diff --git a/pom.xml b/pom.xml
index 61c5e3b..622e927 100644
--- a/pom.xml
+++ b/pom.xml
@@ -41,8 +41,29 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+
+        <!-- 3rd party -->
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <scope>provided</scope>
+        </dependency>
+
+        <!-- Database -->
+        <dependency>
+            <groupId>org.hsqldb</groupId>
+            <artifactId>hsqldb</artifactId>
+        </dependency>
 
         <!-- Tests -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter</artifactId>
diff --git a/src/main/java/eu/ztsh/wymiana/Main.java b/src/main/java/eu/ztsh/wymiana/Main.java
index 7687607..c6e067d 100644
--- a/src/main/java/eu/ztsh/wymiana/Main.java
+++ b/src/main/java/eu/ztsh/wymiana/Main.java
@@ -2,8 +2,12 @@ package eu.ztsh.wymiana;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.context.properties.ConfigurationPropertiesScan;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 
 @SpringBootApplication
+@EnableConfigurationProperties
+@ConfigurationPropertiesScan
 public class Main {
 
     public static void main(String[] args) {
diff --git a/src/main/java/eu/ztsh/wymiana/data/config/DatabaseConfiguration.java b/src/main/java/eu/ztsh/wymiana/data/config/DatabaseConfiguration.java
new file mode 100644
index 0000000..64ed335
--- /dev/null
+++ b/src/main/java/eu/ztsh/wymiana/data/config/DatabaseConfiguration.java
@@ -0,0 +1,54 @@
+package eu.ztsh.wymiana.data.config;
+
+import com.zaxxer.hikari.HikariConfig;
+import com.zaxxer.hikari.HikariDataSource;
+import org.hsqldb.persist.HsqlProperties;
+import org.hsqldb.server.Server;
+import org.hsqldb.server.ServerAcl;
+import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import java.io.IOException;
+
+@Configuration
+public class DatabaseConfiguration {
+
+    /**
+     * Create HSQL Database instance that is accessible from outside of application
+     *
+     * @return server instance
+     * @throws ServerAcl.AclFormatException when instantiating ServerAcl
+     * @throws IOException                  when instantiating ServerAcl
+     */
+    @Bean
+    public Server hsqlServer(HsqlDbProperties properties) throws ServerAcl.AclFormatException, IOException {
+        var server = new Server();
+        var props = new HsqlProperties();
+        props.setProperty("server.database.0", String.format("mem:%s", properties.name()));
+        props.setProperty("server.dbname.0", properties.name());
+        props.setProperty("server.no_system_exit", true);
+        props.setProperty("server.port", properties.port());
+        server.setProperties(props);
+        server.start();
+        return server;
+    }
+
+    /**
+     * As we manually create database instance, we need also create datasource instance.
+     * HSQL instance is passed to force spring to create {@link Server} before pool.
+     *
+     * @param dataSourceProperties spring.datasource.* properties
+     * @return datasource instance
+     */
+    @Bean
+    public HikariDataSource hikariDataSource(DataSourceProperties dataSourceProperties, Server ignore) {
+        var config = new HikariConfig();
+        config.setJdbcUrl(dataSourceProperties.getUrl());
+        config.setUsername(dataSourceProperties.getUsername());
+        config.setPassword(dataSourceProperties.getPassword());
+        config.setDriverClassName(dataSourceProperties.getDriverClassName());
+        return new HikariDataSource(config);
+    }
+
+}
diff --git a/src/main/java/eu/ztsh/wymiana/data/config/HsqlDbProperties.java b/src/main/java/eu/ztsh/wymiana/data/config/HsqlDbProperties.java
new file mode 100644
index 0000000..b510225
--- /dev/null
+++ b/src/main/java/eu/ztsh/wymiana/data/config/HsqlDbProperties.java
@@ -0,0 +1,8 @@
+package eu.ztsh.wymiana.data.config;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+@ConfigurationProperties("hsqldb")
+public record HsqlDbProperties(String name, int port) {
+
+}
diff --git a/src/main/java/eu/ztsh/wymiana/data/entity/CurrencyEntity.java b/src/main/java/eu/ztsh/wymiana/data/entity/CurrencyEntity.java
new file mode 100644
index 0000000..441b224
--- /dev/null
+++ b/src/main/java/eu/ztsh/wymiana/data/entity/CurrencyEntity.java
@@ -0,0 +1,23 @@
+package eu.ztsh.wymiana.data.entity;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Entity
+@Table(name = "currency")
+public class CurrencyEntity {
+
+    @Id
+    String pesel;
+    @Id
+    String symbol;
+    Double amount;
+
+}
diff --git a/src/main/java/eu/ztsh/wymiana/data/entity/UserEntity.java b/src/main/java/eu/ztsh/wymiana/data/entity/UserEntity.java
new file mode 100644
index 0000000..a77e3c7
--- /dev/null
+++ b/src/main/java/eu/ztsh/wymiana/data/entity/UserEntity.java
@@ -0,0 +1,29 @@
+package eu.ztsh.wymiana.data.entity;
+
+import jakarta.persistence.CascadeType;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.OneToMany;
+import jakarta.persistence.Table;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.List;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Entity
+@Table(name = "user")
+public class UserEntity {
+
+    @Id
+    String pesel;
+    String name;
+    String surname;
+
+    @OneToMany(cascade = CascadeType.ALL, mappedBy = "pesel")
+    List<CurrencyEntity> currencies;
+
+}
diff --git a/src/main/java/eu/ztsh/wymiana/data/repository/UserRepository.java b/src/main/java/eu/ztsh/wymiana/data/repository/UserRepository.java
new file mode 100644
index 0000000..e77f9e9
--- /dev/null
+++ b/src/main/java/eu/ztsh/wymiana/data/repository/UserRepository.java
@@ -0,0 +1,8 @@
+package eu.ztsh.wymiana.data.repository;
+
+import eu.ztsh.wymiana.data.entity.UserEntity;
+import org.springframework.data.repository.CrudRepository;
+
+public interface UserRepository extends CrudRepository<UserEntity, String> {
+
+}
diff --git a/src/main/resources/application.yaml b/src/main/resources/application.yaml
index e69de29..ae6306d 100644
--- a/src/main/resources/application.yaml
+++ b/src/main/resources/application.yaml
@@ -0,0 +1,13 @@
+hsqldb:
+  name: db
+  port: 9090
+
+spring:
+  datasource:
+    username: sa
+    password:
+    url: jdbc:hsqldb:hsql://localhost:${hsqldb.port}/${hsqldb.name}
+    driver-class-name: org.hsqldb.jdbc.JDBCDriver
+  jpa:
+    hibernate:
+      ddl-auto: create
diff --git a/src/test/java/.gitkeep b/src/test/java/.gitkeep
deleted file mode 100644
index e69de29..0000000
diff --git a/src/test/java/eu/ztsh/wymiana/data/repository/UserRepositoryTest.java b/src/test/java/eu/ztsh/wymiana/data/repository/UserRepositoryTest.java
new file mode 100644
index 0000000..1da3e81
--- /dev/null
+++ b/src/test/java/eu/ztsh/wymiana/data/repository/UserRepositoryTest.java
@@ -0,0 +1,49 @@
+package eu.ztsh.wymiana.data.repository;
+
+import eu.ztsh.wymiana.data.entity.CurrencyEntity;
+import eu.ztsh.wymiana.data.entity.UserEntity;
+import jakarta.transaction.Transactional;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+@ExtendWith(SpringExtension.class)
+class UserRepositoryTest {
+
+    private final UserRepository userRepository;
+
+    @Autowired
+    UserRepositoryTest(UserRepository userRepository) {
+        this.userRepository = userRepository;
+    }
+
+    @BeforeEach
+    void prepareTest() {
+        userRepository.deleteAll();
+    }
+
+    @Test
+    @Transactional
+    @DisplayName("Basic insert & get test")
+    void basicTest() {
+        var pesel = "00281018264";
+        var entity = new UserEntity(pesel, "Janina", "Kowalska",
+            List.of(new CurrencyEntity(pesel, "PLN", 20.10)));
+        userRepository.save(entity);
+        assertThat(userRepository.findById(pesel))
+            .isNotEmpty()
+            .get()
+            .usingRecursiveComparison()
+            .isEqualTo(entity);
+    }
+
+}