如何从MySQL查询结果的特定列中查找值？

Question

I have a table with the following columns: id, firstname, lastname, category. And let's say i have data with categories like: action, comedy, drama, horror. My query is

SELECT * FROM tablename WHERE firstname LIKE '%John%'

The query will bring all the records that contain 'John' in firstname, and let's assume that the records have different values for categoty: action and comedy only.

How to find out the list with all the values available in category column for this specific search.

Thanks!

Answer 1

如果您想要一个不同的类别列表，则名字类似于John：

SELECT DISTINCT category FROM tablename WHERE firstname LIKE '%John%'

Answer 2

try this:

SELECT * 
FROM tablename 
WHERE firstname LIKE '%John%' 
and category='category_name'

Answer 3

SELECT category FROM tablename WHERE firstname LIKE '%John%' 

看起来很简单

Answer 4

如果您希望类别列表中包含出现次数：

SELECT DISTINCT CATEGORY, COUNT(*) AS Total FROM tablename WHERE firstname LIKE '%John%' GROUP BY CATEGORY ORDER BY CATEGORY