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 666 def calc_found_rows clone(:calc_found_rows => true) end
# File lib/sequel/adapters/shared/mysql.rb, line 600 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' if !db.mariadb? && db.server_version >= 80000 && [:~, :'!~'].include?(op) func = Sequel.function(:REGEXP_LIKE, args[0], args[1], 'c') func = ~func if op == :'!~' return literal_append(sql, func) end 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 649 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 678 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 658 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 684 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] && (db.mariadb? || db.server_version < 50700)) ? '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 699 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 704 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 726 def insert_ignore clone(:insert_ignore=>true) end
Transforms :straight to STRAIGHT_JOIN.
# File lib/sequel/adapters/shared/mysql.rb, line 710 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 759 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 764 def quoted_identifier_append(sql, c) sql << '`' << c.to_s.gsub('`', '``') << '`' end
MariaDB 10.2+ and MySQL 8+ support CTEs
# File lib/sequel/adapters/shared/mysql.rb, line 769 def supports_cte?(type=:select) if db.mariadb? type == :select && db.server_version >= 100200 else case type when :select, :update, :delete db.server_version >= 80000 end end end
MySQL does not support derived column lists
# File lib/sequel/adapters/shared/mysql.rb, line 781 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 787 def supports_distinct_on? true end
MySQL supports GROUP BY WITH ROLLUP (but not CUBE)
# File lib/sequel/adapters/shared/mysql.rb, line 792 def supports_group_rollup? true end
MySQL does not support INTERSECT or EXCEPT
# File lib/sequel/adapters/shared/mysql.rb, line 797 def supports_intersect_except? false end
MySQL supports modifying joined datasets
# File lib/sequel/adapters/shared/mysql.rb, line 807 def supports_modifying_joins? true end
MySQL 8+ supports NOWAIT.
# File lib/sequel/adapters/shared/mysql.rb, line 812 def supports_nowait? !db.mariadb? && db.server_version >= 80000 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 818 def supports_ordered_distinct_on? false end
MySQL supports pattern matching via regular expressions
# File lib/sequel/adapters/shared/mysql.rb, line 823 def supports_regexp? true end
MySQL 8+ supports SKIP LOCKED.
# File lib/sequel/adapters/shared/mysql.rb, line 828 def supports_skip_locked? !db.mariadb? && db.server_version >= 80000 end
Check the database setting for whether fractional timestamps are suppported.
# File lib/sequel/adapters/shared/mysql.rb, line 834 def supports_timestamp_usecs? db.supports_timestamp_usecs? end
MariaDB 10.2+ and MySQL 8+ support window functions
# File lib/sequel/adapters/shared/mysql.rb, line 839 def supports_window_functions? db.server_version >= (db.mariadb? ? 100200 : 80000) 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 849 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 856 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 862 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 886 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 896 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 934 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 944 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 954 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 963 def literal_false '0' end
Raise error for infinitate and NaN values
# File lib/sequel/adapters/shared/mysql.rb, line 968 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 982 def literal_true '1' end
MySQL supports multiple rows in VALUES in INSERT.
# File lib/sequel/adapters/shared/mysql.rb, line 987 def multi_insert_sql_strategy :values end
# File lib/sequel/adapters/shared/mysql.rb, line 991 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 1025 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. Use SKIP LOCKED if skipping locked rows.
# File lib/sequel/adapters/shared/mysql.rb, line 1003 def select_lock_sql(sql) lock = @opts[:lock] if lock == :share if !db.mariadb? && db.server_version >= 80000 sql << ' FOR SHARE' else sql << ' LOCK IN SHARE MODE' end else super end if lock if @opts[:skip_locked] sql << " SKIP LOCKED" elsif @opts[:nowait] sql << " NOWAIT" end end end
# File lib/sequel/adapters/shared/mysql.rb, line 995 def select_only_offset_sql(sql) sql << " LIMIT " literal_append(sql, @opts[:offset]) sql << ",18446744073709551615" end
Use WITH RECURSIVE instead of WITH if any of the CTEs is recursive
# File lib/sequel/adapters/shared/mysql.rb, line 1030 def select_with_sql_base opts[:with].any?{|w| w[:recursive]} ? "WITH RECURSIVE " : super end
MySQL supports UPDATE IGNORE
# File lib/sequel/adapters/shared/mysql.rb, line 891 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 1035 def uses_with_rollup? true end