비트마스킹에서 큰 어려움을 겪고 있는 한 학생입니다...위 코드를 제가 제대로 이해했나 궁금해서 질문드립니다.k를 구하는 이유: s의 비트를 확인하기 위해선a와 같은 2차원 배열일 땐 확인을 할 수 없어서 일차원으로 풀어주기 위해서 k를 구하는 걸까요? 위 코드에서 처럼 적으면 모든 경우를 구할 수 있다고 하셨는데 혹시 한번만 더 풀어서 설명해주실 수 있을까요..? 개념 강의를 계속 돌려봐도 뭔가 시원하지가 않습니다!ㅠㅠ

섹션 9 값 타입 부분의 값 타입과 불변 객체 실습을 진행하고 있는데 계속 다음과 같은 에러가 떠서 아래와 같이 첨부합니다 8월 23, 2023 5:18:29 오후 org.hibernate.jpa.internal.util.LogHelper logPersistenceUnitInformationINFO: HHH000204: Processing PersistenceUnitInfo [ name: hello ...]8월 23, 2023 5:18:29 오후 org.hibernate.Version logVersionINFO: HHH000412: Hibernate Core {5.3.10.Final}8월 23, 2023 5:18:29 오후 org.hibernate.cfg.Environment <clinit>INFO: HHH000206: hibernate.properties not found8월 23, 2023 5:18:30 오후 org.hibernate.annotations.common.reflection.java.JavaReflectionManager <clinit>INFO: HCANN000001: Hibernate Commons Annotations {5.0.4.Final}8월 23, 2023 5:18:33 오후 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configureWARN: HHH10001002: Using Hibernate built-in connection pool (not for production use!)8월 23, 2023 5:18:33 오후 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreatorINFO: HHH10001005: using driver [org.h2.Driver] at URL [jdbc:h2:tcp://localhost/~/test]8월 23, 2023 5:18:33 오후 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreatorINFO: HHH10001001: Connection properties: {user=sa}8월 23, 2023 5:18:33 오후 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl buildCreatorINFO: HHH10001003: Autocommit mode: false8월 23, 2023 5:18:33 오후 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections <init>INFO: HHH000115: Hibernate connection pool size: 20 (min=1)8월 23, 2023 5:18:33 오후 org.hibernate.dialect.Dialect <init>INFO: HHH000400: Using dialect: org.hibernate.dialect.H2DialectHibernate: drop table Child if existsHibernate: drop table Item if existsHibernate: drop table Member if exists8월 23, 2023 5:18:35 오후 org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnectionINFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@5db6b845] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.8월 23, 2023 5:18:35 오후 org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleExceptionWARN: GenerationTarget encountered exception accepting command : Error executing DDL " drop table Member if exists" via JDBC Statementorg.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL " drop table Member if exists" via JDBC Statement at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:375) at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:359) at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:241) at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:154) at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:126) at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:112) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:144) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:310) at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:56) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54) at hellojpa.JpaMain.main(JpaMain.java:15)Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Cannot drop "MEMBER" because "FKJNJ8UNGT7V35Y6LFXUXCRJBBR" depends on it; SQL statement: drop table Member if exists [90107-200] at org.h2.message.DbException.getJdbcSQLException(DbException.java:576) at org.h2.message.DbException.getJdbcSQLException(DbException.java:429) at org.h2.message.DbException.get(DbException.java:205) at org.h2.command.ddl.DropTable.prepareDrop(DropTable.java:98) at org.h2.command.ddl.DropTable.update(DropTable.java:124) at org.h2.command.CommandContainer.update(CommandContainer.java:198) at org.h2.command.Command.executeUpdate(Command.java:251) at org.h2.server.TcpServerThread.process(TcpServerThread.java:406) at org.h2.server.TcpServerThread.run(TcpServerThread.java:183) at java.base/java.lang.Thread.run(Thread.java:833) at org.h2.message.DbException.getJdbcSQLException(DbException.java:573) at org.h2.engine.SessionRemote.done(SessionRemote.java:607) at org.h2.command.CommandRemote.executeUpdate(CommandRemote.java:237) at org.h2.jdbc.JdbcStatement.executeInternal(JdbcStatement.java:233) at org.h2.jdbc.JdbcStatement.execute(JdbcStatement.java:205) at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ... 15 more8월 23, 2023 5:18:35 오후 org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleExceptionWARN: GenerationTarget encountered exception accepting command : Error executing DDL " drop table Team if exists" via JDBC Statementorg.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL " drop table Team if exists" via JDBC Statement at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlString(SchemaDropperImpl.java:375) at org.hibernate.tool.schema.internal.SchemaDropperImpl.applySqlStrings(SchemaDropperImpl.java:359) at org.hibernate.tool.schema.internal.SchemaDropperImpl.dropFromMetadata(SchemaDropperImpl.java:241) at org.hibernate.tool.schema.internal.SchemaDropperImpl.performDrop(SchemaDropperImpl.java:154) at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:126) at org.hibernate.tool.schema.internal.SchemaDropperImpl.doDrop(SchemaDropperImpl.java:112) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:144) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:310) at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:56) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54) at hellojpa.JpaMain.main(JpaMain.java:15)Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Cannot drop "TEAM" because "FKL7WSNY760HJY6X19KQNDUASBM" depends on it; SQL statement: drop table Team if exists [90107-200] at org.h2.message.DbException.getJdbcSQLException(DbException.java:576) at org.h2.message.DbException.getJdbcSQLException(DbException.java:429) at org.h2.message.DbException.get(DbException.java:205) at org.h2.command.ddl.DropTable.prepareDrop(DropTable.java:98) at org.h2.command.ddl.DropTable.update(DropTable.java:124) at org.h2.command.CommandContainer.update(CommandContainer.java:198) at org.h2.command.Command.executeUpdate(Command.java:251) at org.h2.server.TcpServerThread.process(TcpServerThread.java:406) at org.h2.server.TcpServerThread.run(TcpServerThread.java:183) at java.base/java.lang.Thread.run(Thread.java:833) at org.h2.message.DbException.getJdbcSQLException(DbException.java:573) at org.h2.engine.SessionRemote.done(SessionRemote.java:607) at org.h2.command.CommandRemote.executeUpdate(CommandRemote.java:237) at org.h2.jdbc.JdbcStatement.executeInternal(JdbcStatement.java:233) at org.h2.jdbc.JdbcStatement.execute(JdbcStatement.java:205) at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ... 15 moreHibernate: drop table MemberProduct if existsHibernate: drop table Parent if existsHibernate: drop table Product if existsHibernate: drop table Team if existsHibernate: drop sequence if exists hibernate_sequenceHibernate: create sequence hibernate_sequence start with 1 increment by 1Hibernate: create table Child ( id bigint not null, name varchar(255), parent_id bigint, primary key (id) )Hibernate: create table Item ( DTYPE varchar(31) not null, id bigint not null, name varchar(255), price integer not null, artist varchar(255), author varchar(255), isbn varchar(255), actor varchar(255), director varchar(255), primary key (id) )Hibernate: create table Member ( MEMBER_ID bigint not null, city varchar(255), street varchar(255), ZIPCODE varchar(255), USERNAME varchar(255), endDate timestamp, startDate timestamp, TEAM_ID bigint, primary key (MEMBER_ID) )Hibernate: create table MemberProduct ( id bigint not null, count integer not null, orderDateTime timestamp, price integer not null, MEMBER_ID bigint, PRODUCT_ID bigint, primary key (id) )Hibernate: create table Parent ( id bigint not null, name varchar(255), primary key (id) )8월 23, 2023 5:18:35 오후 org.hibernate.resource.transaction.backend.jdbc.internal.DdlTransactionIsolatorNonJtaImpl getIsolatedConnectionINFO: HHH10001501: Connection obtained from JdbcConnectionAccess [org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator$ConnectionProviderJdbcConnectionAccess@29a98d9f] for (non-JTA) DDL execution was not in auto-commit mode; the Connection 'local transaction' will be committed and the Connection will be set into auto-commit mode.8월 23, 2023 5:18:35 오후 org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleExceptionWARN: GenerationTarget encountered exception accepting command : Error executing DDL " create table Member ( MEMBER_ID bigint not null, city varchar(255), street varchar(255), ZIPCODE varchar(255), USERNAME varchar(255), endDate timestamp, startDate timestamp, TEAM_ID bigint, primary key (MEMBER_ID) )" via JDBC Statementorg.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL " create table Member ( MEMBER_ID bigint not null, city varchar(255), street varchar(255), ZIPCODE varchar(255), USERNAME varchar(255), endDate timestamp, startDate timestamp, TEAM_ID bigint, primary key (MEMBER_ID) )" via JDBC Statement at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:440) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:424) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:315) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:166) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:135) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:121) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:155) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:310) at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:56) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54) at hellojpa.JpaMain.main(JpaMain.java:15)Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "MEMBER" already exists; SQL statement: create table Member ( MEMBER_ID bigint not null, city varchar(255), street varchar(255), ZIPCODE varchar(255), USERNAME varchar(255), endDate timestamp, startDate timestamp, TEAM_ID bigint, primary key (MEMBER_ID) ) [42101-200] at org.h2.message.DbException.getJdbcSQLException(DbException.java:453) at org.h2.message.DbException.getJdbcSQLException(DbException.java:429) at org.h2.message.DbException.get(DbException.java:205) at org.h2.message.DbException.get(DbException.java:181) at org.h2.command.ddl.CreateTable.update(CreateTable.java:89) at org.h2.command.CommandContainer.update(CommandContainer.java:198) at org.h2.command.Command.executeUpdate(Command.java:251) at org.h2.server.TcpServerThread.process(TcpServerThread.java:406) at org.h2.server.TcpServerThread.run(TcpServerThread.java:183) at java.base/java.lang.Thread.run(Thread.java:833) at org.h2.message.DbException.getJdbcSQLException(DbException.java:451) at org.h2.engine.SessionRemote.done(SessionRemote.java:607) at org.h2.command.CommandRemote.executeUpdate(CommandRemote.java:237) at org.h2.jdbc.JdbcStatement.executeInternal(JdbcStatement.java:233) at org.h2.jdbc.JdbcStatement.execute(JdbcStatement.java:205) at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ... 15 more8월 23, 2023 5:18:35 오후 org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleExceptionWARN: GenerationTarget encountered exception accepting command : Error executing DDL " create table Team ( TEAM_ID bigint not null, INSERT_MEMBER varchar(255), createdDate timestamp, UPDATE_MEMBER varchar(255), lastModifiedDate timestamp, name varchar(255), primary key (TEAM_ID) )" via JDBC Statementorg.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL " create table Team ( TEAM_ID bigint not null, INSERT_MEMBER varchar(255), createdDate timestamp, UPDATE_MEMBER varchar(255), lastModifiedDate timestamp, name varchar(255), primary key (TEAM_ID) )" via JDBC Statement at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:440) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:424) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:315) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:166) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:135) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:121) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:155) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:310) at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:56) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54) at hellojpa.JpaMain.main(JpaMain.java:15)Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Table "TEAM" already exists; SQL statement: create table Team ( TEAM_ID bigint not null, INSERT_MEMBER varchar(255), createdDate timestamp, UPDATE_MEMBER varchar(255), lastModifiedDate timestamp, name varchar(255), primary key (TEAM_ID) ) [42101-200] at org.h2.message.DbException.getJdbcSQLException(DbException.java:453) at org.h2.message.DbException.getJdbcSQLException(DbException.java:429) at org.h2.message.DbException.get(DbException.java:205) at org.h2.message.DbException.get(DbException.java:181) at org.h2.command.ddl.CreateTable.update(CreateTable.java:89) at org.h2.command.CommandContainer.update(CommandContainer.java:198) at org.h2.command.Command.executeUpdate(Command.java:251) at org.h2.server.TcpServerThread.process(TcpServerThread.java:406) at org.h2.server.TcpServerThread.run(TcpServerThread.java:183) at java.base/java.lang.Thread.run(Thread.java:833) at org.h2.message.DbException.getJdbcSQLException(DbException.java:451) at org.h2.engine.SessionRemote.done(SessionRemote.java:607) at org.h2.command.CommandRemote.executeUpdate(CommandRemote.java:237) at org.h2.jdbc.JdbcStatement.executeInternal(JdbcStatement.java:233) at org.h2.jdbc.JdbcStatement.execute(JdbcStatement.java:205) at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ... 15 moreHibernate: create table Product ( id bigint not null, name varchar(255), primary key (id) )Hibernate: create table Team ( TEAM_ID bigint not null, INSERT_MEMBER varchar(255), createdDate timestamp, UPDATE_MEMBER varchar(255), lastModifiedDate timestamp, name varchar(255), primary key (TEAM_ID) )Hibernate: alter table Child add constraint FKlh67j1n7x7gt59u0pbkwqh6o6 foreign key (parent_id) references ParentHibernate: alter table Member add constraint FKl7wsny760hjy6x19kqnduasbm foreign key (TEAM_ID) references TeamHibernate: alter table MemberProduct add constraint FKjnj8ungt7v35y6lfxuxcrjbbr foreign key (MEMBER_ID) references MemberHibernate: alter table MemberProduct add constraint FKrgt6jorh7iaec1tae84ljye8c foreign key (PRODUCT_ID) references Product8월 23, 2023 5:18:35 오후 org.hibernate.tool.schema.internal.ExceptionHandlerLoggedImpl handleExceptionWARN: GenerationTarget encountered exception accepting command : Error executing DDL " alter table Member add constraint FKl7wsny760hjy6x19kqnduasbm foreign key (TEAM_ID) references Team" via JDBC Statementorg.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL " alter table Member add constraint FKl7wsny760hjy6x19kqnduasbm foreign key (TEAM_ID) references Team" via JDBC Statement at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:440) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:424) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:375) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:166) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:135) at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:121) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:155) at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:310) at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:467) at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:939) at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:56) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54) at hellojpa.JpaMain.main(JpaMain.java:15)Caused by: org.h2.jdbc.JdbcSQLSyntaxErrorException: Constraint "FKL7WSNY760HJY6X19KQNDUASBM" already exists; SQL statement: alter table Member add constraint FKl7wsny760hjy6x19kqnduasbm foreign key (TEAM_ID) references Team [90045-200] at org.h2.message.DbException.getJdbcSQLException(DbException.java:576) at org.h2.message.DbException.getJdbcSQLException(DbException.java:429) at org.h2.message.DbException.get(DbException.java:205) at org.h2.message.DbException.get(DbException.java:181) at org.h2.command.ddl.AlterTableAddConstraint.tryUpdate(AlterTableAddConstraint.java:114) at org.h2.command.ddl.AlterTableAddConstraint.update(AlterTableAddConstraint.java:78) at org.h2.command.CommandContainer.update(CommandContainer.java:198) at org.h2.command.Command.executeUpdate(Command.java:251) at org.h2.server.TcpServerThread.process(TcpServerThread.java:406) at org.h2.server.TcpServerThread.run(TcpServerThread.java:183) at java.base/java.lang.Thread.run(Thread.java:833) at org.h2.message.DbException.getJdbcSQLException(DbException.java:573) at org.h2.engine.SessionRemote.done(SessionRemote.java:607) at org.h2.command.CommandRemote.executeUpdate(CommandRemote.java:237) at org.h2.jdbc.JdbcStatement.executeInternal(JdbcStatement.java:233) at org.h2.jdbc.JdbcStatement.execute(JdbcStatement.java:205) at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:54) ... 