Question

很多时候，我想用一个@variable来检查CTE内某个查询的结果，而不必在末尾添加select * from cte来改变整个事情。

一个例子是这样的：

declare @From date
declare @To date
declare @city varchar(20)
declare @st varchar(5)

// Lots of code that sets all the @variables

;with cteSales as
(
    select * from MyTable 
    where 
    From = @From and To = @To and 
    salesman = @salesman and city = @city and st = @st
) 
//HERE GOES A LONG QUERY THAT USES cteSales

我知道在CTE中调试查询的唯一方法是1）用值替换变量并执行查询，或者2）在cteSales之后注释所有内容并添加select * from cteSales。

后者不太舒服，但是两者都需要从原始代码中进行很多更改。

是否可以在不使用以上两个选项中的任何一个的情况下，在select中调试cte台？

Answer 1

使用您的代码示例，另一种方法是：

declare @From date
declare @To date
declare @city varchar(20)
declare @st varchar(5)

// Lots of code that sets all the @variables

--;with cteSales as   --comment these two lines out for testing
--(
    select * from MyTable 
    where 
    From = @From and To = @To and 
    salesman = @salesman and city = @city and st = @st  --highlight the code up to here and execute
) 
//HERE GOES A LONG QUERY THAT USES cteSales

编辑以回应：

我当时在想IDE具有一些晦涩的隐藏功能，让我查看cte的结果，而不必更改整体查询

在这种情况下，答案是否定的。 IDE中没有类似的东西。

Answer 2

您也可以将很长的查询也包装到cte中，然后在底部只需注释掉一行即可。

import numpy as np
import pandas as pd
from  sklearn.neighbors import KDTree


np.random.seed(0)
#since you have df1 and df2, you will want to convert the dfs to array here with
#X=df1['x'.'y','z'].to_numpy()
#Y=df2['x','y','z'.to_numpy()
n=11    #n=number of dimensions in your sample
X = np.random.random((10, n))  # 10 points in n dimensions
Y = np.random.random((10, n))
tree = KDTree(Y, leaf_size=2)  

indices=[]
#for i in range(len(X)):
    #loop though the x array and find the closest point in y to each x       
dist, ind = tree.query(X, k=1) 
#indices.append(ind)     
df1=pd.DataFrame(X)  
##set the labels to the closest point to each neighbor
df1['label']=ind

最后，如果您使用的是SQL Management Studio，请使用快捷键;with cteSales as ( select * from MyTable where From = @From and To = @To and salesman = @salesman and city = @city and st = @st ) , cteVeryLongQuery as ( //HERE GOES A LONG QUERY THAT USES cteSales ) SELECT * FROM cteVeryLongQuery -- SELECT * FROM cteSales -- Uncomment this for debugging `cteSales` and comment out the line above.注释掉行，并使用Ctrl+K+C取消注释。

使用变量调试CTE？

2 个答案: