迁移达梦数据库适配LocalDateTime

问题

如果使用的是mybatis作为orm框架，那么当从mysql数据库切换到达梦数据库时，使用了LocalDateTime会报错。

Error attempting to get column 'create_time' from result set. Cause: dm.jdbc.driver.DMException: 不支持的接口或功能

根本原因是mybatis在转换LocalDateTime的时候发生了异常

解决办法

/**
 * 日期时间处理，适配达梦数据库
 */
@MappedTypes(LocalDateTime.class)
@MappedJdbcTypes(JdbcType.TIMESTAMP)
public class LocalDateTimeTypeHandler implements TypeHandler<LocalDateTime> {
    @Override
    public void setParameter(PreparedStatement preparedStatement, int i, LocalDateTime localDateTime, JdbcType jdbcType) throws SQLException {
        preparedStatement.setTimestamp(i, Timestamp.valueOf(localDateTime));
    }

    @Override
    public LocalDateTime getResult(ResultSet resultSet, String columnName) throws SQLException {
        Timestamp timestamp = resultSet.getTimestamp(columnName);
        return timestamp.toLocalDateTime();
    }

    @Override
    public LocalDateTime getResult(ResultSet resultSet, int columnIndex) throws SQLException {
        return resultSet.getTimestamp(columnIndex).toLocalDateTime();
    }

    @Override
    public LocalDateTime getResult(CallableStatement callableStatement, int columnIndex) throws SQLException {
        return callableStatement.getTimestamp(columnIndex).toLocalDateTime();
    }
}

全局注册TypeHandler

@Component
public class CustomTypeHandlerParser implements ApplicationContextAware {
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        //从spring容器获取sqlSessionFactory
        SqlSessionFactory sqlSessionFactory = applicationContext.getBean(SqlSessionFactory.class);
        //获取typeHandler注册器
        TypeHandlerRegistry typeHandlerRegistry = sqlSessionFactory.getConfiguration().getTypeHandlerRegistry();
        //注册typeHandler
        typeHandlerRegistry.register(LocalDateTime.class, LocalDateTimeTypeHandler.class);
    }
}

参考

1. Mybatis类型处理器
2. 达梦数据库迁移