15 more8월 23, 2023 5:18:35 오후 org.hibernate.tool.schema.internal.SchemaCreatorImpl applyImportSourcesINFO: HHH000476: Executing import script 'org.hibernate.tool.schema.internal.exec.ScriptSourceInputNonExistentImpl@45cec376'Hibernate: call next value for hibernate_sequenceHibernate: call next value for hibernate_sequenceHibernate: /* insert hellojpa.Member */ insert into Member (city, street, ZIPCODE, USERNAME, endDate, startDate, MEMBER_ID) values (?, ?, ?, ?, ?, ?, ?)Hibernate: /* insert hellojpa.Member */ insert into Member (city, street, ZIPCODE, USERNAME, endDate, startDate, MEMBER_ID) values (?, ?, ?, ?, ?, ?, ?)8월 23, 2023 5:18:36 오후 org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl releaseINFO: HHH000010: On release of batch it still contained JDBC statements8월 23, 2023 5:18:36 오후 org.hibernate.engine.jdbc.batch.internal.BatchingBatch performExecutionERROR: HHH000315: Exception executing batch [org.h2.jdbc.JdbcBatchUpdateException: Unique index or primary key violation: "PRIMARY KEY ON PUBLIC.MEMBER(MEMBER_ID) [2, 'newCity', 'street', '10000', 'member2', NULL, NULL, NULL]"; SQL statement:/* insert hellojpa.Member / insert into Member (city, street, ZIPCODE, USERNAME, endDate, startDate, MEMBER_ID) values (?, ?, ?, ?, ?, ?, ?) [23505-199]], SQL: / insert hellojpa.Member */ insert into Member (city, street, ZIPCODE, USERNAME, endDate, startDate, MEMBER_ID) values (?, ?, ?, ?, ?, ?, ?)8월 23, 2023 5:18:36 오후 org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptionsWARN: SQL Error: 23505, SQLState: 235058월 23, 2023 5:18:36 오후 org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptionsERROR: Unique index or primary key violation: "PRIMARY KEY ON PUBLIC.MEMBER(MEMBER_ID) [2, 'newCity', 'street', '10000', 'member2', NULL, NULL, NULL]"; SQL statement:/* insert hellojpa.Member */ insert into Member (city, street, ZIPCODE, USERNAME, endDate, startDate, MEMBER_ID) values (?, ?, ?, ?, ?, ?, ?) [23505-199]8월 23, 2023 5:18:36 오후 org.hibernate.engine.jdbc.spi.SqlExceptionHelper logExceptionsERROR: Unique index or primary key violation: "PRIMARY KEY ON PUBLIC.MEMBER(MEMBER_ID) [1, 'newCity', 'street', '10000', 'member1', NULL, NULL, NULL]"; SQL statement:/* insert hellojpa.Member */ insert into Member (city, street, ZIPCODE, USERNAME, endDate, startDate, MEMBER_ID) values (?, ?, ?, ?, ?, ?, ?) [23505-199]8월 23, 2023 5:18:36 오후 org.hibernate.internal.ExceptionMapperStandardImpl mapManagedFlushFailureERROR: HHH000346: Error during managed flush [org.hibernate.exception.ConstraintViolationException: could not execute batch]javax.persistence.RollbackException: Error while committing the transaction at org.hibernate.internal.ExceptionConverterImpl.convertCommitException(ExceptionConverterImpl.java:81) at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:107) at hellojpa.JpaMain.main(JpaMain.java:39)Caused by: javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: could not execute batch at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:154) at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:181) at org.hibernate.internal.ExceptionConverterImpl.convertCommitException(ExceptionConverterImpl.java:65) ... 2 moreCaused by: org.hibernate.exception.ConstraintViolationException: could not execute batch at org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:112) at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42) at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:113) at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.performExecution(BatchingBatch.java:129) at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.doExecuteBatch(BatchingBatch.java:105) at org.hibernate.engine.jdbc.batch.internal.AbstractBatchImpl.execute(AbstractBatchImpl.java:147) at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.executeBatch(JdbcCoordinatorImpl.java:212) at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:633) at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:478) at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:356) at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39) at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1454) at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:511) at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3290) at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2486) at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:473) at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:178) at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$300(JdbcResourceLocalTransactionCoordinatorImpl.java:39) at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:271) at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:104) ... 1 moreCaused by: org.h2.jdbc.JdbcBatchUpdateException: Unique index or primary key violation: "PRIMARY KEY ON PUBLIC.MEMBER(MEMBER_ID) [2, 'newCity', 'street', '10000', 'member2', NULL, NULL, NULL]"; SQL statement:/* insert hellojpa.Member */ insert into Member (city, street, ZIPCODE, USERNAME, endDate, startDate, MEMBER_ID) values (?, ?, ?, ?, ?, ?, ?) [23505-199] at org.h2.jdbc.JdbcPreparedStatement.executeBatch(JdbcPreparedStatement.java:1298) at org.hibernate.engine.jdbc.batch.internal.BatchingBatch.performExecution(BatchingBatch.java:119) ... 17 more8월 23, 2023 5:18:36 오후 org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl stopINFO: HHH10001008: Cleaning up connection pool [jdbc:h2:tcp://localhost/~/test]Process finished with exit code 0 참고로 이전에 create-drop을 사용해 테이블을 삭제했습니다.

안녕하세요, 문제 먼저 풀어보고 강의 들으면서 이해가 안되는게 생겨서 질문합니다.혼자 문제를 풀 때 계속 Segmentation fault 라고 떠서 이해가 안됐는데 강의를 보고 처음 전역변수 선언을 vector<int> a 에서 int a[9] 로 바꿨더니 정상적으로 작동합니다. 혹시 무슨 이유 때문인지 알 수 있을까요??http://boj.kr/f29a4a0039a24e0cb80ca19bfe8a1209

DELETE FROM Person WHERE id IN( SELECT p2.id FROM Person AS p1 INNER JOIN Person AS p2 ON p1.email=p2.email WHERE p1.id<p2.id );저스스로 작성해본 코드입니다만위와 같이 작성 후 제출하면"You can't specify target table 'p' for update in FROM clause" 라고 뜨더라구요.저번 선생님께서 알려주신 NOT IN 을 사용한 코드와 거의 비슷한 방식인거 같은데 왜 위와같은 오류가 뜨는지 알 수 있을까요?

파일 업로드 예제를 진행하던 와중에.pdf 파일이나 동일하지만 사이즈가 작은 스크린샷 .png 까지는 정상적으로 업로드 되는데 올려드린 다음과 같은 파일을 업로드 시도하는 경우 whitelabel error 페이지가 뜨면서 업로드가 정상적으로 실행이 되지 않습니다 해당 파일의 메타데이터는 다음과 같은데.... 2023-08-23 17:00:14.790 ERROR 9800 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.multipart.MaxUploadSizeExceededException: Maximum upload size exceeded; nested exception is java.lang.IllegalStateException: org.apache.tomcat.util.http.fileupload.impl.FileSizeLimitExceededException: The field file exceeds its maximum permitted size of 1048576 bytes.] with root cause 다음과 같은 이유였네요 생각보다 스프링이 기본적으로 허용하는 사이즈가 작은가봅니다 혹시라도 다른분이 도움되실까 싶어 남겨놓겠습니다

