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 413 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 369 def complex_expression_sql_append(sql, op, args) case op when :IN, :"NOT IN" ds = args.at(1) if ds.is_a?(Sequel::Dataset) && ds.opts[:limit] super(sql, op, [args.at(0), ds.from_self]) else super end when :~, :'!~', :'~*', :'!~*', :LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE' sql << PAREN_OPEN literal_append(sql, args.at(0)) sql << SPACE sql << 'NOT ' if [:'NOT LIKE', :'NOT ILIKE', :'!~', :'!~*'].include?(op) sql << ([:~, :'!~', :'~*', :'!~*'].include?(op) ? REGEXP : LIKE) sql << SPACE sql << BINARY if [:~, :'!~', :LIKE, :'NOT LIKE'].include?(op) literal_append(sql, args.at(1)) sql << PAREN_CLOSE when :'||' if args.length > 1 sql << CONCAT array_sql_append(sql, args) else literal_append(sql, args.at(0)) end when :'B~' sql << CAST_BITCOMP_OPEN literal_append(sql, args.at(0)) sql << CAST_BITCOMP_CLOSE else super end end
Use GROUP BY instead of DISTINCT ON if arguments are provided.
# File lib/sequel/adapters/shared/mysql.rb, line 405 def distinct(*args) args.empty? ? super : group(*args) end
Adds full text filter
# File lib/sequel/adapters/shared/mysql.rb, line 423 def full_text_search(cols, terms, opts = {}) filter(full_text_sql(cols, terms, opts)) end
MySQL specific full text search syntax.
# File lib/sequel/adapters/shared/mysql.rb, line 428 def full_text_sql(cols, terms, opts = {}) terms = terms.join(' ') if terms.is_a?(Array) SQL::PlaceholderLiteralString.new("MATCH ? AGAINST (?#{" IN BOOLEAN MODE" if opts[:boolean]})", [Array(cols), terms], true) end
MySQL allows HAVING clause on ungrouped datasets.
# File lib/sequel/adapters/shared/mysql.rb, line 434 def having(*cond, &block) _filter(:having, *cond, &block) 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 467 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 440 def join_table(type, table, expr=nil, table_alias={}, &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, table_alias, &block) end
Transforms :natural_inner to NATURAL LEFT JOIN and straight to STRAIGHT_JOIN.
# File lib/sequel/adapters/shared/mysql.rb, line 448 def join_type_sql(join_type) case join_type when :straight STRAIGHT_JOIN when :natural_inner NATURAL_LEFT_JOIN else super end end
MySQL specific syntax for inserting multiple values at once.
# File lib/sequel/adapters/shared/mysql.rb, line 495 def multi_insert_sql(columns, values) sql = LiteralString.new('VALUES ') expression_list_append(sql, values.map{|r| Array(r)}) [insert_sql(columns, sql)] 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.
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)
# File lib/sequel/adapters/shared/mysql.rb, line 490 def on_duplicate_key_update(*args) clone(:on_duplicate_key_update => args) end
MySQL uses the number of rows actually modified in the update, instead of the number of matched by the filter.
# File lib/sequel/adapters/shared/mysql.rb, line 503 def provides_accurate_rows_matched? false end
MySQL uses the nonstandard ` (backtick) for quoting identifiers.
# File lib/sequel/adapters/shared/mysql.rb, line 508 def quoted_identifier_append(sql, c) sql << BACKTICK << c.to_s << BACKTICK 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 520 def supports_distinct_on? true end
MySQL supports GROUP BY WITH ROLLUP (but not CUBE)
# File lib/sequel/adapters/shared/mysql.rb, line 525 def supports_group_rollup? true end
MySQL does not support INTERSECT or EXCEPT
# File lib/sequel/adapters/shared/mysql.rb, line 530 def supports_intersect_except? false end
MySQL supports modifying joined datasets
# File lib/sequel/adapters/shared/mysql.rb, line 535 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 541 def supports_ordered_distinct_on? false 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 548 def supports_timestamp_usecs? false end
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