Question

警告：我已经知道，这真是令人费解和可怕。但是，我没有构建数据库，我只需要使用它，我无法更改数据库架构。

以下是我正在使用的表格：

射击

ShotID（身份），FilmID（FK），ShotNumber，....，。

代码

TagID（身份），姓名

TaggedShot

TaggedShotID（身份），ShotID（FK），TagID（FK），TagComment

TaggedCategory

TagID（FK），CategoryID（FK）

我的存储过程：

    [dbo].[SelectAllTagNames]
        @filmID int,
        @tagCategory int
    AS
        DECLARE @i int
        DECLARE @numRows int
        DECLARE @ShotID int
        DECLARE @TagID int
        DECLARE @TagName nvarchar(50)
        DECLARE @shot_table TABLE(
        idx smallint Primary Key IDENTITY(1,1),
        ShotID int )
        DECLARE @tagID_table TABLE(
        idTag smallint Primary Key IDENTITY(1,1),
        TagID int)
        DECLARE @tagname_table TABLE(
        idTagName smallint Primary Key IDENTITY(1,1),
        TagName nvarchar(50))

//get all shots in the film
        INSERT @shot_table
        SELECT Shot.ShotID
        FROM Shot
        WHERE Shot.FilmID = @filmID

    //enumerate through shot table and build a tagID table of all TagIDs associated with any shot found in the shot_table
        SET @i = 1
        SET @numRows = (SELECT COUNT(*) FROM @shot_table)
        IF @numRows > 0
        BEGIN
            WHILE (@i <= (SELECT MAX(idx) FROM @shot_table))
            BEGIN

            SET @ShotID = (SELECT ShotID FROM @shot_table WHERE idx = @i)
            SET @TagID = (SELECT TaggedShot.TagID FROM TaggedShot WHERE TaggedShot.ShotID = @ShotID)

            INSERT INTO @tagID_table(TagID)
            VALUES(@TagID)

            SET @i = @i + 1

            END
        END
    //compare each TagID found in tagID_table with the TagID in the TaggedCategory table
// insert Tag.Name into new table if the Tag.TagID matches the TagID in the tagID_table and also matches the given tagCategory
        SET @i = 1
        SET @numRows = (SELECT COUNT(*) FROM @tagID_table)
        IF @numRows > 0
            WHILE (@i <= (SELECT MAX(idTag) FROM @tagID_table))
                BEGIN
                SET @TagID = (SELECT TagID FROM @tagID_table WHERE idTag = @i)
                IF EXISTS(SELECT TaggedCategory.TagId FROM TaggedCategory WHERE TaggedCategory.CategoryID = @tagCategory)
                    BEGIN

                    SET @TagName = (SELECT Tag.Name FROM Tag WHERE Tag.TagId = @TagID)

                    INSERT INTO @tagname_table(TagName)
                    VALUES(@TagName)

                    END
                END
    //return all the found tag names
    SELECT TagName
    FROM @tagname_table

这是我想要实现的目标：鉴于FilmID和标签类别ID（它只是1,2或3的整数 - 我在代码隐藏中确定了这一点），我需要找到给定这两个标准的所有Tag.Names。电影由镜头组成。

Answer 1

这未经过测试，但您无法通过所提供的表格的简单连接来处理您要实现的目标。如下所示：

 SELECT DISTINCT t.NAME
 FROM Shot s
 INNER JOIN TaggedShot ts ON s.ShotId = ts.ShotId
 INNER JOIN Tag t ON ts.TagId = t.TagId
 INNER JOIN TaggedCategory tc ON t.TagId = tc.TagId
 WHERE s.FilmId = @filmId
     AND tc.Categoryid = @tagCategory

根据以下评论进行更新：

 SELECT t.TagId
        ,t.Name
 FROM Tag t
 WHERE t.TagId IN (
      SELECT DISTINCT t.TagId
      FROM Shot s
      INNER JOIN TaggedShot ts ON s.ShotId = ts.ShotId
      INNER JOIN Tag t ON ts.TagId = t.TagId
      INNER JOIN TaggedCategory tc ON t.TagId = tc.TagId
      WHERE s.FilmId = @filmId
          AND tc.Categoryid = @tagCategory)

MSSQL存储过程 - 通过比较不同表中的值来选择列

1 个答案: