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-rw-r--r--activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb78
-rw-r--r--activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb78
-rw-r--r--activerecord/lib/active_record/connection_adapters/mysql_adapter.rb8
-rw-r--r--activerecord/test/cases/adapters/mysql/explain_test.rb27
4 files changed, 113 insertions, 78 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index c084431588..ea46512660 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -272,6 +272,10 @@ module ActiveRecord
version[0] >= 5
end
+ def supports_explain?
+ true
+ end
+
def supports_indexes_in_create?
true
end
@@ -365,6 +369,80 @@ module ActiveRecord
# DATABASE STATEMENTS ======================================
#++
+ def explain(arel, binds = [])
+ sql = "EXPLAIN #{to_sql(arel, binds)}"
+ start = Time.now
+ result = exec_query(sql, 'EXPLAIN', binds)
+ elapsed = Time.now - start
+
+ ExplainPrettyPrinter.new.pp(result, elapsed)
+ end
+
+ class ExplainPrettyPrinter # :nodoc:
+ # Pretty prints the result of a EXPLAIN in a way that resembles the output of the
+ # MySQL shell:
+ #
+ # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
+ # | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+ # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
+ # | 1 | SIMPLE | users | const | PRIMARY | PRIMARY | 4 | const | 1 | |
+ # | 1 | SIMPLE | posts | ALL | NULL | NULL | NULL | NULL | 1 | Using where |
+ # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
+ # 2 rows in set (0.00 sec)
+ #
+ # This is an exercise in Ruby hyperrealism :).
+ def pp(result, elapsed)
+ widths = compute_column_widths(result)
+ separator = build_separator(widths)
+
+ pp = []
+
+ pp << separator
+ pp << build_cells(result.columns, widths)
+ pp << separator
+
+ result.rows.each do |row|
+ pp << build_cells(row, widths)
+ end
+
+ pp << separator
+ pp << build_footer(result.rows.length, elapsed)
+
+ pp.join("\n") + "\n"
+ end
+
+ private
+
+ def compute_column_widths(result)
+ [].tap do |widths|
+ result.columns.each_with_index do |column, i|
+ cells_in_column = [column] + result.rows.map {|r| r[i].nil? ? 'NULL' : r[i].to_s}
+ widths << cells_in_column.map(&:length).max
+ end
+ end
+ end
+
+ def build_separator(widths)
+ padding = 1
+ '+' + widths.map {|w| '-' * (w + (padding*2))}.join('+') + '+'
+ end
+
+ def build_cells(items, widths)
+ cells = []
+ items.each_with_index do |item, i|
+ item = 'NULL' if item.nil?
+ justifier = item.is_a?(Numeric) ? 'rjust' : 'ljust'
+ cells << item.to_s.send(justifier, widths[i])
+ end
+ '| ' + cells.join(' | ') + ' |'
+ end
+
+ def build_footer(nrows, elapsed)
+ rows_label = nrows == 1 ? 'row' : 'rows'
+ "#{nrows} #{rows_label} in set (%.2f sec)" % elapsed
+ end
+ end
+
def clear_cache!
super
reload_type_map
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
index 21631be25c..77ab30e5d7 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
@@ -37,10 +37,6 @@ module ActiveRecord
configure_connection
end
- def supports_explain?
- true
- end
-
# HELPER METHODS ===========================================
def each_hash(result) # :nodoc:
@@ -95,80 +91,6 @@ module ActiveRecord
# DATABASE STATEMENTS ======================================
#++
- def explain(arel, binds = [])
- sql = "EXPLAIN #{to_sql(arel, binds.dup)}"
- start = Time.now
- result = exec_query(sql, 'EXPLAIN', binds)
- elapsed = Time.now - start
-
- ExplainPrettyPrinter.new.pp(result, elapsed)
- end
-
- class ExplainPrettyPrinter # :nodoc:
- # Pretty prints the result of a EXPLAIN in a way that resembles the output of the
- # MySQL shell:
- #
- # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
- # | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
- # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
- # | 1 | SIMPLE | users | const | PRIMARY | PRIMARY | 4 | const | 1 | |
- # | 1 | SIMPLE | posts | ALL | NULL | NULL | NULL | NULL | 1 | Using where |
- # +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
- # 2 rows in set (0.00 sec)
- #
- # This is an exercise in Ruby hyperrealism :).
- def pp(result, elapsed)
- widths = compute_column_widths(result)
- separator = build_separator(widths)
-
- pp = []
-
- pp << separator
- pp << build_cells(result.columns, widths)
- pp << separator
-
- result.rows.each do |row|
- pp << build_cells(row, widths)
- end
-
- pp << separator
- pp << build_footer(result.rows.length, elapsed)
-
- pp.join("\n") + "\n"
- end
-
- private
-
- def compute_column_widths(result)
- [].tap do |widths|
- result.columns.each_with_index do |column, i|
- cells_in_column = [column] + result.rows.map {|r| r[i].nil? ? 'NULL' : r[i].to_s}
- widths << cells_in_column.map(&:length).max
- end
- end
- end
-
- def build_separator(widths)
- padding = 1
- '+' + widths.map {|w| '-' * (w + (padding*2))}.join('+') + '+'
- end
-
- def build_cells(items, widths)
- cells = []
- items.each_with_index do |item, i|
- item = 'NULL' if item.nil?
- justifier = item.is_a?(Numeric) ? 'rjust' : 'ljust'
- cells << item.to_s.send(justifier, widths[i])
- end
- '| ' + cells.join(' | ') + ' |'
- end
-
- def build_footer(nrows, elapsed)
- rows_label = nrows == 1 ? 'row' : 'rows'
- "#{nrows} #{rows_label} in set (%.2f sec)" % elapsed
- end
- end
-
# FIXME: re-enable the following once a "better" query_cache solution is in core
#
# The overrides below perform much better than the originals in AbstractAdapter
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 64985ee933..23875f3f4e 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -184,6 +184,14 @@ module ActiveRecord
# DATABASE STATEMENTS ======================================
#++
+ def select_all(arel, name = nil, binds = [])
+ if ExplainRegistry.collect? && prepared_statements
+ unprepared_statement { super }
+ else
+ super
+ end
+ end
+
def select_rows(sql, name = nil, binds = [])
@connection.query_with_result = true
rows = exec_query(sql, name, binds).rows
diff --git a/activerecord/test/cases/adapters/mysql/explain_test.rb b/activerecord/test/cases/adapters/mysql/explain_test.rb
new file mode 100644
index 0000000000..f75386abb9
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql/explain_test.rb
@@ -0,0 +1,27 @@
+require "cases/helper"
+require 'models/developer'
+require 'models/computer'
+
+module ActiveRecord
+ module ConnectionAdapters
+ class MysqlAdapter
+ class ExplainTest < ActiveRecord::TestCase
+ fixtures :developers
+
+ def test_explain_for_one_query
+ explain = Developer.where(:id => 1).explain
+ assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers` WHERE `developers`.`id` = 1), explain
+ assert_match %r(developers |.* const), explain
+ end
+
+ def test_explain_with_eager_loading
+ explain = Developer.where(:id => 1).includes(:audit_logs).explain
+ assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers` WHERE `developers`.`id` = 1), explain
+ assert_match %r(developers |.* const), explain
+ assert_match %(EXPLAIN for: SELECT `audit_logs`.* FROM `audit_logs` WHERE `audit_logs`.`developer_id` = 1), explain
+ assert_match %r(audit_logs |.* ALL), explain
+ end
+ end
+ end
+ end
+end