Instructions for using Oracle function Listagg

Instructions for using Oracle function Listagg

At work, customers often come up with the requirement that they want to enumerate the dates one by one in a summary merge.

, the original data is this:

Customers want to be able to achieve such a summary consolidation:


So I usually use the Listagg function, but a lot of the online system is a comprehensive introduction Listagg the use of this function, looks very laborious. I'm here to explain briefly.

The statement that implements the requirement is this:
Select Name,
Listagg (Ddate, '/') within group (order by name) as Ddate
From AA
Group BY name

Things to note are as follows:
1. A scoring group is required, i.e. group by is required.
2. The first parameter of the Listagg function is the field that needs to be enumerated, that is, ddate; the second argument is the delimiter between the enumeration values, and it also needs to be sorted and grouped within group (order by name)

Instructions for using Oracle function Listagg