0

我是一个开始自学 SQL/T-SQL 的新手。我一直在使用 SQL 2014 Express 并尝试通过编写 T-SQL 脚本来完成所有工作。我这样做是为了帮助一位朋友为她正在编写的真人游戏建立一个数据库，并且可以使用一些帮助来使以下用户定义的功能更加精简/以更正确的方式编写它。

我认为该函数本身是必要的，因为需要持续计算来确定物品的经济价值。这似乎比尝试执行某种更新脚本（每次更新 Items 表时更新所有值）更好的方法。抱歉，如果这一切看起来很简陋，请尝试学习。

下面是代码。我让它工作，我在我的开发数据库中得到它，它做了它应该做的事情。但我想清理它，我不知道该怎么做。

    CREATE FUNCTION dbo.ValueCalc (@itemid int)
    RETURNS INT
    AS
    BEGIN
    declare @rm1 int, @rm1amount int, @rm1value int,
    @rm2 int, @rm2amount int, @rm2value int,
    @rm3 int, @rm3amount int, @rm3value int,
    @rm4 int, @rm4amount int, @rm4value int,
    @cm1 int, @cm1amount int, @cm1value int,
    @cm2 int, @cm2amount int, @cm2value int,
    @cm3 int, @cm3amount int, @cm3value int,
    @cm4 int, @cm4amount int, @cm4value int,
    @productionvalue int;

    select @rm1 = MatReqs.RM1 FROM MatReqs WHERE MatReqs.ItemId = @itemid; 
    select @rm1amount = MatReqs.RM1Amount FROM MatReqs WHERE MatReqs.ItemId = @itemid; 
    select @rm1value = RawMats.BaseValue FROM RawMats WHERE RawMats.RawMatId = @rm1; 
    if (@rm1 IS NULL) set @rm1=0;
    if (@rm1amount IS NULL) set @rm1amount=0;
    if (@rm1value IS NULL) set @rm1value=0;

    {Repeat the above 3 more times, for rm2, rm3, and rm4}

    select @cm1 = MatReqs.CM1 FROM MatReqs WHERE MatReqs.ItemId = @itemid;
    select @cm1amount = MatReqs.CM1Amount FROM MatReqs WHERE MatReqs.ItemId = @itemid;
    select @cm1value = Items.ProdValue FROM Items WHERE Items.ItemId = @cm1;
    if (@cm1 IS NULL) set @cm1=0;
    if (@cm1amount IS NULL) set @cm1amount=0;
    if (@cm1value IS NULL) set @cm1value=0;

    {same here, just removed the repetitions}      

    set @productionvalue = (@rm1amount * @rm1value) 
    + (@rm2amount * @rm2value) 
    + (@rm3amount*@rm3value) 
    + (@rm4amount*@rm4value)
    + (@cm1amount*@cm1value)
    + (@cm2amount*@cm2value)
    + (@cm3amount*@cm3value)
    + (@cm4amount*@cm4value);

    set @productionvalue = @productionvalue + (@productionvalue * .15);

    return @productionvalue;
    END
    GO
4

1 回答 1

0

如果我有一些示例数据和您想要的结果以及您的整个函数，我可以编写一个更有效的解决方案，因为 SQL Server 针对基于集合的代码进行了优化，而您并没有真正使用它。至于简单的清理，你可以这样做，但我宁愿你发布什么样本数据和期望的结果，让我给你一个很好的基于集合的解决方案。

CREATE FUNCTION dbo.ValueCalc (@itemid INT)
RETURNS INT
AS
BEGIN
DECLARE @rm1 INT, @rm1amount INT, @rm1value INT,
        @rm2 INT, @rm2amount INT, @rm2value INT,
        @rm3 INT, @rm3amount INT, @rm3value INT,
        @rm4 INT, @rm4amount INT, @rm4value INT,
        @cm1 INT, @cm1amount INT, @cm1value INT,
        @cm2 INT, @cm2amount INT, @cm2value INT,
        @cm3 INT, @cm3amount INT, @cm3value INT,
        @cm4 INT, @cm4amount INT, @cm4value INT,
        @productionvalue INT;

--They both come from the same table with the where clause so just combine them
SELECT  @rm1 = ISNULL(MatReqs.RM1,0), 
        @rm1amount = ISNULL(MatReqs.RM1Amount,0)    
FROM MatReqs 
WHERE MatReqs.ItemId = @itemid; 

SELECT @rm1value = ISNULL(RawMats.BaseValue,0)  F
FROM RawMats 
WHERE RawMats.RawMatId = @rm1; 

--The ISNULL() function will take care of this
    --if (@rm1 IS NULL) set @rm1=0;
    --if (@rm1amount IS NULL) set @rm1amount=0;
    --if (@rm1value IS NULL) set @rm1value=0;


--Combine the first two statements again
SELECT  @cm1 = ISNULL(MatReqs.CM1,0),
        @cm1amount = ISNULL(MatReqs.CM1Amount,0)
FROM MatReqs 
WHERE MatReqs.ItemId = @itemid;

SELECT @cm1value = ISNULL(Items.ProdValue,0)
FROM Items 
WHERE Items.ItemId = @cm1;

--Again just use ISNULL
    --if (@cm1 IS NULL) set @cm1=0;
    --if (@cm1amount IS NULL) set @cm1amount=0;
    --if (@cm1value IS NULL) set @cm1value=0;
于 2015-03-26T05:38:20.873 回答