Question

如果我的编码在Categroy和Catecode中匹配

，我如何获得城市

"id"    "City"      "category"  "CatCode" "country"
"1"     "NewYork"   "0"         "101"     "US"
"2"     "Alaska"    "1"         "102"     "US"
"3"     "NewOrln"   "3"         "101"     "US"
"4"     "MashSh"    "4"         "102"     "US"

拜托，您可以帮忙查询吗？谢谢。

我需要结果例如果说选择国家，如果类别= 4并且CateCode = 101 我需要结果是美国由于4存在于Category中，101存在于CateCode中。

谢谢

Answer 1

如果您搜索匹配的城市，例如，在表格中输入类别= 3和catcode = 101：

Select city from your_table_name WHERE category=3 AND catcode=101;

Answer 2

你需要一个不相交的条件。

 select city from your_table_name where  
 catcode=101 OR category=3;

Answer 3

我猜你想要这样的东西：

SELECT country
FROM theTable
WHERE country IN (SELECT country FROM theTable WHERE category = 4)
   AND country IN (SELECT country FROM theTable WHERE catcode = 101)

代表我认为你正在寻找的更直接/字面意义;但从技术上讲，这应该更快（因为它少了一个子查询）：

SELECT country
FROM theTable
WHERE category = 4
   AND country IN (SELECT country FROM theTable WHERE catcode = 101)

MYSQL选择条件是否与Column1和Column2中的ANYTHING匹配

3 个答案: