Question

I need to select data from two different tables to create a history/ archive for my website like this:

2012

• August(6)
• September(4)
• October(2)

I’m aware that there is a question similar to this in stackoverflow: PHP MYSQL Blog Archive Menu by Year and Month

However, I have two similar yet different tables.

I have tried using this example: mysql select data from two tables and different structure, but I always get the error of “#1271 – Illegal mix of collations for operation ‘UNION'”

Is there any other ways that I can combine to get my data like above?

My two tables’ fields and structures are:

1) news

• id (int 5)
• title (varchar 200)
• content (text)
• date_added (datetime)

2) equipment

• id (int 5)
• title (varchar 45)
• content (varchar 250)
• date_added (date)

Note: The tables’ id are their own individual id for the article. My tables haven nothing in common with each other.

Answer 1

At first I thought the data types were the issue and you needed to cast the types to match:

SELECT id, title, content, cast(date_added as Date) FROM NEWS
UNION ALL 
SELECT id, title, cast(content as text), date_added FROM EQUIPMENT;

However when I tried it out myself I found all types converted implicitly. I took another look at your description and delved deeper into the collation issue. It’s my belief that the content column in the news table is either a different character set and/or a different collation type from the content column in the Equipment table. This could be true for the title columns or the whole tables. You need to try converting. I would suggest this:

SELECT 
  id, 
  convert(title using utf8) collate utf8_bin, 
  convert(content using utf8) collate utf8_bin, 
  date_added 
FROM 
  NEWS
UNION ALL

SELECT 
  id, 
  convert(title using utf8) collate utf8_bin, 
  convert(content using utf8) collate utf8_bin, 
  date_added 
FROM 
  EQUIPMENT;

That should solve your problem.