Merge pull request #13040 from kamipo/case_sensitive_comparison

Only use BINARY for mysql case sensitive uniqueness check when column has a case insensitive collation.

Conflicts:
	activerecord/CHANGELOG.md

3 files changed, 14 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 11b28a4858..496153af83 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -340,6 +340,11 @@ module ActiveRecord
         node
       end
 
+      def case_sensitive_comparison(table, attribute, column, value)
+        value = case_sensitive_modifier(value) unless value.nil?
+        table[attribute].eq(value)
+      end
+
       def case_insensitive_comparison(table, attribute, column, value)
         table[attribute].lower.eq(table.lower(value))
       end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index baac9522b6..9a819720f7 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -592,6 +592,14 @@ module ActiveRecord
         Arel::Nodes::Bin.new(node)
       end
 
+      def case_sensitive_comparison(table, attribute, column, value)
+        if column.case_sensitive?
+          table[attribute].eq(value)
+        else
+          super
+        end
+      end
+
       def case_insensitive_comparison(table, attribute, column, value)
         if column.case_sensitive?
           super
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index 82c2b9439b..71c71cb4b1 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -68,8 +68,7 @@ module ActiveRecord
           # will use SQL LOWER function before comparison, unless it detects a case insensitive collation
           klass.connection.case_insensitive_comparison(table, attribute, column, value)
         else
-          value = klass.connection.case_sensitive_modifier(value) unless value.nil?
-          table[attribute].eq(value)
+          klass.connection.case_sensitive_comparison(table, attribute, column, value)
         end
       end