{"id":5171,"date":"2015-06-20T12:56:42","date_gmt":"2015-06-20T10:56:42","guid":{"rendered":"https:\/\/www.dbi-services.com\/blog\/when-a-function-returns-a-collection-can-you-directly-reference-the-index-of-the-returned-collection\/"},"modified":"2015-06-20T12:56:42","modified_gmt":"2015-06-20T10:56:42","slug":"when-a-function-returns-a-collection-can-you-directly-reference-the-index-of-the-returned-collection","status":"publish","type":"post","link":"https:\/\/www.dbi-services.com\/blog\/when-a-function-returns-a-collection-can-you-directly-reference-the-index-of-the-returned-collection\/","title":{"rendered":"When a function returns a collection: can you directly reference the index of the returned collection?"},"content":{"rendered":"

As I am still interested in PLSQL I browsed the documentation<\/a> some days ago and learned something new which is about functions returning collections. Here is a simple test case:
\n\"Read
\nLet’s create a simple package, specifying on collection and one function:<\/p>\n

create or replace package pkg1 as\n  type t1 is table of number index by pls_integer;\n  function f1 ( a number ) return t1;\nend pkg1;\n\/\n\ncreate or replace package body pkg1\nas\n  function f1 ( a number ) return t1\n  is\n   lt1 t1;\n  begin\n    lt1(1) := 1;\n    lt1(2) := 2;\n    lt1(3) := 3;\n    return lt1;\n  end f1;\nbegin\n  null;\nend;\n\/\n<\/pre>\n
If I call the f1 function which returns a collection: Can I directly reference the collection returned by index?<\/p>\n
SQL> !cat exec_test_func.sql\nset serverout on\ndeclare\n  lt1 pkg1.t1;\n  ln number;\nbegin\n  ln := pkg1.f1(10)(3); \n  dbms_output.put_line(ln);\nend;\n\/\n<\/pre>\n
Yes, I really can. This might not seems very useful at the very first moment. But imagine there is a function which returns a collection indexed by varchar2. Then I could directly reference the collection by an index I might me interested in:<\/p>\n
create or replace package pkg2 as\n  type t1 is table of number index by varchar2(6);\n  function f1 ( a number ) return t1;\nend pkg2;\n\/\n\ncreate or replace package body pkg2\nas\n  function f1 ( a number ) return t1\n  is\n   lt1 t1;\n  begin\n    lt1('FIRST') := 1;\n    lt1('SECOND') := 2;\n    lt1('THIRD') := 3;\n    return lt1;\n  end f1;\nbegin\n  null;\nend pkg2;\n\/\n<\/pre>\n
Let’s directly reference an index of the returned collection:<\/p>\n
SQL> !cat exec_test_func.sql\nset serverout on\ndeclare\n  lt1 pkg2.t1;\n  ln number;\nbegin\n  ln := pkg2.f1(10)('SECOND'); \n  dbms_output.put_line(ln);\nend;\n\/\n<\/pre>\n
Might be useful for some situations …<\/p>\n","protected":false},"excerpt":{"rendered":"
As I am still interested in PLSQL I browsed the documentation some days ago and learned something new which is about functions returning collections. Here is a simple test case: Let’s create a simple package, specifying on collection and one function: create or replace package pkg1 as type t1 is table of number index by […]<\/p>\n","protected":false},"author":29,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[229],"tags":[96,24],"type_dbi":[],"class_list":["post-5171","post","type-post","status-publish","format-standard","hentry","category-database-administration-monitoring","tag-oracle","tag-pl-sql"],"acf":[],"yoast_head":"\nWhen a function returns a collection: can you directly reference the index of the returned collection? - dbi Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.dbi-services.com\/blog\/when-a-function-returns-a-collection-can-you-directly-reference-the-index-of-the-returned-collection\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"When a function returns a collection: can you directly reference the index of the returned collection?\" \/>\n<meta property=\"og:description\" content=\"As I am still interested in PLSQL I browsed the documentation some days ago and learned something new which is about functions returning collections. 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