Added concern for case-insensitive WHERE queries

On PostgreSQL these queries use LOWER(...) to compare columns and
values. For MySQL a regular WHERE is performed as MySQL is already
case-insensitive.

1 files changed, 28 insertions, 0 deletions

diff --git a/app/models/concerns/case_sensitivity.rb b/app/models/concerns/case_sensitivity.rb
new file mode 100644
index 00000000000..49d350e092b
--- /dev/null
+++ b/app/models/concerns/case_sensitivity.rb
@@ -0,0 +1,28 @@
+# Concern for querying columns with specific case sensitivity handling.
+module CaseSensitivity
+  extend ActiveSupport::Concern
+
+  module ClassMethods
+    # Queries the given columns regardless of the casing used.
+    #
+    # Unlike other ActiveRecord methods this method only operates on a Hash.
+    def case_insensitive_where(params)
+      criteria   = self
+      cast_lower = Gitlab::Database.postgresql?
+
+      params.each do |key, value|
+        column = ActiveRecord::Base.connection.quote_table_name(key)
+
+        if cast_lower
+          condition = "LOWER(#{column}) = LOWER(:value)"
+        else
+          condition = "#{column} = :value"
+        end
+
+        criteria = criteria.where(condition, value: value)
+      end
+
+      criteria
+    end
+  end
+end