SQL 未按预期工作答案

【问题标题】：SQL isn't working as intendedSQL 未按预期工作
【发布时间】：2015-09-16 12:03:06
【问题描述】：

我在尝试运行的SQL 查询中有一个问题（此时我正在练习）。我正在尝试在 2 个特定日期和一些条件之间获取一些注册表。

问题是，查询无法正常工作，因为它始终只显示相同的注册表，我的意思是，如果有 100 条目，则查询显示 100 次相同的条目。

这是查询：

SELECT Base.Registry.Registry,
       Base.Client.Name,
       Base.Client.Surname1,
       Base.Client.Surname2,
       Base.Client.BirthDate,
       Base.Registry.Edad,
       Base.Client.NIF,
       Base.Registry.Procedency,
       Base.Registry.DateRegistry,
       Base.Registry.DateValidation,
       Base.Registry.CodeSample,
       Base.SnomedRegistry.Code,
       Base.Sample.T
FROM Base.Registry,
     Base.Client,
     Base.SnomedRegistry,
     Base.Sample
WHERE Base.Registry.CodeClient = Base.Client.CodeClient
  AND Base.Registry.Registry = Base.SnomedRegistry.Registry
  AND Base.Registry.CodeSample = Base.Sample.Sample
  AND Base.Registry.DateRegistry BETWEEN '2012-10-26' AND '2012-12-31'
  AND Base.SnomedRegistry.Code LIKE 'M8%%%3'
  OR Base.SnomedRegistry.Code LIKE 'M8%%%2'
  OR Base.SnomedRegistry.Code LIKE 'M8%%%6'
  OR Base.SnomedRegistry.Code LIKE 'M8%%%9'
  OR Base.SnomedRegistry.Code LIKE 'M9%%%2'
  OR Base.SnomedRegistry.Code LIKE 'M9%%%3'
  OR Base.SnomedRegistry.Code LIKE 'M9%%%6'
  OR Base.SnomedRegistry.Code LIKE 'M9%%%9'
  OR Base.SnomedRegistry.Code LIKE 'M69730'
  OR Base.SnomedRegistry.Code LIKE 'M60760'
  OR Base.SnomedRegistry.Code LIKE 'M74000'
  OR Base.SnomedRegistry.Code LIKE 'M74007'
  OR Base.SnomedRegistry.Code LIKE 'M74008'
  LIMIT 0, 100

我现在对 SQL 非常缺乏经验，所以每一个建议都将不胜感激。

Obs：对不起我的英语。

【问题讨论】：

你需要在where 中加上括号来获得你想要的逻辑。但是，您应该修复您的查询以使用正确的显式 join 语法。简单规则：从不在FROM 子句中使用逗号。
% 匹配任意数量的字符，甚至是零个字符，因此无需添加 M8%%%2 或使用 _ 匹配一个字符，如 M8___2跨度>

标签： mysql sql tsql

【解决方案1】：

我会发表评论而不是提供答案，但我需要 50 分才能做到这一点。哈哈

我不太清楚为什么你需要像 %%%%% 这样多次使用 %，因为通常一个 % 就足够了。

我会说您的问题与您的 from 语句有关，理想情况下需要使用连接。

我还会在您的like 语句周围使用方括号...

WHERE   1 = 1 
    AND Base.Registry.CodeClient = Base.Client.CodeClient
    AND Base.Registry.Registry = Base.SnomedRegistry.Registry
    AND Base.Registry.CodeSample = Base.Sample.Sample
    AND Base.Registry.DateRegistry BETWEEN '2012-10-26' AND '2012-12-31'
    AND (
            Base.SnomedRegistry.Code LIKE 'M8%3'
            OR Base.SnomedRegistry.Code LIKE 'M8%2'
            OR Base.SnomedRegistry.Code LIKE 'M8%6'
            OR Base.SnomedRegistry.Code LIKE 'M8%9'
            OR Base.SnomedRegistry.Code LIKE 'M9%2'
            OR Base.SnomedRegistry.Code LIKE 'M9%3'
            OR Base.SnomedRegistry.Code LIKE 'M9%6'
            OR Base.SnomedRegistry.Code LIKE 'M9%9'
            OR Base.SnomedRegistry.Code LIKE 'M69730'
            OR Base.SnomedRegistry.Code LIKE 'M60760'
            OR Base.SnomedRegistry.Code LIKE 'M74000'
            OR Base.SnomedRegistry.Code LIKE 'M74007'
            OR Base.SnomedRegistry.Code LIKE 'M74008'
        )
LIMIT 0 , 100

