如何查找VARRAY中是否存在值

Question

我在表中创建VARRAY（下） 我想查询标题是否具有特定的主题，例如。显示“行动”游戏。 我不知道如何去这个...

CREATE OR REPLACE TYPE Theme_Game AS OBJECT 
(Theme VARCHAR(20)); 
/
CREATE OR REPLACE TYPE Theme_Type AS VARRAY(3) OF Theme_Game; 
/
CREATE OR REPLACE TYPE Game_Type AS OBJECT 
(Title VARCHAR2(50), 
GameTheme Theme_Type); 
/
CREATE TABLE Game_Table of Game_Type 
/
INSERT INTO Game_Table 
VALUES('Star Wars' ,(Theme_Type(Theme_Game('Action'), Theme_Game('FPS')))) 
/

Answer 1

您需要使用table()功能揭露嵌套表在FROM子句中。然后，您可以参考集合的属性：

SQL> select g.title 
    2 from game_table g 
    3  , table(g.gametheme) gt 
    4 where gt.theme = 'Action'; 

TITLE 
-------------------------------------------------- 
Star Wars 

SQL> 

---

“如果我再需要检索与多个主题即动作，FPS行？”

抱歉，笨重的解决方案，但我需要现在去工作。我稍后可能会发布更优雅的解决方案。

SQL> select * from game_table 
    2/

TITLE 
-------------------------------------------------- 
GAMETHEME(THEME) 
-------------------------------------------------------------------------------- 
Star Wars 
THEME_TYPE(THEME_GAME('Action'), THEME_GAME('FPS')) 

Uncharted 3 
THEME_TYPE(THEME_GAME('Action'), THEME_GAME('Puzzle')) 

Commander Cody 
THEME_TYPE(THEME_GAME('Fun'), THEME_GAME('Puzzle')) 


SQL> select g.title 
    2 from game_table g 
    3  , table(g.gametheme) gt 
    4  , table(g.gametheme) gt1 
    5 where gt.theme = 'Action' 
    6 and gt1.theme = 'FPS' ; 

TITLE 
-------------------------------------------------- 
Star Wars 

SQL> 

---

这种替代方法不会与您的当前类型的工作，因为VARRAY不支持member of。但是如果这个集合是一个嵌套表，它将会工作。

select g.title 
    from game_table g 
    where 'Action' member of g.gametheme 
    and 'FPS' member of g.gametheme 

Answer 2

对于多个主题，您可以做类似

select g.Title 
from game_table g, table(g.gameTheme) t 
where t.Theme in ('FPS','Action') 
group by g.Title having count(0) = 2; 

这也可以让你做的事情一样获得技术职称正好n个匹配，至少n个匹配，最多n相匹配......

Answer 3

你可以使用一个集合，然后比较使用SUBMULTISET操作多个项目：

SQL Fiddle

的Oracle 11g R2架构设置：

CREATE OR REPLACE TYPE Theme_Game AS OBJECT 
(Theme VARCHAR(20)); 
/
CREATE OR REPLACE TYPE Theme_Type AS TABLE OF Theme_Game; 
/
CREATE OR REPLACE TYPE Game_Type AS OBJECT(
    Title VARCHAR2(50), 
    GameTheme Theme_Type 
); 
/
CREATE TABLE Game_Table of Game_Type 
NESTED TABLE GameTheme STORE AS GameTheme_Tab 
/
INSERT INTO Game_Table 
VALUES('Star Wars' ,(Theme_Type(Theme_Game('Action'), Theme_Game('FPS')))) 
/

查询1：

SELECT * 
FROM game_table 
WHERE Theme_Type(Theme_Game('Action'), Theme_Game('FPS')) 
     SUBMULTISET OF GameTheme 

Results：

|  TITLE |            GAMETHEME | 
|-----------|-------------------------------------------------------| 
| Star Wars | oracle.sql.STRUCT@67e8dc0f,oracle.sql.STRUCT@795b6d4c | 

然而，为什么为Y ou使用Theme_Game对象时，它只有一个VARCHAR2属性？你可以只使用一个VARRAY(3) OF VARCHAR2(20)或TABLE OF VARCHAR2(20)没有中间对象：

SQL Fiddle

的Oracle 11g R2架构设置：

CREATE OR REPLACE TYPE Varchar20List AS TABLE OF VARCHAR2(20); 
/
CREATE OR REPLACE TYPE Game_Type AS OBJECT(
    Title VARCHAR2(50), 
    GameTheme Varchar20List 
); 
/
CREATE TABLE Game_Table of Game_Type 
NESTED TABLE GameTheme STORE AS GameTheme_Tab 
/
INSERT INTO Game_Table 
VALUES('Star Wars' , Varchar20List('Action', 'FPS')) 
/

查询1：

SELECT * 
FROM game_table 
WHERE Varchar20List('Action','FPS') 
     SUBMULTISET OF GameTheme 

Results：

|  TITLE | GAMETHEME | 
|-----------|------------| 
| Star Wars | Action,FPS | 

如果你想与VARRAY s到做到这一点，那么：

SQL Fiddle

的Oracle 11g R2架构设置：

CREATE OR REPLACE TYPE Varchar20List AS VARRAY(3) OF VARCHAR2(20); 
/
CREATE OR REPLACE TYPE Game_Type AS OBJECT(
    Title VARCHAR2(50), 
    GameTheme Varchar20List 
); 
/
CREATE TABLE Game_Table of Game_Type 
/
INSERT INTO Game_Table 
VALUES('Star Wars' , Varchar20List('Action', 'FPS')) 
/

查询1 ：

SELECT * 
FROM game_table g 
WHERE 2 >= (SELECT COUNT(*) 
       FROM TABLE(g.GameTheme) a 
        INNER JOIN 
        TABLE(Varchar20List('Action', 'FPS')) b 
        ON (a.COLUMN_VALUE = b.COLUMN_VALUE) 
      ) 

Results：

|  TITLE | GAMETHEME | 
|-----------|------------| 
| Star Wars | Action,FPS | 

或：

查询2：

SELECT * 
FROM game_table g 
WHERE 2 >= (SELECT COUNT(*) 
       FROM TABLE(g.GameTheme) a 
       WHERE a.COLUMN_VALUE IN ('Action', 'FPS') 
      ) 

Results ：

|  TITLE | GAMETHEME | 
|-----------|------------| 
| Star Wars | Action,FPS |