Question

我有4张桌子：

表1： batch_info with columns batch_id, brew_date, beer_style_name

表2： brew_fermentation with columns batch_id (FK of batch_info), fermentor_name (FK of fermentor),.。

表3： fermentor with columns, fermentor_name, tank_volume

表4： Produced_amount with columns batch_id(FK of batch_info), produced_amount, date_transferred

当酿造啤酒时，我们将其输入表1和表2中。当啤酒完成发酵时，我们将数据输入表4 produce_amount。

我想创建一个看起来像这样的表

Fermentor # |  Batch_ID  |  Tank_Size  |  Date_Brewed  | Beer Style

F10.1           13001         10           2013-01-12      IPA

F20.2           NULL         20             NULL          EMPTY

我有以下SQL语句。

然而，它不会显示发酵罐表中的所有发酵罐，只显示目前含有其中某些物质的发酵罐。我想像上面那样填充表格。

SELECT brew_fermentation.fermentor_name AS "Fermentor #",
batch_info.batch_id AS "Batch Number", batch_info.beer_style_name AS
"Beer Style", batch_info.date_brewed AS "Date Brewed",
fermentor.tank_volume AS "BBLs"

FROM batch_info, fermentor, brew_fermentation

WHERE batch_info.batch_id = brew_fermentation.batch_id AND
brew_fermentation.fermentor_name=fermentor.fermentor_name AND

batch_info.batch_id NOT IN (SELECT produced_amount.batch_id FROM
produced_amount)

ORDER BY batch_info.date_brewed

Answer 1

将NOT IN替换为NOT EXISTS。

  ...
WHERE 
  batch_info.batch_id = brew_fermentation.batch_id 
  AND brew_fermentation.fermentor_name=fermentor.fermentor_name 
  AND NOT EXISTS (
    SELECT 1 FROM produced_amount WHERE batch_id = batch_info.batch_id
  )

多个表不填充Null

1 个答案: