WINDOW FUNCTION FIRST_VALUE
Description
This function returns the first value in the window.
FIRST_VALUE(expr) OVER(partition_by_clause order_by_clause [window_clause])Example
Supposing that you have the following data
select name, country, greeting from mail_merge;
| name | country | greeting |
|---------|---------|--------------|
| Pete | USA | Hello |
| John | USA | Hi |
| Boris | Germany | Guten tag |
| Michael | Germany | Guten morgen |
| Bjorn | Sweden | Hej |
| Mats | Sweden | Tja |Use FIRST_VALUE() to group the data by country and return the first greeting of each group:
select country, name,
first_value(greeting)
over (partition by country order by name, greeting) as greeting from mail_merge;
| country | name | greeting |
|---------|---------|-----------|
| Germany | Boris | Guten tag |
| Germany | Michael | Guten tag |
| Sweden | Bjorn | Hej |
| Sweden | Mats | Hej |
| USA | John | Hi |
| USA | Pete | Hi |Keywords
WINDOW,FUNCTION,FIRST_VALUE