Put all `explain` methods into `DatabaseStatements` module

Almost all database statements methods except `explain` was moved into
`DatabaseStatements` at #35922. This moves the last one method.

1 files changed, 9 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
index 2132e5d248..bbcdc96cdc 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
@@ -26,6 +26,15 @@ module ActiveRecord
           !READ_QUERY.match?(sql)
         end
 
+        def explain(arel, binds = [])
+          sql     = "EXPLAIN #{to_sql(arel, binds)}"
+          start   = Concurrent.monotonic_time
+          result  = exec_query(sql, "EXPLAIN", binds)
+          elapsed = Concurrent.monotonic_time - start
+
+          MySQL::ExplainPrettyPrinter.new.pp(result, elapsed)
+        end
+
         # Executes the SQL statement in the context of this connection.
         def execute(sql, name = nil)
           if preventing_writes? && write_query?(sql)