It's awkward, since FB1.5 came out, I have never been deeply explored its new features, just when it is IB's continuation - as long as it is smooth, even if OK.
It's awkward, since FB1.5 came out, I have never been deeply explored its new features, just when it is IB's continuation - as long as it is smooth, even if OK. The previous two days ago, Firebird 1.5.2 has been supported. In my opinion, this is a fairly important feature in the relational database. Because using Case, you can generate a powerful data perspective - this thing seems to have a special name in Excel and other spreadsheets. . But it is definitely a very useful feature. Of course, we can use the spreadsheet software to implement this feature, but it will bring additional network communication burden, which is also a lot of calculation efficiency. The following is a perspective representation example written by the DEMO database Employee with FB:
select cust_no, sum (case when order_status = 'shipped' then 1 else 0 end) as Shipped, sum (case when order_status = 'open' then 1 else 0 end) as Open, sum (case when order_status = 'waiting' then 1 Else 0 end) as waitingfrom salesgroup by custom_no
It generated the result set with the order of each customer by processing status classification.
Because of the use of Case, you can generate a powerful data perspective - this thing seems to have a special name in Excel and other spreadsheets, forgetting it. But it is definitely a very useful feature. Of course, we can use the spreadsheet software to implement this feature, but it will bring additional network communication burden, which is also a lot of calculation efficiency. The following is a perspective representation example written by the DEMO database Employee with FB:
select cust_no, sum (case when order_status = 'shipped' then 1 else 0 end) as Shipped, sum (case when order_status = 'open' then 1 else 0 end) as Open, sum (case when order_status = 'waiting' then 1 Else 0 end) as waitingfrom salesgroup by custom_no
It generated the result set with the order of each customer by processing status classification.
