Postgres, fix explain warnings and functionality (3 tests fails only due binds, we use ? instead of )

Author: JesseChavez

lib/arjdbc/postgresql/adapter.rb

@@ -22,6 +22,7 @@
 require 'arjdbc/postgresql/base/array_decoder'
 require 'arjdbc/postgresql/base/array_encoder'
 require 'arjdbc/postgresql/name'
+require 'arjdbc/postgresql/database_statements'
 require 'arjdbc/postgresql/schema_statements'
 
 require 'active_model'
@@ -477,11 +478,6 @@ def execute_batch(statements, name = nil)
       execute(combine_multi_statements(statements), name)
     end
 
-    def explain(arel, binds = [])
-      sql, binds = to_sql_and_binds(arel, binds)
-      ActiveRecord::ConnectionAdapters::PostgreSQL::ExplainPrettyPrinter.new.pp(exec_query("EXPLAIN #{sql}", 'EXPLAIN', binds))
-    end
-
     # from ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements
     READ_QUERY = ActiveRecord::ConnectionAdapters::AbstractAdapter.build_read_query_regexp(
       :close, :declare, :fetch, :move, :set, :show
@@ -809,6 +805,7 @@ class PostgreSQLAdapter < AbstractAdapter
 
     require 'arjdbc/postgresql/oid_types'
     include ::ArJdbc::PostgreSQL::OIDTypes
+    include ::ArJdbc::PostgreSQL::DatabaseStatements
     include ::ArJdbc::PostgreSQL::SchemaStatements
 
     include ::ArJdbc::PostgreSQL::ColumnHelpers

lib/arjdbc/postgresql/database_statements.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module ArJdbc
+  module PostgreSQL
+    module DatabaseStatements
+      def explain(arel, binds = [], options = [])
+        sql    = build_explain_clause(options) + " " + to_sql(arel, binds)
+        result = internal_exec_query(sql, "EXPLAIN", binds)
+        ActiveRecord::ConnectionAdapters::PostgreSQL::ExplainPrettyPrinter.new.pp(result)
+      end
+
+      def build_explain_clause(options = [])
+        return "EXPLAIN" if options.empty?
+
+        "EXPLAIN (#{options.join(", ").upcase})"
+      end
+    end
+  end
+end