안녕하세요~해당강의 엑셀 버젼이 어떻게 되나요?강의 소개에서 못본거 같아서요. 감사합니다

코드도 다 맞게 입력했는데 년도, 날짜는 다 정상적으로데이터가 저장이 되는데 현재 시간만 이상하게 저장됩니다. 현재 시간이 16시인데 07시라고만 뜨네요 왜이런걸까요 ???

똑같이 한거 같은데 오류가 나네요..뒷부분을 진행 못하고 있습니다 ㅠ <작성한 코드>#pragma once#define DECLARE_SINGLE(classname) ₩private: ₩classname() {} ₩public: ₩static classname* GetInstance() ₩{ static classname s_instance; ₩return &s_instance; ₩} 

@Slf4j 롬복을 이용하여 log값을 출력할때,맨 위 클래스에 작성하고 사용하지 않고 클래스 위에 각각 @Slf4j를 작성하는 이유는 무엇인지 궁금합니다.

학습하는 분들께 도움이 되고, 더 좋은 답변을 드릴 수 있도록 질문전에 다음을 꼭 확인해주세요.1. 강의 내용과 관련된 질문을 남겨주세요.2. 인프런의 질문 게시판과 자주 하는 질문(링크)을 먼저 확인해주세요.(자주 하는 질문 링크: https://bit.ly/3fX6ygx)3. 질문 잘하기 메뉴얼(링크)을 먼저 읽어주세요.(질문 잘하기 메뉴얼 링크: https://bit.ly/2UfeqCG)질문 시에는 위 내용은 삭제하고 다음 내용을 남겨주세요.=========================================[질문 템플릿]1. 강의 내용과 관련된 질문인가요? (예/아니오)2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? (예/아니오)3. 질문 잘하기 메뉴얼을 읽어보셨나요? (예/아니오)[질문 내용]여기에 질문 내용을 남겨주세요. 에러메시지가 다음과 같습니다.2023-08-23 16:17:14.544 ERROR 6412 --- [ restartedMain] j.LocalContainerEntityManagerFactoryBean : Failed to initialize JPA EntityManagerFactory: component: jpabook.jpashop.domain.Delivery property not found: id delivery랑 member쪽에 문제가 있는 것 같은데 원인을 모르겠네요...

void doSomething(const int& x){ cout << x << endl;}이 경우 값을 바로 넣어도 되기 때문에 굉장히 편해진다고 하시는데, 이 경우 굳이 const int x로 해도 똑같지 않나요??파라미터를 const int& x로 받으면 편해진다는 것이 잘 이해가 되지 않아 물어봅니다.

