项目架构
Springboot+PostgreSQL+MybatisPlus
从Mongodb转过来的项目,有存储json数据的需求,但是在mybatis-plus上会出点问题
报错: Error updating database. Cause: org.postgresql.util.PSQLException 字段 “” 的类型为 jsonb, 但表达式的类型为 character varying 建议:你需要重写或转换表达式
实体类定义:
@EqualsAndHashCode(callSuper = true)
@Data
@TableName("tb_user_role")
@FieldDefaults(level = AccessLevel.PRIVATE)
public class TbUserRole extends BaseEntity {
@TableField("user_id")
String userId;
@JsonInclude(JsonInclude.Include.NON_EMPTY)
List<String> roles; // 存储为 JSONB
@JsonInclude(JsonInclude.Include.NON_EMPTY)
List<String> permissions; // 存储为 JSONB
}
SQL
CREATE TABLE tb_user_role (
id VARCHAR(255) PRIMARY KEY, -- 主键ID,继承自 BaseEntity
user_id VARCHAR(255) NOT NULL, -- 用户ID
roles JSONB, -- 角色,存储为 JSONB 类型
permissions JSONB, -- 权限,存储为 JSONB 类型
deleted BOOLEAN DEFAULT FALSE, -- 逻辑删除标识
create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP, -- 创建时间
update_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP -- 更新时间
);
前端传入的结构
@Schema(description = "角色,传入的对象需要从Role接口获取")
List<String> roles;
@Schema(description = "权限,传入的对象需要从Permission接口获取")
List<String> permissions;
存储时的问题
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@1c1e6475]
2024-09-27 17:48:43.398 ERROR [tid] [sid] [pid] [nio-8050-exec-1] c.s.w.h.GlobalExceptionHandler@viewExceptionHandler:66 :
### Error updating database. Cause: org.postgresql.util.PSQLException: 错误: 字段 "roles" 的类型为 jsonb, 但表达式的类型为 character varying
建议:你需要重写或转换表达式
位置:117
### The error may exist in com/sgcchg/data/mapper/UserRoleMapper.java (best guess)
### The error may involve com.sgcchg.data.mapper.UserRoleMapper.insert-Inline
### The error occurred while setting parameters
### SQL: INSERT INTO tb_user_role ( id, user_id, roles, permissions, deleted, create_time, update_time ) VALUES ( ?, ?, ?, ?, ?, ?, ? )
### Cause: org.postgresql.util.PSQLException: 错误: 字段 "roles" 的类型为 jsonb, 但表达式的类型为 character varying
建议:你需要重写或转换表达式
位置:117
; bad SQL grammar []; nested exception is org.postgresql.util.PSQLException: 错误: 字段 "roles" 的类型为 jsonb, 但表达式的类型为 character varying
建议:你需要重写或转换表达式
位置:117 location: com.sgcchg.business.impl.user.UserServiceImpl:101
问题解决
修改Entity定义
@EqualsAndHashCode(callSuper = true)
@Data
@TableName("tb_user_role")
@FieldDefaults(level = AccessLevel.PRIVATE)
public class TbUserRole extends BaseEntity {
@TableField("user_id")
String userId;
@TableField(typeHandler = ListToStringTypeHandler.class)
@JsonInclude(JsonInclude.Include.NON_EMPTY)
List<String> roles; // 存储为 JSONB
@TableField(typeHandler = ListToStringTypeHandler.class)
@JsonInclude(JsonInclude.Include.NON_EMPTY)
List<String> permissions; // 存储为 JSONB
}
添加TypeHandler
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collections;
import java.util.List;
public class ListToStringTypeHandler extends BaseTypeHandler<List<String>> {
private static final ObjectMapper objectMapper = new ObjectMapper();
// @Override
// public void setNonNullParameter(PreparedStatement ps, int i, List<String> parameter, JdbcType jdbcType) throws SQLException {
// // 将 List 转为 JSON 字符串存储
// try {
// ps.setString(i, objectMapper.writeValueAsString(parameter));
// } catch (JsonProcessingException e) {
// throw new SQLException("Could not convert list to JSON", e);
// }
// }
@Override
public void setNonNullParameter(PreparedStatement ps, int i, List<String> parameter, JdbcType jdbcType) throws SQLException {
try {
String jsonString = objectMapper.writeValueAsString(parameter);
ps.setObject(i, jsonString, JdbcType.OTHER.TYPE_CODE); // 使用 JDBC 的 OTHER 类型插入 JSONB
} catch (JsonProcessingException e) {
throw new SQLException("Could not convert list to JSON", e);
}
}
@Override
public List<String> getNullableResult(ResultSet rs, String columnName) throws SQLException {
String json = rs.getString(columnName);
return parseJsonToList(json);
}
@Override
public List<String> getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
String json = rs.getString(columnIndex);
return parseJsonToList(json);
}
@Override
public List<String> getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
String json = cs.getString(columnIndex);
return parseJsonToList(json);
}
private List<String> parseJsonToList(String json) {
if (json == null || json.trim().isEmpty()) {
return Collections.emptyList();
}
try {
return objectMapper.readValue(json, List.class);
} catch (JsonProcessingException e) {
return Collections.emptyList();
}
}
}
保存数据
之后即可保存数据
在数据库中可看到: