Question

如何查询id_konsul = 4的数据，如果相同，我如何从staflow获取最新的created_at？

示例

id  id_konsul   staflow created_at

1   4   1   21/05/2018 11.03
2   4   2   22/05/2018 11.03
3   4   3   23/05/2018 11.03
4   4   4   24/05/2018 11.03
5   4   5   25/05/2018 11.03
6   4   6   26/05/2018 11.03
7   4   7   27/05/2018 11.03
8   4   6   28/05/2018 11.03
9   4   7   29/05/2018 11.03
10  4   7   30/05/2018 11.03
11  4   8   31/05/2018 11.03

比我得到这个

id  id_konsul   staflow created_at
1   4   1   21/05/2018 11.03
2   4   2   22/05/2018 11.03
3   4   3   23/05/2018 11.03
4   4   4   24/05/2018 11.03
5   4   5   25/05/2018 11.03
8   4   6   28/05/2018 11.03
10  4   7   30/05/2018 11.03
11  4   8   31/05/2018 11.03

Answer 1

您可以使用INNER JOIN。

示例：

SELECT t0.* from {TABLE_NAME} AS t0 INNER JOIN {TABLE_NAME} t1 ON t0.staflow = t1.staflow WHERE t0.created_at > t1.created_at and t0.id_konsul = 4

Answer 2

请尝试此查询。

SELECT * FROM table_name WHERE id_konsul = 4 ORDER BY created_at DESC LIMIT 1;

Answer 3

要获取每个staflow属性的最新行，您可以使用自联接

private Response mapException(Throwable originalThrowable) throws Throwable {
    if (throwable instanceof WebApplicationException) {
        WebApplicationException webApplicationException = (WebApplicationException)throwable;
     }

    this.processingContext.routingContext().setMappedThrowable(throwable);
    waeResponse = webApplicationException.getResponse();
    if (waeResponse.hasEntity()) {
        LOGGER.log(java.util.logging.Level.FINE, LocalizationMessages.EXCEPTION_MAPPING_WAE_ENTITY(waeResponse.getStatus()), throwable);
        return waeResponse;
    }        

    long timestamp = this.tracingLogger.timestamp(ServerTraceEvent.EXCEPTION_MAPPING);
    ExceptionMapper mapper = this.runtime.exceptionMappers.findMapping(throwable);
}

或使用左连接

select a.*
from demo a
join (
    select id_konsul,staflow, max(created_at) created_at
    from demo
    where id_konsul = 4
    group by id_konsul, staflow
) b on a.staflow = b.staflow
    and a.id_konsul = b.id_konsul 
    and a.created_at = b.created_at;

Demo

要使用laravel的查询构建器编写上述查询，您可以使用以下引用

Laravel Eloquent select all rows with max created_at

Laravel - Get the last entry of each UID type

Laravel Eloquent group by most recent record

Answer 4

尝试此查询

SELECT * FROM test1 n 
WHERE created_at=(SELECT MAX(created_at)FROM test1 
  WHERE staflow=n.staflow) 
order by id

如何使用`created_at`列获取最新数据

4 个答案: