SQLite3 adapter supports expression indexes

2 files changed, 9 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
index 24e7bc65fa..0e254455b6 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3/schema_statements.rb
@@ -21,12 +21,16 @@ module ActiveRecord
               WHERE name = #{quote(row['name'])} AND type = 'index'
             SQL
 
-            /\sWHERE\s+(?<where>.+)$/i =~ index_sql
+            /\sON\s+"(\w+?)"\s+\((?<expressions>.+?)\)(\sWHERE\s+(?<where>.+))?$/i =~ index_sql
 
             columns = exec_query("PRAGMA index_info(#{quote(row['name'])})", "SCHEMA").map do |col|
               col["name"]
             end
 
+            if columns.any?(&:nil?) # index created with an expression
+              columns = expressions.split(", ").map { |e| e.gsub(/^\"|\"?$/, "") }
+            end
+
             # Add info on sort order for columns (only desc order is explicitly specified, asc is
             # the default)
             orders = {}
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index efe454fa7f..51f4944808 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -125,6 +125,10 @@ module ActiveRecord
         true
       end
 
+      def supports_expression_index?
+        sqlite_version >= "3.9.0"
+      end
+
       def requires_reloading?
         true
       end