Question

我的功能有点问题。我收到一个语法错误，我不知道如何一次性插入多个内容。

基本上我希望 safe_insert() 函数接受：

_museum_id id 表中的 museums
_curr_date 一个日期字符串，例如。 2021-01-23 09:23:48
_customers 以逗号分隔的字符串，例如。 bob, billy,zoey,sarah,heather

但是，当它插入组成员时，它应该在 group_members 中插入 5 行，因为在这种情况下有 5 个名称（bob,billy,zoey,sarah,heather）。

错误/问题：

一个我不知道如何修复的语法错误#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '' at line 9
我也不知道如何用逗号分隔字符串以插入 5 行。

表格：

DROP TABLE IF EXISTS group_members;
DROP TABLE IF EXISTS group_visit;
DROP TABLE IF EXISTS museums;
CREATE TABLE museums (

    id                          int
                                NOT NULL
                                AUTO_INCREMENT
                                PRIMARY KEY,
    
    name                        varchar(64)
                                not null
);

INSERT INTO museums (id, name) VALUES (1, 'dino-museums');

CREATE TABLE group_visit (

    id                          int
                                NOT NULL
                                AUTO_INCREMENT
                                PRIMARY KEY,

    museum_id                   int
                                NOT NULL,
                                FOREIGN KEY (museum_id) REFERENCES museums (id),

    date_added                  datetime
                                NOT NULL
);

CREATE TABLE group_members (

    group_visit_id              int
                                NOT NULL,
                                FOREIGN KEY (group_visit_id) REFERENCES group_visit (id),

    customer                    varchar(32)
                                NOT NULL,

    PRIMARY KEY (group_visit_id, customer)
);

我的功能：

DROP FUNCTION IF EXISTS safe_insert;
    
DELIMITER //
CREATE FUNCTION safe_insert(
    _museum_id INT,
    _curr_date VARCHAR(32),
    _customers varchar(1024)
    ) RETURNS int
   
BEGIN
  DECLARE
    should_insert_museum int DEFAULT 1;
    group_visit_id int;
    
    
    /* Check if a group visit with the same museum_id has been inserted in the last 15 minutes */
    SELECT 0 INTO should_insert_museum
    FROM group_visit
    WHERE museum_id = _museum_id
    AND date_added >= DATE_SUB(_curr_date INTERVAL 15 MINUTE);
    
    /* If we found a result, do not insert anything and return 0 */
    IF should_insert_museum = 0 THEN
        RETURN should_insert_museum;
    
    /* Insert a group visit and store the id in group_Visit_id */
    INSERT INTO group_visit (museum_id, date_added) VALUES (_museum_id, _curr_date);
    SELECT LAST_INSERT_ID() INTO group_visit_id;
    
    /* How do I insert the list of customers into group_members */
    
        
  
  RETURN group_visit_id;
  
  
END //
DELIMITER ;

Answer 1

我并不是认真地提倡将其作为解决方案，因为我认为应该在应用程序代码中处理这样的事情，但只是为了好玩...

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如何根据条件创建插入函数

1 个答案: