Question

我有两个SQL表：

PROPERTY
PID  Address
1   123 Center Road
2   23 North Road
3   3a/34 Crest Avenue
5   49 Large Road
6   2 Kingston Way
7   4/232 Center Road
8   2/19 Ash Grove
9   54 Vintage Street
10  15 Charming Street

PROPERTY_FEATURE
P.PID  Feature    
1      Wine Cellar
1      Helipad
2      Tennis Court
2      Showroom
7      Swimming Pool - Above Ground
9      Swimming Pool - Below Ground
9      Wine Cellar

我想选择包含特定功能的属性。例如，我想选择具有Wine Cellar和Helipad功能的属性ID，它将返回ID为1的Property。

有什么想法吗？

Answer 1

您可以使用WebElement contextNode=driver.findElement(By.xpath("/html/body")); if(driver instanceof JavascriptExecutor) { String jswalker= "var tw = document.createTreeWalker(" + "arguments[0]," + "NodeFilter.SHOW_TEXT," + "{ acceptNode: function(node) { return NodeFilter.FILTER_ACCEPT;} }," + "false" + ");" + "var ret=null;" // skip over the number of text nodes indicated by the arguments[1] + "var skip;" + "for(skip=0; tw.nextNode() && skip<arguments[1]; skip++);" + "if(skip==arguments[1]) { " // found before tw.nextNode() ran out + "ret=tw.currentNode.wholeText.trim();" + "}" + "return ret;" ; int textNodeIndex=3; // there will be empty text nodes before after <b> Object val=((JavascriptExecutor) driver).executeScript( jswalker, contextNode, textNodeIndex ); String textThatINeed=(null!=val ? val.toString() : null); }和Group By子句

执行此操作

Having

1）select PID From PROPERTY_FEATURE Group by PID Having COUNT(case when Feature = 'Wine Cellar' then 1 end) > 0 --1 and COUNT(case when Feature = 'Helipad' then 1 end) > 0 -- 2仅在Counts＆amp; Feature = 'Wine Cellar'会确保每个> 0

至少存在一个'Wine Cellar'

2）PID仅在Counts＆amp; Feature = 'Helipad'会确保每个> 0

至少存在一个'Helipad'

PID将确保1＆amp; 2满足然后返回AND

Answer 2

您可以通过过滤所需的功能，然后在HAVING子句中进行分组和计数来完成此操作。您也可以直接分组（不先过滤），但如果表格非常大，有很多pid，那么将导致大量不必要的行分组，最终不会使用。

这样的事情：

select pid
from   property_feature
where  feature in ('Wine Cellar', 'Helipad')
group by pid
having count(feature) = 2;

这假设表格中没有重复项（因此您不能两次1 'Helipad'，弄乱计数）。如果可以重复，请将最后一行更改为count (distinct feature) = 2。

从Property_Features列表中选择Properties

2 个答案: