flyway-core:11.13.0'
+    implementation 'org.flywaydb:flyway-database-postgresql:11.13.0'
 
     runtimeOnly 'org.postgresql:postgresql'
 

db/000-init.sql

@@ -2,8 +2,6 @@ services:
   postgres:
     image: postgres:17
     container_name: postgres
-    volumes:
-      - ./db:/docker-entrypoint-initdb.d
     environment:
       POSTGRES_USER: course_user
       POSTGRES_PASSWORD: course_user_password

db/schema/course.sql

@@ -31,7 +31,7 @@ public UserAccountEntity findByUserId(Integer userId) {
 
     @Nullable
     public UserAccountEntity findByEmailAddress(String emailAddress) {
-        String sql = "SELECT * FROM user_account WHERE email_address = :emailAddress";
+        String sql = "SELECT * FROM user_account WHERE lower(email_address) = lower(:emailAddress)";
         try {
             return jdbcTemplate.queryForObject(sql, Map.of("emailAddress", emailAddress), USER_ACCOUNT_ROW_MAPPER);
         } catch (EmptyResultDataAccessException e) {
@@ -60,7 +60,7 @@ public UserAccountEntity insertUserAccount(String emailAddress, String passwordH
 
     @Nullable
     public Integer findUserIdByEmail(String emailAddress) {
-        String sql = "SELECT user_id FROM user_account WHERE email_address = :emailAddress";
+        String sql = "SELECT user_id FROM user_account WHERE lower(email_address) = lower(:emailAddress)";
         try {
             return jdbcTemplate.queryForObject(sql, Map.of("emailAddress", emailAddress), Integer.class);
         } catch (EmptyResultDataAccessException e) {

db/schema/enrollment.sql

@@ -0,0 +1,55 @@
+-- User account (used for user authentication and authorization)
+CREATE TYPE role AS ENUM ('instructor', 'student');
+
+CREATE TABLE user_account
+(
+    user_id       INTEGER PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+    password_hash VARCHAR(60)  NOT NULL,
+    email_address VARCHAR(100) NOT NULL,
+    role          role         NOT NULL
+);
+
+-- preserve original email case for display, but enforce case-insensitive uniqueness
+CREATE UNIQUE INDEX idx_email_unique
+    ON user_account (lower(email_address));
+
+-- A student is a user who can enroll in courses.
+CREATE TABLE student
+(
+    student_id      INTEGER PRIMARY KEY,
+    first_name      VARCHAR NOT NULL,
+    last_name       VARCHAR NOT NULL,
+    enrollment_date DATE    NOT NULL DEFAULT current_date,
+    FOREIGN KEY (student_id) REFERENCES user_account (user_id) ON DELETE CASCADE
+);
+
+-- An instructor is a user who can create and manage courses.
+CREATE TABLE instructor
+(
+    instructor_id INTEGER PRIMARY KEY,
+    first_name    VARCHAR NOT NULL,
+    last_name     VARCHAR NOT NULL,
+    hire_date     DATE    NOT NULL DEFAULT current_date,
+    FOREIGN KEY (instructor_id) REFERENCES user_account (user_id) ON DELETE CASCADE
+);
+
+-- A course is taught by an instructor and can have many students enrolled.
+CREATE TABLE course
+(
+    course_id       INTEGER PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+    name            VARCHAR(255) NOT NULL,
+    description     TEXT,
+    instructor_id   INTEGER      REFERENCES instructor (instructor_id) ON DELETE SET NULL,
+    start_date      DATE,
+    end_date        DATE,
+    max_enrollments INT CHECK (max_enrollments > 0)
+);
+
+-- An enrollment is a student taking a course.
+CREATE TABLE enrollment
+(
+    enrollment_id   INTEGER PRIMARY KEY GENERATED ALWAYS AS IDENTITY,
+    student_id      INTEGER REFERENCES student (student_id) ON DELETE CASCADE,
+    course_id       INTEGER REFERENCES course (course_id) ON DELETE CASCADE,
+    enrollment_date DATE DEFAULT current_date
+);