我正在尝试使用postgres数据库设置spring boot项目。我的实体是： -
用户
@Entity
public class User implements UserDetails {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="id", nullable = false, updatable = false)
private Long id;
private String username;
private String password;
private String firstName;
private String lastName;
@Column(name="email", nullable = false, updatable = false)
private String email;
private String phone;
private boolean enabled=true;
@OneToMany(mappedBy = "user", cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JsonIgnore
private Set<UserRole> userRoles = new HashSet<>();
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
public Set<UserRole> getUserRoles() {
return userRoles;
}
public void setUserRoles(Set<UserRole> userRoles) {
this.userRoles = userRoles;
}
@Override
public Collection<? extends GrantedAuthority> getAuthorities() {
Set<GrantedAuthority> authorites = new HashSet<>();
userRoles.forEach(ur -> authorites.add(new Authority(ur.getRole().getName())));
return authorites;
}
@Override
public boolean isAccountNonExpired() {
// TODO Auto-generated method stub
return true;
}
@Override
public boolean isAccountNonLocked() {
// TODO Auto-generated method stub
return true;
}
@Override
public boolean isCredentialsNonExpired() {
// TODO Auto-generated method stub
return true;
}
@Override
public boolean isEnabled() {
return enabled;
}
}
作用
@Entity
public class Role {
@Id
private int roleId;
private String name;
@OneToMany(mappedBy = "role", cascade=CascadeType.ALL, fetch=FetchType.LAZY)
private Set<UserRole> userRoles = new HashSet<>();
public int getRoleId() {
return roleId;
}
public void setRoleId(int roleId) {
this.roleId = roleId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Set<UserRole> getUserRoles() {
return userRoles;
}
public void setUserRoles(Set<UserRole> userRoles) {
this.userRoles = userRoles;
}
}
USER_ROLE
@Entity
@Table(name="user_role")
public class UserRole {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Long userRoleId;
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name="user_id")
private User user;
@ManyToOne(fetch = FetchType.EAGER)
@JoinColumn(name="role_id")
private Role role;
public UserRole(){}
public UserRole(User user, Role role) {
this.user = user;
this.role = role;
}
public Long getUserRoleId() {
return userRoleId;
}
public void setUserRoleId(Long userRoleId) {
this.userRoleId = userRoleId;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
public Role getRole() {
return role;
}
public void setRole(Role role) {
this.role = role;
}
}
和我的application.properties文件如下： -
server.port=5060
spring.thymeleaf.cache=false
spring.datasource.url=jdbc:postgresql://localhost:5432/pcms
spring.datasource.data-username=sagar
spring.datasource.password=sagar
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.PostgreSQL94Dialect
spring.jpa.properties.hibernate.temp.use_jdbc_metadata_defaults = false
所以每当我运行这个应用程序。 user_role和角色表在postgresql数据库上成功创建。但是用户实体会抛出异常。
错误说： -
2018-05-07 15:44:15.847 WARN 23619 --- [ restartedMain] o.h.t.s.i.ExceptionHandlerLoggedImpl : GenerationTarget encountered exception accepting command : Error executing DDL via JDBC Statement
org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing DDL via JDBC Statement
at org.hibernate.tool.schema.internal.exec.GenerationTargetToDatabase.accept(GenerationTargetToDatabase.java:67) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlString(SchemaCreatorImpl.java:440) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.applySqlStrings(SchemaCreatorImpl.java:424) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.createFromMetadata(SchemaCreatorImpl.java:375) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.performCreation(SchemaCreatorImpl.java:166) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:135) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.internal.SchemaCreatorImpl.doCreation(SchemaCreatorImpl.java:121) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.performDatabaseAction(SchemaManagementToolCoordinator.java:155) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.tool.schema.spi.SchemaManagementToolCoordinator.process(SchemaManagementToolCoordinator.java:72) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:312) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:460) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:892) [hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.0.1.RELEASE.jar:2.0.1.RELEASE]
Caused by: org.postgresql.util.PSQLException: ERROR: syntax error at or near "user"
Position: 108
您可以在USER实体上看到错误点。但是当应用程序连接到mysql数据库时，同一实体运行正常。我无法弄清楚它背后的真正错误是什么。
答案 0 :(得分：4)
User实际上是一个保留关键字，Spring JPA不会按原样“逃避”。但是，您可以在实体声明中执行关键字转义：
@Entity
@Table(name = "\"User\"")
public class User implements UserDetails { ... }
Spring可能会在你的MySql数据库中为你逃避它，或者以其他方式为你处理它;不是你的PostgreSQL数据库的情况。