# 동영상 고정 크기로 설정 import cv2 cap = cv2.VideoCapture('video.mp4') while cap.isOpened(): ret, frame = cap.read() if not ret: break frame_resized = cv2.resize(frame, (400, 500)) cv2.imshow('video', frame_resized) if cv2.waitKey(1) == ord('q'): break cap.release() cv2.destroyAllWindows() #cv2.waitKey(1)# 동영상 비율 크기로 설정 import cv2 cap = cv2.VideoCapture('video.mp4') while cap.isOpened(): ret, frame = cap.read() if not ret: break frame_resized = cv2.resize(frame, None, fx = 1.5, fy = 1.5, interpolation = cv2.INTER_CUBIC) cv2.imshow('video', frame_resized) if cv2.waitKey(1) == ord('q'): break cap.release() cv2.destroyAllWindows() #cv2.waitKey(1) Mac OS 사용자 입니다. 마지막 'cv2.waitKey(1)' 코드는 맥의 경우 해당 코드를 추가하지 않았을 때에 python 출력 창이 닫히지를 않아 추가하게 된 코드입니다. cv2.waitKey(1) 추가 -> 실행 시, 출력 영상의 창이 1초 떴다가 사라짐 / 오류 코드 안 뜸cv2.waitKey(1) 삭제 -> 실행 시, 출력 영상의 창이 아예 안 뜸 / 오류 코드 안 뜸 강의 속 강사 님처럼 비율 조정이 된 영상이 정상적으로 출력이 되어야 하는데 저는 그렇지 않아서 혹시 해결방법을 아시는 분이 계실까 질문 해봅니다...ㅠㅠ 오류 코드도 안 뜨고 실행은 되는데 보여져야 할 출력 영상이 보이지 않아 답답합니다... 도와주세요

21:15초경 작성하신 코드대로 작성하고, 인증번호 전송을 여러번 클릭 할 경우 타이머 숫자가 버벅거리는 현상이 있는데, 이게 클릭 할 때 마다 3:00 타이머가 시작되어 여러개가 동시에 입력되어 발생하는 현상인가요? 맞다면 이 현상은 어떻게 해결하는지 궁금합니다.

[질문 템플릿]1. 강의 내용과 관련된 질문인가요? (예/아니오)2. 인프런의 질문 게시판과 자주 하는 질문에 없는 내용인가요? (예/아니오)3. 질문 잘하기 메뉴얼을 읽어보셨나요? (예/아니오)[질문 내용]코드@Entity public class Member { @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "member_id") private Long id; @ManyToOne @JoinColumn(name = "team_id") private Team team; // getter & setter }@Entity public class Team { @Id @GeneratedValue(strategy = IDENTITY) @Column(name = "team_id") private Long id; private String name; @OneToMany(mappedBy = "team") private List<Member> members; // getter & setter }public class Main { public static void main(String[] args) { try { tx.begin(); Team team = new Team(); team.setName("teamA"); em.persist(team); Member member = new Member(); member.setTeam(team); em.persist(member); em.flush(); em.clear(); System.out.println("1"); Member findMember = em.find(Member.class, member.id()); System.out.println("2"); Team membersTeam = findMember.team(); System.out.println("3"); List<Member> members = membersTeam.members(); System.out.println("4"); System.out.println("size = " + members.size()); // 이때 예상치 못한 select 문이 나가는 것으로 의심된다. 출력 결과는 1 tx.commit(); System.out.println("5"); } catch (Exception e) { // handle Exception } finally { // close EntityManager } } }양뱡향 연관관계 강의를 들으며 위와 같은 코드를 작성해보았습니다.실행 결과질문4번과 5번 사이에 아무런 쿼리문이 나가지 않는 것을 기대했습니다. 하지만 왜인지 Member 테이블에서 Team의 아이디로 Member를 조회하는 쿼리문이 나갑니다.제가 생각했을 땐 members.size()를 호출함으로써 나가는 것 같은데, 위 코드는 단순히 List 형 객체의 size를 List<Member> members 는 단순히 자바에서 List 형 객체 아닌가요? 이때 왜 조회 쿼리가 나가는지 잘 모르겠습니다.만약, 나가더라도 Member 테이블에서 membersTeam: Team 의 아이디로 count 쿼리가 나가야 정상적일 것 같습니다.어느 부분을 놓쳤을까요?

