Why filtering django with icontains is case sensitive?

Question

I want to filter a queryset with icontains because I don't want the filtration to be case sensitive:

some_title = "Foo"
result = Article.objects.filter(title__icontains=some_title)

articles with the title "foo" are not within the result. why? I am using Django (1.9.12).

Answer 1

I was using Mysql database with collation set to X_bin. I changed the collation of the article table with:

ALTER TABLE articles CHARACTER SET utf8 COLLATE utf8_general_ci;

to apply to all columns:

ALTER TABLE articles CONVERT TO CHARACTER SET utf8;

somehow the old collation uses another method of string comparison that does'nt respect letter case. the new collation utf8_general_ci does.