Sql 正确使用Postgres JSON转换函数

我正在处理Postgres更新事务

假设我有两个表：

events

和

ticket\u books

，其中包含事件预订类型。ticket\u books表有一个外键，指向

事件

我需要更新存储在数据库中的事件，包括

ticket\u books

表中的预订类型记录

为了处理级联更新和删除，我决定在“伪代码”中构建一个事务，它看起来像：

    BEGIN;
      DELETE FROM
        ticket_books
      WHERE
        event_id = ${req.params.id} AND
        id NOT IN (${bookingIds})
      FOR booking IN json_to_recordset('${JSON.stringify(book)}') as book(id int, title varchar(200), price int, ...) LOOP
        IF bookind.id THEN
          UPDATE
            ticket_books
          SET
            title = booking.title, price = booking.price
          WHERE
            event_id = ${req.params.id};
        ELSE
          INSERT INTO
            ticket_books (title, price, qty_available, qty_per_sale)
          VALUES
            (booking.title, booking.price, booking.qty_available, booking.qty_per_sale)
          RETURNING
            id
        END IF;
      END LOOP;
   UPDATE
     event
   SET
    ...
   WHERE
     id = ...
   RETURNING
     id;
   COMMIT;

FOR booking IN json_to_record('[{"id":13,"description":"Three day access to the festival","title":"Three Day General Admission","price":260,"qty_available":5000,"qty_per_sale":10},{"id":14,"description":"Single day access to the festival","title":"Single Day General Admission","price":"90.90","qty_available":2000,"qty_per_sale":2},{"title":"Free Admission","price":"0.00","qty_available":0,"qty_per_sale":0}]')

我当前收到错误：

语法错误位于或接近“json\u to\u记录集”

。我以前从未使用过

json\u to\u记录集

或friends，只是从文档中看到了9.3和更高版本的可用性。不过，我不知道如何让博士后理解我的需求

我正在嵌入一个JSON数组，因此最后一行如下所示：

    BEGIN;
      DELETE FROM
        ticket_books
      WHERE
        event_id = ${req.params.id} AND
        id NOT IN (${bookingIds})
      FOR booking IN json_to_recordset('${JSON.stringify(book)}') as book(id int, title varchar(200), price int, ...) LOOP
        IF bookind.id THEN
          UPDATE
            ticket_books
          SET
            title = booking.title, price = booking.price
          WHERE
            event_id = ${req.params.id};
        ELSE
          INSERT INTO
            ticket_books (title, price, qty_available, qty_per_sale)
          VALUES
            (booking.title, booking.price, booking.qty_available, booking.qty_per_sale)
          RETURNING
            id
        END IF;
      END LOOP;
   UPDATE
     event
   SET
    ...
   WHERE
     id = ...
   RETURNING
     id;
   COMMIT;

FOR booking IN json_to_record('[{"id":13,"description":"Three day access to the festival","title":"Three Day General Admission","price":260,"qty_available":5000,"qty_per_sale":10},{"id":14,"description":"Single day access to the festival","title":"Single Day General Admission","price":"90.90","qty_available":2000,"qty_per_sale":2},{"title":"Free Admission","price":"0.00","qty_available":0,"qty_per_sale":0}]')

---

我相信我的JSON数组是有效的。显然，我不应该这样把它传给博士后。我该怎么做呢？我的目标是迭代数组条目。如果booking.id有一个整数值，我想更新记录，否则插入一个新记录。

您需要一个查询，独立函数调用通常不算作查询：

FOR booking IN select * from json_to_recordset(...

此外，您不能在plpgsql中使用BEGIN启动事务。它仅用于启动块。如果您使用的是过程而不是函数，则可以提交，但新事务会立即启动，而不使用BEGIN令牌

您还缺少DELETE和FOR之间的分号，但是错误消息中似乎只缺少您的帖子，而实际代码中没有