module Sequel::MySQL::DatasetMethods
Dataset methods shared by datasets that use MySQL databases.
Constants
- MATCH_AGAINST
- MATCH_AGAINST_BOOLEAN
Public Instance Methods
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 614 def calc_found_rows clone(:calc_found_rows => true) end
# File lib/sequel/adapters/shared/mysql.rb, line 554 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 597 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 626 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 606 def distinct(*args) args.empty? ? super : group(*args) end
Return the results of an EXPLAIN query as a string. Options:
- :extended
-
Use EXPLAIN EXPTENDED instead of EXPLAIN if true.
# File lib/sequel/adapters/shared/mysql.rb, line 632 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 647 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 652 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 674 def insert_ignore clone(:insert_ignore=>true) end
Transforms :straight to STRAIGHT_JOIN.
# File lib/sequel/adapters/shared/mysql.rb, line 658 def join_type_sql(join_type) if join_type == :straight 'STRAIGHT_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 707 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 712 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 717 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 723 def supports_distinct_on? true end
MySQL supports GROUP BY WITH ROLLUP (but not CUBE)
# File lib/sequel/adapters/shared/mysql.rb, line 728 def supports_group_rollup? true end
MySQL does not support INTERSECT or EXCEPT
# File lib/sequel/adapters/shared/mysql.rb, line 733 def supports_intersect_except? false end
MySQL supports modifying joined datasets
# File lib/sequel/adapters/shared/mysql.rb, line 743 def supports_modifying_joins? true end
MySQL's DISTINCT ON emulation using GROUP BY does not respect the query's ORDER BY clause.
# File lib/sequel/adapters/shared/mysql.rb, line 749 def supports_ordered_distinct_on? false end
MySQL supports pattern matching via regular expressions
# File lib/sequel/adapters/shared/mysql.rb, line 754 def supports_regexp? true end
Check the database setting for whether fractional timestamps are suppported.
# File lib/sequel/adapters/shared/mysql.rb, line 760 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 770 def update_ignore clone(:update_ignore=>true) end
Private Instance Methods
Allow update and delete for limited datasets, unless there is an offset.
# File lib/sequel/adapters/shared/mysql.rb, line 777 def check_not_limited!(type) super if type == :truncate || @opts[:offset] end
Consider the first table in the joined dataset is the table to delete from, but include the others for the purposes of selecting rows.
# File lib/sequel/adapters/shared/mysql.rb, line 783 def delete_from_sql(sql) if joined_dataset? sql << ' ' tables = @opts[:delete_from] || @opts[:from][0..0] source_list_append(sql, tables) sql << ' FROM ' source_list_append(sql, @opts[:from]) select_join_sql(sql) else super end end
MySQL supports INSERT IGNORE INTO
# File lib/sequel/adapters/shared/mysql.rb, line 807 def insert_ignore_sql(sql) sql << " IGNORE" if opts[:insert_ignore] end
MySQL supports INSERT … ON DUPLICATE KEY UPDATE
# File lib/sequel/adapters/shared/mysql.rb, line 817 def insert_on_duplicate_key_update_sql(sql) if update_cols = opts[:on_duplicate_key_update] update_vals = nil if update_cols.empty? update_cols = columns elsif update_cols.last.is_a?(Hash) update_vals = update_cols.last update_cols = update_cols[0..-2] end sql << " ON DUPLICATE KEY UPDATE " c = false co = ', ' values = '=VALUES(' endp = ')' update_cols.each do |col| sql << co if c quote_identifier_append(sql, col) sql << values quote_identifier_append(sql, col) sql << endp c ||= true end if update_vals eq = '=' update_vals.map do |col,v| sql << co if c quote_identifier_append(sql, col) sql << eq literal_append(sql, v) c ||= true end end end end
MySQL doesn't use the standard DEFAULT VALUES for empty values.
# File lib/sequel/adapters/shared/mysql.rb, line 855 def insert_values_sql(sql) values = opts[:values] if values.is_a?(Array) && values.empty? sql << " VALUES ()" else super end end
MySQL allows a LIMIT in DELETE and UPDATE statements.
# File lib/sequel/adapters/shared/mysql.rb, line 865 def limit_sql(sql) if l = @opts[:limit] sql << " LIMIT " literal_append(sql, l) end end
MySQL uses a preceding X for hex escaping strings
# File lib/sequel/adapters/shared/mysql.rb, line 875 def literal_blob_append(sql, v) if v.empty? sql << "''" else sql << "0x" << v.unpack("H*").first end end
Use 0 for false on MySQL
# File lib/sequel/adapters/shared/mysql.rb, line 884 def literal_false '0' end
Raise error for infinitate and NaN values
# File lib/sequel/adapters/shared/mysql.rb, line 889 def literal_float(v) if v.infinite? || v.nan? raise InvalidValue, "Infinite floats and NaN values are not valid on MySQL" else super end end
Use 1 for true on MySQL
# File lib/sequel/adapters/shared/mysql.rb, line 903 def literal_true '1' end
MySQL supports multiple rows in VALUES in INSERT.
# File lib/sequel/adapters/shared/mysql.rb, line 908 def multi_insert_sql_strategy :values end
# File lib/sequel/adapters/shared/mysql.rb, line 912 def non_sql_option?(key) super || key == :insert_ignore || key == :update_ignore || key == :on_duplicate_key_update end
MySQL specific SQL_CALC_FOUND_ROWS option
# File lib/sequel/adapters/shared/mysql.rb, line 928 def select_calc_found_rows_sql(sql) sql << ' SQL_CALC_FOUND_ROWS' if opts[:calc_found_rows] end
Support FOR SHARE locking when using the :share lock style.
# File lib/sequel/adapters/shared/mysql.rb, line 923 def select_lock_sql(sql) @opts[:lock] == :share ? (sql << ' LOCK IN SHARE MODE') : super end
# File lib/sequel/adapters/shared/mysql.rb, line 916 def select_only_offset_sql(sql) sql << " LIMIT " literal_append(sql, @opts[:offset]) sql << ",18446744073709551615" end
MySQL supports UPDATE IGNORE
# File lib/sequel/adapters/shared/mysql.rb, line 812 def update_ignore_sql(sql) sql << " IGNORE" if opts[:update_ignore] end
MySQL uses WITH ROLLUP syntax.
# File lib/sequel/adapters/shared/mysql.rb, line 933 def uses_with_rollup? true end