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 677 def calc_found_rows 678 clone(:calc_found_rows => true) 679 end
# File lib/sequel/adapters/shared/mysql.rb 611 def complex_expression_sql_append(sql, op, args) 612 case op 613 when :IN, :"NOT IN" 614 ds = args[1] 615 if ds.is_a?(Sequel::Dataset) && ds.opts[:limit] 616 super(sql, op, [args[0], ds.from_self]) 617 else 618 super 619 end 620 when :~, :'!~', :'~*', :'!~*', :LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE' 621 if !db.mariadb? && db.server_version >= 80000 && [:~, :'!~'].include?(op) 622 func = Sequel.function(:REGEXP_LIKE, args[0], args[1], 'c') 623 func = ~func if op == :'!~' 624 return literal_append(sql, func) 625 end 626 627 sql << '(' 628 literal_append(sql, args[0]) 629 sql << ' ' 630 sql << 'NOT ' if [:'NOT LIKE', :'NOT ILIKE', :'!~', :'!~*'].include?(op) 631 sql << ([:~, :'!~', :'~*', :'!~*'].include?(op) ? 'REGEXP' : 'LIKE') 632 sql << ' ' 633 sql << 'BINARY ' if [:~, :'!~', :LIKE, :'NOT LIKE'].include?(op) 634 literal_append(sql, args[1]) 635 if [:LIKE, :'NOT LIKE', :ILIKE, :'NOT ILIKE'].include?(op) 636 sql << " ESCAPE " 637 literal_append(sql, "\\") 638 end 639 sql << ')' 640 when :'||' 641 if args.length > 1 642 sql << "CONCAT" 643 array_sql_append(sql, args) 644 else 645 literal_append(sql, args[0]) 646 end 647 when :'B~' 648 sql << "CAST(~" 649 literal_append(sql, args[0]) 650 sql << " AS SIGNED INTEGER)" 651 else 652 super 653 end 654 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 660 def constant_sql_append(sql, constant) 661 if constant == :CURRENT_TIMESTAMP && supports_timestamp_usecs? 662 sql << 'CURRENT_TIMESTAMP(6)' 663 else 664 super 665 end 666 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 689 def delete_from(*tables) 690 clone(:delete_from=>tables) 691 end
Use GROUP BY instead of DISTINCT ON if arguments are provided.
# File lib/sequel/adapters/shared/mysql.rb 669 def distinct(*args) 670 args.empty? ? super : group(*args) 671 end
Return the results of an EXPLAIN query as a string. Options:
- :extended
-
Use EXPLAIN EXTENDED instead of EXPLAIN if true.
# File lib/sequel/adapters/shared/mysql.rb 695 def explain(opts=OPTS) 696 # Load the PrettyTable class, needed for explain output 697 Sequel.extension(:_pretty_table) unless defined?(Sequel::PrettyTable) 698 699 ds = db.send(:metadata_dataset).with_sql(((opts[:extended] && (db.mariadb? || db.server_version < 50700)) ? 'EXPLAIN EXTENDED ' : 'EXPLAIN ') + select_sql).naked 700 rows = ds.all 701 Sequel::PrettyTable.string(rows, ds.columns) 702 end
Adds full text filter
# File lib/sequel/adapters/shared/mysql.rb 710 def full_text_search(cols, terms, opts = OPTS) 711 where(full_text_sql(cols, terms, opts)) 712 end
MySQL
specific full text search syntax.
# File lib/sequel/adapters/shared/mysql.rb 715 def full_text_sql(cols, terms, opts = OPTS) 716 terms = terms.join(' ') if terms.is_a?(Array) 717 SQL::PlaceholderLiteralString.new((opts[:boolean] ? MATCH_AGAINST_BOOLEAN : MATCH_AGAINST), [Array(cols), terms]) 718 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 728 def insert_ignore 729 clone(:insert_ignore=>true) 730 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 761 def on_duplicate_key_update(*args) 762 clone(:on_duplicate_key_update => args) 763 end
MySQL
uses the nonstandard ` (backtick) for quoting identifiers.
