请帮忙！在SQL中选择查询 [英] Please help! Select query in SQL

问题描述

 ID名称指定级别userid 
  15 Sh。 B.M. Babbar SDE-R2 00010104 ELE15  
 16 Sh。 Surinder AE-R2 0001010401 ELE16 
 17 Sh。 Roop Lal JE-R2 000101040101 ELE17 
 18 Sh。 Mansatinder JE-R3 000101040102 ELE18 
 328 testnews JE_R2 000101040103 JE_R2 
 329 testnews JE_R2 000101040104 JE_R2 
 330 testnew12 AE-R3 000101040105 AE-R3 
 331 testnews AE-R3 000101040106 AE-R3 

这是我的employeeList表及上表下面的结果，显示sde（SDE-R2）作为父下AE作为儿童和AE（AE-R2）在JE下作为子孙desiganation。我想通过级别获得AE数据下的sde



i尝试此查询从EmployeeList中选择*，其中级别如'00010104％' 但显示所有记录



我尝试过：



i想要仅按父母数据显示子数据（SDE-R2 00010104）

  16 Sh.Surinder AE-R2 0001010401 ELE16  

解决方案

我想通过父数据显示子数据（SDE-R2 00010104）



psuedo sql查询是：

从<<< ChildTable>>中选择* 
内部联接<< ParentTable>> 
 on< childtable.FKID>> =<< ParentTable.PKID>> 
其中<< ParentTable。<< level>>比如'00010104％'

我认为你应该永远不要使用选择* 在生产查询中，因为如果某些事情随着所涉及的所有表格的结构而改变，这将对您的数据路径产生负面影响。



选择* 适用于测试和数据转储，但这就是它，恕我直言。

因为你只想要此查询下面的级别应该完成这项工作：

  SELECT  * 
  FROM  EmployeeList 
  WHERE  LEVEL  LIKE  '  00010104 __' 

但是基于位置的层次结构键是我建议你重新考虑一下。



是的，永远不要在生产鳕鱼中使用 SELECT * e。

我认为解决方案1得到了错误的结束。根据您的注释，您只需要在查询中添加AND子句（并且如Slacker007所指出的那样，更正列列表）。例如

 选择 ID，名称，名称，级别，用户ID 
 来自 EmployeeList 其中​​级别喜欢 '  00010104％' 
  和名称喜欢 '  AE％'  

如果你还想包括你提到的子子名称，那么添加一个OR子句但是你需要将它括在括号中，例如

 从 ID，名称，名称，级别，用户ID 
  > EmployeeList 其中级别喜欢 '  00010104％' 
 和（指定喜欢 '  AE％' 或指定< span class =code-keyword> like  '  JE％'）

ID	Name	   Designation	Level	        userid
15	Sh. B.M. Babbar	SDE-R2	00010104	       ELE15
16	Sh. Surinder  	AE-R2	0001010401	        ELE16
17	Sh. Roop Lal	JE-R2	000101040101	ELE17
18	Sh. Mansatinder	JE-R3	000101040102	ELE18
328	testnews	    JE_R2	000101040103	JE_R2
329	testnews	   JE_R2	000101040104	JE_R2
330	testnew12	   AE-R3	000101040105	AE-R3
331	testnews	   AE-R3    000101040106	AE-R3

This my employeeList table and above following table result showing sde(SDE-R2) as parent under AE as child and AE(AE-R2) under JE as subchild desiganation. i want to get only sde under AE Data through by level

i try this query "Select * from EmployeeList where level like '00010104%'" but showing all records

What I have tried:

i want to show only child data by parent data (SDE-R2 00010104)
"

16	Sh. Surinder  	AE-R2	0001010401	        ELE16

"

解决方案

i want to show only child data by parent data (SDE-R2 00010104)

psuedo sql query is:

Select * from <<ChildTable>>
Inner join <<ParentTable>>
on <childtable.FKID>> = <<ParentTable.PKID>>
Where <<ParentTable.<<level>> like '00010104%'

I think it important to mention that you should never use Select * in a production query, as that can have negative implications for your data path in the future if something were to change with the structure of all the tables involved.

Select * is good for testing and for data dumps, but that is about it, IMHO.

Since you only want the level below this query should do the job:

SELECT   *
FROM    EmployeeList
WHERE   LEVEL LIKE '00010104__'

But having a position based hierarchy key is something I'd recommend that you rethink.

And yes, never use SELECT * in production code.

I think solution 1 got the wrong end of the stick. Based on your comment you just need to add and AND clause to your query (and as pointed out by Slacker007, correct your column list). E.g.

Select ID, Name, Designation, Level, userid
from EmployeeList where level like '00010104%'
and Designation like 'AE%'

If you also want to include the "sub-child" designation you mention then add an OR clause but you will need to enclose it in brackets e.g.

Select ID, Name, Designation, Level, userid
from EmployeeList where level like '00010104%'
and ( Designation like 'AE%' or Designation like 'JE%' )

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