TxBasicTest에서proxyCheck에서 테스트를 돌리면 에러가 나옵니다기대값은 true인데 false가 나온다고합니다. package hello.springtx.apply; import lombok.extern.slf4j.Slf4j; import org.assertj.core.api.Assertions; import org.junit.jupiter.api.Test; import org.springframework.aop.support.AopUtils; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.test.context.SpringBootTest; import org.springframework.boot.test.context.TestConfiguration; import org.springframework.context.annotation.Bean; import org.springframework.transaction.support.TransactionSynchronizationManager; import static org.assertj.core.api.Assertions.assertThat; @Slf4j @SpringBootTest public class TxBasicTest { @Autowired BasicService basicService; @Test void proxyCheck(){ log.info("aop class={}", basicService.getClass()); assertThat(AopUtils.isAopProxy(basicService)).isTrue(); } @TestConfiguration static class TxApplyBasicConfig{ @Bean BasicService basicService(){ return new BasicService(); } } @Slf4j static class BasicService{ public void tx(){ log.info("call tx"); boolean txActive = TransactionSynchronizationManager.isActualTransactionActive(); log.info("tx active={}", txActive); } public void nonTx(){ log.info("call nonTx"); boolean txActive = TransactionSynchronizationManager.isActualTransactionActive(); log.info("nonTx active={}", txActive); } } }

DefaultConversionService 가 왜 ISP 원칙에 연관되어있는지 잘 이해가 가지 않아 질문드립니다. 결론적으로 ISP의 경우 인터페이스 분리 원칙, 클라이언트가 자신이 이용하지 않는 메서드에 의존하지 말아야한다인데DefaultConversionService의 경우 사용과 등록을 모두 사용하고 있습니다, 따라서 두 가지 기능을 모두 사용하게 되는데 결국 두개 다 사용하게 되면 애초에 인터페이스를 분할할 필요가 없게 되는것이 아닌지 궁금합니다. 두 개를 분리함으로써 얻게되는 이득에 대해서 다시 한번만 설명이 가능하실지 궁금합니다 ㅠㅠ 감사합니다!

구분에 대해 명확히 이해가 되지 않는데요,SOA 경우도 서비스 단위 개발이고 Microservice도 그렇지 않나요? 그 규모의 차이가 둘을 구분 짓는 건가요?ex) SOA의 서비스 단위가 숙박 예약 기능이라고 하면Microservice는 숙박조회, 결제 ... 으로 더 세분화 그리고 SOA에서 직접 서비스간에 데이터 교환을 하는 것에서 발생하는 의존 문제로 인해 ESB를 도입했다고 봤는데요, Microservice에서는 API를 통해 서비스 간 통신 시 이런 의존문제가 없을 수 있는건가요? 뭔가 구체적인 예시로 비교해주시면 감사하겠습니다.

github에 pull하고 push하는 것이 모두 에러가 뜹니다. 그래서 아예 초기화를 하려고 하는데 혹시 어떻게 해야 하나요  폴더에서 rm -rf git해서 지웠다 처음부터 해보고 remote도 지웠다가 다시 연결하는데도 문제가 계속 생깁니다. 그래서 아예 git자체를 완전히 토기화 하고 싶은데 어떻게 해야 하나요? 

tessilation 을 통해서 displacement mapping 을 좀 복잡한 mesh 에 적용을 해봤는데 gpu 가 갈리는 소리가 나서요. 아무래도 삼각형 개수가 기하급수적으로 늘다보니 gpu load 가 클거 같은데 tessilation 이 실제로 필요사양이 높은가요? 그리고 현업에서도 tessilation 사용하는데 제약이 많은지 궁금합니다.

안녕하세요 맛비님! 그렇게 중요하진 않아보이지만 항상 궁금했던 내용이라 질문드립니다. 예시로always @( posedge S_AXI_ACLK ) begin if ( S_AXI_ARESETN == 1'b0 ) begin axi_awaddr <= 0; end else begin if (~axi_awready && S_AXI_AWVALID && S_AXI_WVALID && aw_en) begin // Write Address latching axi_awaddr <= S_AXI_AWADDR; end end end 166번째 라인에 있는 코드인데 else if (~axi_awready && S_AXI_AWVALID && S_AXI_WVALID && aw_en) axi_awaddr <= S_AXI_AWADDR; end else if (~axi_awready && S_AXI_AWVALID && S_AXI_WVALID && aw_en) begin axi_awaddr <= S_AXI_AWADDR; end end  else부분을 이렇게 더 간결하게 짜면 좋을꺼같은데굳이 begin end로 묶는 이유가있을까요?가독성이 더 좋아지기 때문일까요?