"存儲過程\/函數可以返回表嗎？"

Question

MySql 存儲過程\/函數可以在不使用臨時表的情況下返回一個表嗎？

創建以下過程

CREATE PROCEDURE database.getExamples() 
    SELECT * FROM examples;

Answer 1

就目前而言，這是不可能的。

以下是有關FROM<\/code>子句中可能使用的內容的文檔<\/strong><\/a>：

table_references:
    table_reference [, table_reference] ...

table_reference:
    table_factor
  | join_table

table_factor:
    tbl_name [[AS] alias] [index_hint)]
  | table_subquery [AS] alias
  | ( table_references )
  | { OJ table_reference LEFT OUTER JOIN table_reference
        ON conditional_expr }

join_table:
    table_reference [INNER | CROSS] JOIN table_factor [join_condition]
  | table_reference STRAIGHT_JOIN table_factor
  | table_reference STRAIGHT_JOIN table_factor ON conditional_expr
  | table_reference {LEFT|RIGHT} [OUTER] JOIN table_reference join_condition
  | table_reference NATURAL [{LEFT|RIGHT} [OUTER]] JOIN table_factor

join_condition:
    ON conditional_expr
  | USING (column_list)

index_hint:
    USE {INDEX|KEY} [FOR JOIN] (index_list)
  | IGNORE {INDEX|KEY} [FOR JOIN] (index_list)
  | FORCE {INDEX|KEY} [FOR JOIN] (index_list)

index_list:
    index_name [, index_name] ...

Answer 2

根據A.4 MySQL 5.6 FAQ：存儲過程和函數<\/em><\/a>：

A.4.14：MySQL 5.6 存儲例程可以返回結果集嗎？<\/a><\/h3>

存儲過程可以，但存儲函數不能。

<\/blockquote>"

Answer 3

看起來可以做到，但是使用存儲過程的輸出變量。 http:\/\/www.sqlinfo.net\/mysql\/mysql_stored_procedure_SELECT.php<\/a>

-- 1. Create Procedure
DROP PROCEDURE IF EXISTS `sp_students_SELECT_byPK` 
GO

CREATE PROCEDURE sp_students_SELECT_byPK
(
    IN   p_student_id                    INT(11)       , 
    OUT  p_password                      VARCHAR(15)   , 
    OUT  p_active_flg                    TINYINT(4)    , 
    OUT  p_lastname                      VARCHAR(30)   , 
    OUT  p_firstname                     VARCHAR(20)   , 
    OUT  p_gender_code                   VARCHAR(1)    , 
    OUT  p_birth_dttm                    DATETIME      
 )
BEGIN 

SELECT password                      , 
       active_flg                    , 
       lastname                      , 
       firstname                     , 
       gender_code                   , 
       birth_dttm                    
INTO   p_password                      , 
       p_active_flg                    , 
       p_lastname                      , 
       p_firstname                     , 
       p_gender_code                   , 
       p_birth_dttm                    
FROM   students
WHERE  student_id = p_student_id ; 

END 

GO

-- 2. Select Results from Stored Procedure
/***
IN    p_student_id   INT(11)
OUT   p_password     VARCHAR(15)
OUT   p_active_flg   TINYINT(4)
OUT   p_lastname     VARCHAR(30)
OUT   p_firstname    VARCHAR(20)
OUT   p_gender_code  VARCHAR(1)
OUT   p_birth_dttm   DATETIME
***/

CALL sp_students_SELECT_byPK
(
  8, 
  @p_password , 
  @p_active_flg , 
  @p_lastname , 
  @p_firstname , 
  @p_gender_code , 
  @p_birth_dttm
)
GO

SELECT @p_password      AS p_password      , 
   @p_active_flg    AS p_active_flg    , 
   @p_lastname      AS p_lastname      , 
   @p_firstname     AS p_firstname     , 
   @p_gender_code   AS p_gender_code   , 
   @p_birth_dttm    AS p_birth_dttm   
GO

Answer 4

每個不插入表或變量的 SELECT 語句都會產生一個結果集。

如果您希望您的存儲過程只返回一個結果集，請確保您只有一個 SELECT 語句。 如果您有其他 SELECT 語句，請確保它們將結果插入到表或變量中。

更新 這里是存儲過程的例子。

此存儲過程將返回一個結果集：

DELIMITER ;;
CREATE DEFINER=CURRENT_USER PROCEDURE stored_procedure_name()
BEGIN
    DECLARE local_variable_name INT;

    SELECT column_name FROM table_1 LIMIT 1 INTO local_variable_name;

    SELECT * FROM table_1;
END;;
DELIMITER ;
This stored procedure would return two result sets:

DELIMITER ;;
CREATE DEFINER=CURRENT_USER PROCEDURE stored_procedure_name()
BEGIN
    DECLARE local_variable_name INT;

    SELECT column_name FROM table_1 LIMIT 1 INTO local_variable_name;

    SELECT * FROM table_1;

    SELECT * FROM table_2;
END;;
DELIMITER ;

Answer 5

您可以通過使用視圖而不是存儲過程來完成您正在嘗試的事情，但這完全取決於存儲過程的作用。

如果使用臨時表是您唯一的選擇，請考慮使用 MEMORY 存儲引擎。