Oracle sql区分大小写索引

Question

在我的项目数据库中显示产品表，其中一列名为＆＃39; Name＆＃39; 因此，此表格可以包含＆＃39;产品A＆＃39;和＆＃39;产品a＆＃39; 应该在简单的选择查询中选择这两种产品。

我创建了索引： CREATE INDEX IDX_PRODUCT_NAME ON PRODUCTS(NAME)

然后运行SQL查询： SELECT /*+ INDEX(PRODUCTS IDX_PRODUCT_NAME)*/ * FROM PRODUCTS WHERE NAME='Product_a'

我做错了什么？

P.S。我知道有关更改会话标志的变体： NLS_COMP=ANSI; NLS_SORT=BINARY_CI; 但对于我有趣的变体没有更改数据库设置，它可能吗？或者例如仅为我的查询更改此标志。

请看一下图片

更新 William Robertson 帮我评论。 CREATE INDEX IDX_PRODUCT_NAME ON PRODUCTS(UPPER(NAME))

之后运行查询： SELECT * FROM PRODUCTS WHERE **UPPER**(NAME)='PRODUCT_A' 这个变种工作正常！

Answer 1

一种方法是添加虚拟列：

create table demo_products
( id          integer not null
, name        varchar2(20)
, name_upper  generated always as (upper(name)) );

create index demo_prod_upper_name_ix on demo_products(name_upper);

insert all
    into demo_products (id, name) values (1, 'Prod A')
    into demo_products (id, name) values (2, 'Prod a')
    into demo_products (id, name) values (3, 'Prod B')
    into demo_products (id, name) values (4, 'Prod b')
    into demo_products (id, name) values (5, 'prod A')
    into demo_products (id, name) values (6, 'Cheese')
    into demo_products (id, name) values (7, 'Bananas')
select * from dual;

commit;

select count(*) from demo_products where name_upper = 'PROD A';

  COUNT(*)
----------
         3

Plan hash value: 4158816492

---------------------------------------------------------------------------------------------
| Id  | Operation         | Name                    | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |                         |     1 |    12 |     1   (0)| 00:00:01 |
|   1 |  SORT AGGREGATE   |                         |     1 |    12 |            |          |
|*  2 |   INDEX RANGE SCAN| DEMO_PROD_UPPER_NAME_IX |     1 |    12 |     1   (0)| 00:00:01 |
---------------------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------
   2 - access("NAME_UPPER"='PROD A')