Mysql SQL查询未返回条件集_Mysql_Sql_Criteria_Where

Mysql SQL查询未返回条件集

mysql sql

Mysql SQL查询未返回条件集,mysql,sql,criteria,where,Mysql,Sql,Criteria,Where,我正在开发一个花坛种植系统，并编写了一个SQL语句，查询8个表，以返回合适的植物列表表结构：[从phpmyadmin输出] 示例数据：/ SQL语句： SELECT Plant.Plant_ID, Plant.Plant_Quantity, Plant.Plant_Price, Plant.Plant_Description, Plant.Plant_Latin_Name, Plant.Plant_Common_Name, Plant.Plant_Height, Plant.Plant_Spr

我正在开发一个花坛种植系统，并编写了一个SQL语句，查询8个表，以返回合适的植物列表

表结构：[从phpmyadmin输出]

示例数据：/

SQL语句：

SELECT Plant.Plant_ID, Plant.Plant_Quantity, Plant.Plant_Price, Plant.Plant_Description, Plant.Plant_Latin_Name, Plant.Plant_Common_Name, Plant.Plant_Height, Plant.Plant_Spread, Plant.Plant_Type, Plant.Plant_Family, Plant.Plant_Picture, Plant_Aspect.Plant_Aspect, Plant_Flower_Colour.Plant_Flower_Colour, Plant_Flower_Colour.Plant_Season, Plant_Foliage_Colour.Plant_Foliage_Colour, Plant_Foliage_Colour.Plant_Season, Plant_Moisture.Plant_Moisture, Plant_Soil_PH.Plant_Soil_PH, Plant_Soil_Type.Plant_Soil_Type, Plant_Sun_Type.Plant_Sun_Type 

FROM Plant 

INNER JOIN Plant_Aspect ON Plant.Plant_ID = Plant_Aspect.Plant_ID 
INNER JOIN Plant_Flower_Colour ON Plant.Plant_ID = Plant_Flower_Colour.Plant_ID 
INNER JOIN Plant_Foliage_Colour ON Plant.Plant_ID = Plant_Foliage_Colour.Plant_ID 
INNER JOIN Plant_Moisture ON Plant.Plant_ID = Plant_Moisture.Plant_ID
INNER JOIN Plant_Soil_PH ON Plant.Plant_ID = Plant_Soil_PH.Plant_ID 
INNER JOIN Plant_Soil_Type ON Plant.Plant_ID = Plant_Soil_Type.Plant_ID 
INNER JOIN Plant_Sun_Type ON Plant.Plant_ID = Plant_Sun_Type.Plant_ID 

WHERE Plant_Aspect.Plant_Aspect = 'East-facing'
OR Plant_Aspect.Plant_Aspect = 'Any'
AND Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
OR Plant_Soil_Type.Plant_Soil_Type = 'Any'
AND Plant_Moisture.Plant_Moisture = 'Well-drained' 
OR Plant_Moisture.Plant_Moisture = 'Any'
AND Plant_Soil_PH.Plant_Soil_PH = 'Acid'
OR Plant_Soil_PH.Plant_Soil_PH = 'Any'
AND Plant_Foliage_Colour.Plant_Foliage_Colour = 'Green'
AND Plant_Foliage_Colour.Plant_Season = 'Winter'
OR Plant_Foliage_Colour.Plant_Season = 'Any'
AND Plant_Flower_Colour.Plant_Flower_Colour = 'Orange'
AND Plant_Flower_Colour.Plant_Season = 'Winter'
OR Plant_Flower_Colour.Plant_Season = 'Any'

GROUP BY Plant_ID;

我希望查询只返回那些具有与搜索条件匹配的记录的植物，即只返回那些可以在“冬季”或“任何”季节种植的植物，但它返回的是不应该是的植物

例如：-

Plant\u ID:1

在

Plant\u Flower\u color

表中仅包含一条记录-春季为深蓝色。为什么这张唱片被退回了？就好像后面的

和

s和

或

s被忽略了一样

任何帮助都将不胜感激

我认为您至少需要在您的或标准周围加上括号：

...
WHERE (Plant_Aspect.Plant_Aspect = 'East-facing'
OR Plant_Aspect.Plant_Aspect = 'Any')
AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
OR Plant_Soil_Type.Plant_Soil_Type = 'Any')
...