【讨论】：

【解决方案2】：

你忘了括号：

SELECT ...
FROM Base.Registry, Base.Client, Base.SnomedRegistry, Base.Sample
WHERE Base.Registry.CodeClient = Base.Client.CodeClient
AND Base.Registry.Registry = Base.SnomedRegistry.Registry
AND Base.Registry.CodeSample = Base.Sample.Sample
AND Base.Registry.DateRegistry
BETWEEN '2012-10-26' AND '2012-12-31'
AND (    #<----- here
   Base.SnomedRegistry.Code LIKE 'M8%%%3'
OR Base.SnomedRegistry.Code LIKE 'M8%%%2'
OR Base.SnomedRegistry.Code LIKE 'M8%%%6'
OR Base.SnomedRegistry.Code LIKE 'M8%%%9'
OR Base.SnomedRegistry.Code LIKE 'M9%%%2'
OR Base.SnomedRegistry.Code LIKE 'M9%%%3'
OR Base.SnomedRegistry.Code LIKE 'M9%%%6'
OR Base.SnomedRegistry.Code LIKE 'M9%%%9'
OR Base.SnomedRegistry.Code LIKE 'M69730'
OR Base.SnomedRegistry.Code LIKE 'M60760'
OR Base.SnomedRegistry.Code LIKE 'M74000'
OR Base.SnomedRegistry.Code LIKE 'M74007'
OR Base.SnomedRegistry.Code LIKE 'M74008' 
)   #<----- here
LIMIT 0 , 100

【讨论】：

【解决方案3】：

使用join 和括号：

SELECT Base.Registry.Registry, Base.Client.Name, Base.Client.Surname1, Base.Client.Surname2, Base.Client.BirthDate, Base.Registry.Edad, Base.Client.NIF, Base.Registry.Procedency, Base.Registry.DateRegistry, Base.Registry.DateValidation, Base.Registry.CodeSample, Base.SnomedRegistry.Code, Base.Sample.T
FROM Base.Registry
inner join Base.Client on Base.Registry.CodeClient = Base.Client.CodeClient
inner join Base.SnomedRegistry on Base.Registry.Registry = Base.SnomedRegistry.Registry
inner join Base.Sample on Base.Registry.CodeSample = Base.Sample.Sample
WHERE Base.Registry.DateRegistry BETWEEN '2012-10-26' AND '2012-12-31'
AND (Base.SnomedRegistry.Code LIKE 'M8%%%3'
OR Base.SnomedRegistry.Code LIKE 'M8%%%2'
OR Base.SnomedRegistry.Code LIKE 'M8%%%6'
OR Base.SnomedRegistry.Code LIKE 'M8%%%9'
OR Base.SnomedRegistry.Code LIKE 'M9%%%2'
OR Base.SnomedRegistry.Code LIKE 'M9%%%3'
OR Base.SnomedRegistry.Code LIKE 'M9%%%6'
OR Base.SnomedRegistry.Code LIKE 'M9%%%9'
OR Base.SnomedRegistry.Code LIKE 'M69730'
OR Base.SnomedRegistry.Code LIKE 'M60760'
OR Base.SnomedRegistry.Code LIKE 'M74000'
OR Base.SnomedRegistry.Code LIKE 'M74007'
OR Base.SnomedRegistry.Code LIKE 'M74008')
LIMIT 0 , 100

【讨论】：