SQL灵活查询结果

Question

我对SQL方面还很陌生。 我一直在尝试向您介绍条件，但是让它确定查询是否等于1个结果或多个结果。 我所拥有的如下。

我可能做错了所有，但以为我会问。

 SELECT employee_name
      , transaction_id
      , department
      , transaction_date
      , transaction_day
   FROM employee_transactions
  WHERE transaction_date 
BETWEEN '2018-08-20 07:14:35.000' 
    AND '2019-02-05 08:29:56.000'
    AND CASE WHEN '$variable' = 'All' 
             THEN inc_day IN (
                 SELECT DISTINCT transaction_day 
                   FROM employee_transactions
           ) ELSE inc_day in ('$variable')
             END

我的意思是在柱交易日中，有星期一，星期二，星期三等条目，但是都不在那里。 因此，在表单上，​​如果他们选择了全天的所有数据，而不只是一整天，但是如果他们选择了周一的数据，则只显示monda

Answer 1

您应该像下面这样编写查询。

SELECT employee_name, 
        transaction_id, 
        department, 
        transaction_date, 
        transaction_day

  FROM employee_transactions
  WHERE transaction_date 
  BETWEEN '2018-08-20 07:14:35.000' 
  AND '2019-02-05 08:29:56.000'
  AND ( '$variable' = 'All' OR inc_day = '$variable')

以上查询将在$ variable ='ALL'时返回所有记录，否则仅匹配记录。

假设在查询执行之前“ $ variable”将被替换。

Answer 2

你可以这样尝试

if($variable == "All")
{ 
   $query = "SELECT employee_name, transaction_id , department , transaction_date , 
   transaction_day
   WHERE transaction_date BETWEEN '2018-08-20 07:14:35.000' AND '2019-02-05 08:29:56.000'
   GROUP BY transaction_date"
}
else
{
   $query = "SELECT employee_name, transaction_id , department , transaction_date , transaction_day
   FROM employee_transactions
   WHERE transaction_date BETWEEN '2018-08-20 07:14:35.000'  AND '2019-02-05 08:29:56.000'
   AND inc_day in ($variable)"
}