java.sql.SQLSyntaxErrorException: Unknown database

❗️ 문제 상황

java.sql.SQLSyntaxErrorException: Unknown database 'stock_example'
	at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:121) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:825) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:446) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:239) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:188) ~[mysql-connector-j-8.0.33.jar:8.0.33]
	at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:359) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:201) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:470) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:561) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:100) ~[HikariCP-5.0.1.jar:na]
	at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) ~[HikariCP-5.0.1.jar:na]
	at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess.obtainConnection(JdbcEnvironmentInitiator.java:437) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcIsolationDelegate.delegateWork(JdbcIsolationDelegate.java:61) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.getJdbcEnvironmentUsingJdbcMetadata(JdbcEnvironmentInitiator.java:279) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:193) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:69) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:119) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:264) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:239) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:216) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.boot.model.relational.Database.<init>(Database.java:45) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.getDatabase(InFlightMetadataCollectorImpl.java:231) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:199) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:169) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1383) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1454) ~[hibernate-core-6.2.13.Final.jar:6.2.13.Final]
	at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:75) ~[spring-orm-6.0.13.jar:6.0.13]
	at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:376) ~[spring-orm-6.0.13.jar:6.0.13]
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-6.0.13.jar:6.0.13]
	at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-6.0.13.jar:6.0.13]
	at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:352) ~[spring-orm-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1817) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1766) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:598) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:520) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:325) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:323) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) ~[spring-beans-6.0.13.jar:6.0.13]
	at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1166) ~[spring-context-6.0.13.jar:6.0.13]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:940) ~[spring-context-6.0.13.jar:6.0.13]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:616) ~[spring-context-6.0.13.jar:6.0.13]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.1.5.jar:3.1.5]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:738) ~[spring-boot-3.1.5.jar:3.1.5]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:440) ~[spring-boot-3.1.5.jar:3.1.5]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-3.1.5.jar:3.1.5]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-3.1.5.jar:3.1.5]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-3.1.5.jar:3.1.5]
	at com.example.stockstudy.StockstudyApplication.main(StockstudyApplication.java:10) ~[main/:na]

🔍 문제 원인

사실 해결 방법은 그냥 간단하다. 그냥 해당 데이터베이스를 mysql에 만들어주면 된다. 하지만 나의 경우 mysql이 이미 깔려 있었는데 최근 터미널에 다시 Mysql을 설치한 것이 어떠한 문제를 일으켜 터미널의 MySql과 Workbench의 데이터가 이분화 되었다.
그 결과 프로그램을 돌릴 때 mysql workbench에서는 데이터를 사용할 수 없고 터미널에서만 사용할 수 있게 되었다.........

✅ 해결 방안

1. terminal 켜기
2. cd /usr/local/mysql/bin
3. ./mysql -u root -p (관리자 계정으로 접속, password창이 뜨면 눌러 준다.)
4. create database [데이터베이스이름];

아주 간단하다.