Question

这是一个SQL视图，显示与ID为“2”的书籍在同一个书架中的书籍数量。是否有一种简单的方法可以将其转换为可以输入书籍ID的过程，而不是默认情况下ID为“2”的过程？我还没有尝试过程序，这个特殊的程序是否涉及很多编码？

    SELECT COUNT(*) FROM books
    WHERE shelf_id = (SELECT shelf_id FROM books WHERE book_id = 2)

子查询是因为Book表有一个货架ID，但货架上没有书ID。

Answer 1

您的代码可能如下所示： -

CREATE PROCEDURE spBooks(@BookID integer)
AS
SELECT COUNT(*) FROM books
    WHERE shelf_id = (SELECT shelf_id FROM books WHERE book_id = @BookID)
GO;

那应该创建你想要的存储过程。

Answer 2

如果是甲骨文，请尝试以下内容：

    PROCEDURE GET_BOOK_COUNT(
        i_book_id            IN  books.book_id%TYPE,
        o_count              OUT NUMBER)
      AS
      BEGIN
            SELECT COUNT(*) INTO o_count  FROM books
            WHERE shelf_id = 
                         (SELECT shelf_id FROM books WHERE book_id = i_book_id );
      END GET_BOOK_COUNT;

但最好将其设为function而不是procedure：

      FUNCTION GET_BOOK_COUNT(
        i_book_id            IN  books.book_id%TYPE)
            RETURN NUMBER
            IS
            l_count Number;
            SELECT COUNT(*) INTO l_count  FROM books
            WHERE shelf_id = 
                         (SELECT shelf_id FROM books WHERE book_id = i_book_id );
            RETURN l_count;
      END GET_BOOK_COUNT;

SQL从视图中创建过程

2 个答案: