continent_population('Australia') := 30; continent_population('Antarctica') := 90; continent_population('UK') := 50;
如何在PL / sql中的值之后对此数组进行排序?谢谢!
以下是从Sorting PL/SQL Collections开始适用于您的案例的示例.请查看该文章了解详细信息.
/* The sorting is done with sql thus these types have to be sql types. */ create type sortable_t is object( continent varchar2(32767),population number ); / create type sortable_table_t is table of sortable_t; / declare type continent_population_t is table of pls_integer index by varchar2(32767); continent_population continent_population_t; i varchar2(32767); sorted sortable_table_t := sortable_table_t(); begin /* Populate original data. */ continent_population('Australia') := 30; continent_population('Antarctica') := 90; continent_population('UK') := 50; continent_population('USA') := 50; /* Convert to a helper data type that is used for sorting. */ i := continent_population.first; while i is not null loop sorted.extend(1); sorted(sorted.last) := new sortable_t(i,continent_population(i)); i := continent_population.next(i); end loop; /* Show that the content is not sorted yet. */ dbms_output.put_line('Unsorted:'); for j in sorted.first .. sorted.last loop dbms_output.put_line(sorted(j).continent || ' = ' || sorted(j).population); end loop; /* Sorting with sql. */ select cast(multiset(select * from table(sorted) order by 2 asc,1 asc) as sortable_table_t) into sorted from dual; /* Show that the content is now sorted. */ dbms_output.put_line('Sorted by value:'); for j in sorted.first .. sorted.last loop dbms_output.put_line(sorted(j).continent || ' = ' || sorted(j).population); end loop; end; /
打印:
Unsorted: Antarctica = 90 Australia = 30 UK = 50 USA = 50 Sorted by value: Australia = 30 UK = 50 USA = 50 Antarctica = 90