[mysql] backport rename_index from Rails (corectly handling MariaDB as well)

rails/rails@1133818

Author: kares

lib/arjdbc/mysql/adapter.rb

@@ -238,9 +238,14 @@ def supports_views?
       version[0] && version[0] >= 5
     end
 
+    def supports_rename_index?
+      return false if mariadb? || ! version[0]
+      (version[0] == 5 && version[1] >= 7) || version[0] >= 6
+    end
+
     # @override
     def supports_transaction_isolation?(level = nil)
-      version[0] >= 5 # MySQL 5+
+      version[0] && version[0] >= 5 # MySQL 5+
     end
 
     # NOTE: handled by JdbcAdapter we override only to have save-point in logs :
@@ -411,6 +416,10 @@ def create_table(name, options = {})
       super(name, {:options => "ENGINE=InnoDB DEFAULT CHARSET=utf8"}.merge(options))
     end
 
+    def drop_table(table_name, options = {})
+      execute "DROP#{' TEMPORARY' if options[:temporary]} TABLE #{quote_table_name(table_name)}"
+    end
+
     # @override
     def rename_table(table_name, new_name)
       execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}"
@@ -423,6 +432,15 @@ def remove_index!(table_name, index_name)
       execute "DROP INDEX #{quote_column_name(index_name)} ON #{quote_table_name(table_name)}"
     end
 
+    # @override
+    def rename_index(table_name, old_name, new_name)
+      if supports_rename_index?
+        execute "ALTER TABLE #{quote_table_name(table_name)} RENAME INDEX #{quote_table_name(old_name)} TO #{quote_table_name(new_name)}"
+      else
+        super
+      end
+    end
+
     # @override
     def add_column(table_name, column_name, type, options = {})
       add_column_sql = "ALTER TABLE #{quote_table_name(table_name)} ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"
@@ -616,6 +634,8 @@ def column_for(table_name, column_name)
       column
     end
 
+    def mariadb?; !! ( full_version =~ /mariadb/i ) end
+
     def version
       return @version ||= begin
         version = []
@@ -625,9 +645,7 @@ def version
           version << jdbc_connection.serverMinorVersion
           version << jdbc_connection.serverSubMinorVersion
         else
-          result = execute 'SELECT VERSION()', 'SCHEMA'
-          result = result.first.values.first # [{"VERSION()"=>"5.5.37-0ubuntu..."}]
-          if match = result.match(/^(\d)\.(\d+)\.(\d+)/)
+          if match = full_version.match(/^(\d)\.(\d+)\.(\d+)/)
             version << match[1].to_i
             version << match[2].to_i
             version << match[3].to_i
@@ -637,6 +655,13 @@ def version
       end
     end
 
+    def full_version
+      @full_version ||= begin
+        result = execute 'SELECT VERSION()', 'SCHEMA'
+        result.first.values.first # [{"VERSION()"=>"5.5.37-0ubuntu..."}]
+      end
+    end
+
   end
 end