Enabled matches_regex for MySql

Previously matches_regex was only availble on PostgreSql, this will enable it for MySql

Usage example:

    users = User.arel_table;
    users = User.arel_table; User.where(users[:email].matches_regexp('(.*)\@gmail.com'))

Update activerecord/test/cases/arel/visitors/mysql_test.rb

Co-Authored-By: Ryuta Kamizono <kamipo@gmail.com>

3 files changed, 58 insertions, 0 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 7f2071189b..919905e884 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,7 @@
+*   Allow matches_regex on MySQL 
+
+    *James Pearson*
+    
 *   Allow specifying fixtures to be ignored by setting `ignore` in YAML file's '_fixture' section.
 
     *Tongfei Gao*
diff --git a/activerecord/lib/arel/visitors/mysql.rb b/activerecord/lib/arel/visitors/mysql.rb
index dd77cfdf66..6cb866715f 100644
--- a/activerecord/lib/arel/visitors/mysql.rb
+++ b/activerecord/lib/arel/visitors/mysql.rb
@@ -48,6 +48,14 @@ module Arel # :nodoc: all
           visit_Arel_Nodes_IsNotDistinctFrom o, collector
         end
 
+        def visit_Arel_Nodes_Regexp(o, collector)
+          infix_value o, collector, " REGEXP "
+        end
+
+        def visit_Arel_Nodes_NotRegexp(o, collector)
+          infix_value o, collector, " NOT REGEXP "
+        end
+
         # In the simple case, MySQL allows us to place JOINs directly into the UPDATE
         # query. However, this does not allow for LIMIT, OFFSET and ORDER. To support
         # these, we must use a subquery.
diff --git a/activerecord/test/cases/arel/visitors/mysql_test.rb b/activerecord/test/cases/arel/visitors/mysql_test.rb
index 5f37587957..05dccd126e 100644
--- a/activerecord/test/cases/arel/visitors/mysql_test.rb
+++ b/activerecord/test/cases/arel/visitors/mysql_test.rb
@@ -104,6 +104,52 @@ module Arel
           sql.must_be_like %{ NOT "users"."name" <=> NULL }
         end
       end
+
+      describe "Nodes::Regexp" do
+        before do
+          @table = Table.new(:users)
+          @attr = @table[:id]
+        end
+
+        it "should know how to visit" do
+          node = @table[:name].matches_regexp("foo.*")
+          node.must_be_kind_of Nodes::Regexp
+          compile(node).must_be_like %{
+            "users"."name" REGEXP 'foo.*'
+          }
+        end
+
+        it "can handle subqueries" do
+          subquery = @table.project(:id).where(@table[:name].matches_regexp("foo.*"))
+          node = @attr.in subquery
+          compile(node).must_be_like %{
+            "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" REGEXP 'foo.*')
+          }
+        end
+      end
+
+      describe "Nodes::NotRegexp" do
+        before do
+          @table = Table.new(:users)
+          @attr = @table[:id]
+        end
+
+        it "should know how to visit" do
+          node = @table[:name].does_not_match_regexp("foo.*")
+          node.must_be_kind_of Nodes::NotRegexp
+          compile(node).must_be_like %{
+            "users"."name" NOT REGEXP 'foo.*'
+          }
+        end
+
+        it "can handle subqueries" do
+          subquery = @table.project(:id).where(@table[:name].does_not_match_regexp("foo.*"))
+          node = @attr.in subquery
+          compile(node).must_be_like %{
+            "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" NOT REGEXP 'foo.*')
+          }
+        end
+      end
     end
   end
 end