Sets up the select methods to use SQL_CALC_FOUND_ROWS option.
dataset.calc_found_rows.limit(10) # SELECT SQL_CALC_FOUND_ROWS * FROM table LIMIT 10
# File lib/sequel/adapters/shared/mysql.rb, line 747 def calc_found_rows clone(:calc_found_rows => true) end
MySQL specific syntax for LIKE/REGEXP searches, as well as string concatenation.
# File lib/sequel/adapters/shared/mysql.rb, line 687 def complex_expression_sql_append(sql, op, args) case op when :IN, :"NOT IN" ds = args[1] if ds.is_a?(Sequel::Dataset) && ds.opts[:limit] super(sql, op, [args[0], ds.from_self]) else super end when :~, :'!~', :'~*', :'!~*', :LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE' sql << '(' literal_append(sql, args[0]) sql << ' ' sql << 'NOT ' if [:'NOT LIKE', :'NOT ILIKE', :'!~', :'!~*'].include?(op) sql << ([:~, :'!~', :'~*', :'!~*'].include?(op) ? 'REGEXP' : 'LIKE') sql << ' ' sql << 'BINARY ' if [:~, :'!~', :LIKE, :'NOT LIKE'].include?(op) literal_append(sql, args[1]) if [:LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE'].include?(op) sql << " ESCAPE " literal_append(sql, "\\") end sql << ')' when :'||' if args.length > 1 sql << "CONCAT" array_sql_append(sql, args) else literal_append(sql, args[0]) end when :'B~' sql << "CAST(~" literal_append(sql, args[0]) sql << " AS SIGNED INTEGER)" else super end end
MySQL’s CURRENT_TIMESTAMP does not use fractional seconds, even if the database itself supports fractional seconds. If MySQL 5.6.4+ is being used, use a value that will return fractional seconds.
# File lib/sequel/adapters/shared/mysql.rb, line 730 def constant_sql_append(sql, constant) if constant == :CURRENT_TIMESTAMP && supports_timestamp_usecs? sql << 'CURRENT_TIMESTAMP(6)' else super end end
Sets up the select methods to delete from if deleting from a joined dataset:
DB[:a].join(:b, :a_id=>:id).delete # DELETE a FROM a INNER JOIN b ON (b.a_id = a.id) DB[:a].join(:b, :a_id=>:id).delete_from(:a, :b).delete # DELETE a, b FROM a INNER JOIN b ON (b.a_id = a.id)
# File lib/sequel/adapters/shared/mysql.rb, line 759 def delete_from(*tables) clone(:delete_from=>tables) end
Use GROUP BY instead of DISTINCT ON if arguments are provided.
# File lib/sequel/adapters/shared/mysql.rb, line 739 def distinct(*args) args.empty? ? super : group(*args) end
Return the results of an EXPLAIN query as a string. Options:
# File lib/sequel/adapters/shared/mysql.rb, line 765 def explain(opts=OPTS) # Load the PrettyTable class, needed for explain output Sequel.extension(:_pretty_table) unless defined?(Sequel::PrettyTable) ds = db.send(:metadata_dataset).with_sql((opts[:extended] ? 'EXPLAIN EXTENDED ' : 'EXPLAIN ') + select_sql).naked rows = ds.all Sequel::PrettyTable.string(rows, ds.columns) end
Adds full text filter
# File lib/sequel/adapters/shared/mysql.rb, line 780 def full_text_search(cols, terms, opts = OPTS) where(full_text_sql(cols, terms, opts)) end
MySQL specific full text search syntax.
# File lib/sequel/adapters/shared/mysql.rb, line 785 def full_text_sql(cols, terms, opts = OPTS) terms = terms.join(' ') if terms.is_a?(Array) SQL::PlaceholderLiteralString.new((opts[:boolean] ? MATCH_AGAINST_BOOLEAN : MATCH_AGAINST), [Array(cols), terms]) end
Sets up the insert methods to use INSERT IGNORE. Useful if you have a unique key and want to just skip inserting rows that violate the unique key restriction.
dataset.insert_ignore.multi_insert( [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}] ) # INSERT IGNORE INTO tablename (name, value) VALUES (a, 1), (b, 2)
# File lib/sequel/adapters/shared/mysql.rb, line 819 def insert_ignore clone(:insert_ignore=>true) end
Transforms an CROSS JOIN to an INNER JOIN if the expr is not nil. Raises an error on use of :full_outer type, since MySQL doesn’t support it.
# File lib/sequel/adapters/shared/mysql.rb, line 792 def join_table(type, table, expr=nil, opts=OPTS, &block) type = :inner if (type == :cross) && !expr.nil? raise(Sequel::Error, "MySQL doesn't support FULL OUTER JOIN") if type == :full_outer super(type, table, expr, opts, &block) end
Transforms :natural_inner to NATURAL LEFT JOIN and straight to STRAIGHT_JOIN.
# File lib/sequel/adapters/shared/mysql.rb, line 800 def join_type_sql(join_type) case join_type when :straight 'STRAIGHT_JOIN' when :natural_inner 'NATURAL LEFT JOIN' else super end end
Sets up the insert methods to use ON DUPLICATE KEY UPDATE If you pass no arguments, ALL fields will be updated with the new values. If you pass the fields you want then ONLY those field will be updated. If you pass a hash you can customize the values (for example, to increment a numeric field).
Useful if you have a unique key and want to update inserting rows that violate the unique key restriction.
dataset.on_duplicate_key_update.multi_insert( [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}] ) # INSERT INTO tablename (name, value) VALUES (a, 1), (b, 2) # ON DUPLICATE KEY UPDATE name=VALUES(name), value=VALUES(value) dataset.on_duplicate_key_update(:value).multi_insert( [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}] ) # INSERT INTO tablename (name, value) VALUES (a, 1), (b, 2) # ON DUPLICATE KEY UPDATE value=VALUES(value) dataset.on_duplicate_key_update( :value => Sequel.lit('value + VALUES(value)') ).multi_insert( [{:name => 'a', :value => 1}, {:name => 'b', :value => 2}] ) # INSERT INTO tablename (name, value) VALUES (a, 1), (b, 2) # ON DUPLICATE KEY UPDATE value=value + VALUES(value)
# File lib/sequel/adapters/shared/mysql.rb, line 852 def on_duplicate_key_update(*args) clone(:on_duplicate_key_update => args) end
MySQL uses the nonstandard ` (backtick) for quoting identifiers.
# File lib/sequel/adapters/shared/mysql.rb, line 857 def quoted_identifier_append(sql, c) sql << '`' << c.to_s.gsub('`', '``') << '`' end
MySQL does not support derived column lists
# File lib/sequel/adapters/shared/mysql.rb, line 862 def supports_derived_column_lists? false end
MySQL can emulate DISTINCT ON with its non-standard GROUP BY implementation, though the rows returned cannot be made deterministic through ordering.
# File lib/sequel/adapters/shared/mysql.rb, line 868 def supports_distinct_on? true end
MySQL supports GROUP BY WITH ROLLUP (but not CUBE)
# File lib/sequel/adapters/shared/mysql.rb, line 873 def supports_group_rollup? true end
MySQL does not support INTERSECT or EXCEPT
# File lib/sequel/adapters/shared/mysql.rb, line 878 def supports_intersect_except? false end
MySQL supports modifying joined datasets
# File lib/sequel/adapters/shared/mysql.rb, line 888 def supports_modifying_joins? true end
MySQL’s DISTINCT ON emulation using GROUP BY does not respect the queries ORDER BY clause.
# File lib/sequel/adapters/shared/mysql.rb, line 894 def supports_ordered_distinct_on? false end
MySQL supports pattern matching via regular expressions
# File lib/sequel/adapters/shared/mysql.rb, line 899 def supports_regexp? true end
MySQL does support fractional timestamps in literal timestamps, but it ignores them. Also, using them seems to cause problems on 1.9. Since they are ignored anyway, not using them is probably best.
# File lib/sequel/adapters/shared/mysql.rb, line 906 def supports_timestamp_usecs? db.supports_timestamp_usecs? end
Sets up the update methods to use UPDATE IGNORE. Useful if you have a unique key and want to just skip updating rows that violate the unique key restriction.
dataset.update_ignore.update({:name => 'a', :value => 1}) # UPDATE IGNORE tablename SET name = 'a', value = 1
# File lib/sequel/adapters/shared/mysql.rb, line 916 def update_ignore clone(:update_ignore=>true) end