我认为至少你需要在你的或标准周围加上括号：

...
WHERE (Plant_Aspect.Plant_Aspect = 'East-facing'
OR Plant_Aspect.Plant_Aspect = 'Any')
AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
OR Plant_Soil_Type.Plant_Soil_Type = 'Any')
...

WHERE子句中的分组是错误的，对一般读者来说是不明确的。并且绑定比或更紧密，因此需要使用括号向DBMS说明您的意图：

WHERE (Plant_Aspect.Plant_Aspect = 'East-facing'
   OR  Plant_Aspect.Plant_Aspect = 'Any')
  AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
   OR  Plant_Soil_Type.Plant_Soil_Type = 'Any')
  AND (Plant_Moisture.Plant_Moisture = 'Well-drained' 
   OR  Plant_Moisture.Plant_Moisture = 'Any')
  AND (Plant_Soil_PH.Plant_Soil_PH = 'Acid'
   OR  Plant_Soil_PH.Plant_Soil_PH = 'Any')
  AND  Plant_Foliage_Colour.Plant_Foliage_Colour = 'Green'
  AND (Plant_Foliage_Colour.Plant_Season = 'Winter'
   OR  Plant_Foliage_Colour.Plant_Season = 'Any')
  AND  Plant_Flower_Colour.Plant_Flower_Colour = 'Orange'
  AND (Plant_Flower_Colour.Plant_Season = 'Winter'
   OR  Plant_Flower_Colour.Plant_Season = 'Any')

您所写的内容被视为您所写：

WHERE子句中的分组是错误的，对普通读者来说是不明确的。并且绑定比或更紧密，因此需要使用括号向DBMS说明您的意图：

WHERE (Plant_Aspect.Plant_Aspect = 'East-facing'
   OR  Plant_Aspect.Plant_Aspect = 'Any')
  AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
   OR  Plant_Soil_Type.Plant_Soil_Type = 'Any')
  AND (Plant_Moisture.Plant_Moisture = 'Well-drained' 
   OR  Plant_Moisture.Plant_Moisture = 'Any')
  AND (Plant_Soil_PH.Plant_Soil_PH = 'Acid'
   OR  Plant_Soil_PH.Plant_Soil_PH = 'Any')
  AND  Plant_Foliage_Colour.Plant_Foliage_Colour = 'Green'
  AND (Plant_Foliage_Colour.Plant_Season = 'Winter'
   OR  Plant_Foliage_Colour.Plant_Season = 'Any')
  AND  Plant_Flower_Colour.Plant_Flower_Colour = 'Orange'
  AND (Plant_Flower_Colour.Plant_Season = 'Winter'
   OR  Plant_Flower_Colour.Plant_Season = 'Any')

您所写的内容被视为您所写：

尝试将括号放在或比较的周围

WHERE (Plant_Aspect.Plant_Aspect = 'East-facing'
OR Plant_Aspect.Plant_Aspect = 'Any')
AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
OR Plant_Soil_Type.Plant_Soil_Type = 'Any')
AND (Plant_Moisture.Plant_Moisture = 'Well-drained' 
OR Plant_Moisture.Plant_Moisture = 'Any')
AND (Plant_Soil_PH.Plant_Soil_PH = 'Acid'
OR Plant_Soil_PH.Plant_Soil_PH = 'Any')
AND Plant_Foliage_Colour.Plant_Foliage_Colour = 'Green'
AND (Plant_Foliage_Colour.Plant_Season = 'Winter'
OR Plant_Foliage_Colour.Plant_Season = 'Any')
AND Plant_Flower_Colour.Plant_Flower_Colour = 'Orange'
AND (Plant_Flower_Colour.Plant_Season = 'Winter' OR Plant_Flower_Colour.Plant_Season = 'Any')

尝试将括号放在或比较的周围

WHERE (Plant_Aspect.Plant_Aspect = 'East-facing'
OR Plant_Aspect.Plant_Aspect = 'Any')
AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
OR Plant_Soil_Type.Plant_Soil_Type = 'Any')
AND (Plant_Moisture.Plant_Moisture = 'Well-drained' 
OR Plant_Moisture.Plant_Moisture = 'Any')
AND (Plant_Soil_PH.Plant_Soil_PH = 'Acid'
OR Plant_Soil_PH.Plant_Soil_PH = 'Any')
AND Plant_Foliage_Colour.Plant_Foliage_Colour = 'Green'
AND (Plant_Foliage_Colour.Plant_Season = 'Winter'
OR Plant_Foliage_Colour.Plant_Season = 'Any')
AND Plant_Flower_Colour.Plant_Flower_Colour = 'Orange'
AND (Plant_Flower_Colour.Plant_Season = 'Winter' OR Plant_Flower_Colour.Plant_Season = 'Any')

您需要使用括号对where条件进行分组

WHERE 
(Plant_Aspect.Plant_Aspect = 'East-facing'
OR Plant_Aspect.Plant_Aspect = 'Any')
AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
OR Plant_Soil_Type.Plant_Soil_Type = 'Any')...

您需要使用括号对where条件进行分组

WHERE 
(Plant_Aspect.Plant_Aspect = 'East-facing'
OR Plant_Aspect.Plant_Aspect = 'Any')
AND (Plant_Soil_Type.Plant_Soil_Type = 'Sand' 
OR Plant_Soil_Type.Plant_Soil_Type = 'Any')...

and/or的另一种形式是使用IN（）子句，它更易于阅读、编辑，并且不太容易发生意外

WHERE Plant_Aspect.Plant_Aspect IN( 'East-facing' , 'Any' )
AND Plant_Soil_Type.Plant_Soil_Type IN( 'Sand' , 'Any' )
AND Plant_Moisture.Plant_Moisture IN( 'Well-drained' , 'Any' )
AND Plant_Soil_PH.Plant_Soil_PH IN( 'Acid' , 'Any' )
AND Plant_Foliage_Colour.Plant_Foliage_Colour IN( 'Green' )
AND Plant_Foliage_Colour.Plant_Season IN( 'Winter' , 'Any' )
AND Plant_Flower_Colour.Plant_Flower_Colour IN( 'Orange' )
AND Plant_Flower_Colour.Plant_Season IN( 'Winter' , 'Any' )

and/or的另一种形式是使用IN（）子句，它更易于阅读、编辑，并且不太容易发生意外

WHERE Plant_Aspect.Plant_Aspect IN( 'East-facing' , 'Any' )
AND Plant_Soil_Type.Plant_Soil_Type IN( 'Sand' , 'Any' )
AND Plant_Moisture.Plant_Moisture IN( 'Well-drained' , 'Any' )
AND Plant_Soil_PH.Plant_Soil_PH IN( 'Acid' , 'Any' )
AND Plant_Foliage_Colour.Plant_Foliage_Colour IN( 'Green' )
AND Plant_Foliage_Colour.Plant_Season IN( 'Winter' , 'Any' )
AND Plant_Flower_Colour.Plant_Flower_Colour IN( 'Orange' )
AND Plant_Flower_Colour.Plant_Season IN( 'Winter' , 'Any' )

+1：因为有一个完全不同的方法和一个整齐的缩放。谢谢，我不知道IN条款+1：因为有一个完全不同的方法和一个整齐的缩放。谢谢，我不知道IN条款！谢谢你的回答和时间。我并不知道你需要在AND或子句周围加括号。每天学习新的东西！在编写查询时，您需要满足两个受众：DBMS和其他程序员（比如6个月后的您自己）。他们都需要理解你写的东西。DBMS理解您编写的内容，并正确执行您编写的查询。问题是你写的和你打算写的不一样。基本上，总是将你想要分组的术语分组在一起，要么放在括号中，要么使用替代技术，如in子句。谢谢你的回答和时间。我并不知道你需要在AND或子句周围加括号。每天学习新的东西！在编写查询时，您需要满足两个受众：DBMS和其他程序员（比如6个月后的您自己）。他们都需要理解你写的东西。DBMS理解您编写的内容，并正确执行您编写的查询。问题是你写的和你打算写的不一样。基本上，总是将要分组的术语分组在一起，可以放在括号中，也可以使用替代技术，例如in子句。