# File lib/sequel/adapters/shared/mysql.rb 766 def quoted_identifier_append(sql, c) 767 sql << '`' << c.to_s.gsub('`', '``') << '`' 768 end
MariaDB 10.2+ and MySQL
8+ support CTEs
# File lib/sequel/adapters/shared/mysql.rb 771 def supports_cte?(type=:select) 772 if db.mariadb? 773 type == :select && db.server_version >= 100200 774 else 775 case type 776 when :select, :update, :delete 777 db.server_version >= 80000 778 end 779 end 780 end
MySQL
does not support derived column lists
# File lib/sequel/adapters/shared/mysql.rb 783 def supports_derived_column_lists? 784 false 785 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 789 def supports_distinct_on? 790 true 791 end
MySQL
supports GROUP BY WITH ROLLUP (but not CUBE)
# File lib/sequel/adapters/shared/mysql.rb 794 def supports_group_rollup? 795 true 796 end
MariaDB 10.3+ supports INTERSECT or EXCEPT
# File lib/sequel/adapters/shared/mysql.rb 799 def supports_intersect_except? 800 db.mariadb? && db.server_version >= 100300 801 end
MySQL
supports modifying joined datasets
# File lib/sequel/adapters/shared/mysql.rb 809 def supports_modifying_joins? 810 true 811 end
MySQL
8+ and MariaDB 10.3+ support NOWAIT.
# File lib/sequel/adapters/shared/mysql.rb 814 def supports_nowait? 815 db.server_version >= (db.mariadb? ? 100300 : 80000) 816 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 820 def supports_ordered_distinct_on? 821 false 822 end
MySQL
supports pattern matching via regular expressions
# File lib/sequel/adapters/shared/mysql.rb 825 def supports_regexp? 826 true 827 end
MySQL
8+ supports SKIP LOCKED.
# File lib/sequel/adapters/shared/mysql.rb 830 def supports_skip_locked? 831 !db.mariadb? && db.server_version >= 80000 832 end
Check the database setting for whether fractional timestamps are suppported.
# File lib/sequel/adapters/shared/mysql.rb 836 def supports_timestamp_usecs? 837 db.supports_timestamp_usecs? 838 end
MySQL
8+ supports WINDOW clause.
# File lib/sequel/adapters/shared/mysql.rb 841 def supports_window_clause? 842 !db.mariadb? && db.server_version >= 80000 843 end
MariaDB 10.2+ and MySQL
8+ support window functions
# File lib/sequel/adapters/shared/mysql.rb 846 def supports_window_functions? 847 db.server_version >= (db.mariadb? ? 100200 : 80000) 848 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 856 def update_ignore 857 clone(:update_ignore=>true) 858 end
Private Instance Methods
Allow update and delete for limited datasets, unless there is an offset.
# File lib/sequel/adapters/shared/mysql.rb 863 def check_not_limited!(type) 864 super if type == :truncate || @opts[:offset] 865 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 869 def delete_from_sql(sql) 870 if joined_dataset? 871 sql << ' ' 872 tables = @opts[:delete_from] || @opts[:from][0..0] 873 source_list_append(sql, tables) 874 sql << ' FROM ' 875 source_list_append(sql, @opts[:from]) 876 select_join_sql(sql) 877 else 878 super 879 end 880 end
MySQL
supports INSERT IGNORE INTO
# File lib/sequel/adapters/shared/mysql.rb 893 def insert_ignore_sql(sql) 894 sql << " IGNORE" if opts[:insert_ignore] 895 end
MySQL
supports INSERT … ON DUPLICATE KEY UPDATE
# File lib/sequel/adapters/shared/mysql.rb 903 def insert_on_duplicate_key_update_sql(sql) 904 if update_cols = opts[:on_duplicate_key_update] 905 update_vals = nil 906 907 if update_cols.empty? 908 update_cols = columns 909 elsif update_cols.last.is_a?(Hash) 910 update_vals = update_cols.last 911 update_cols = update_cols[0..-2] 912 end 913 914 sql << " ON DUPLICATE KEY UPDATE " 915 c = false 916 co = ', ' 917 values = '=VALUES(' 918 endp = ')' 919 update_cols.each do |col| 920 sql << co if c 921 quote_identifier_append(sql, col) 922 sql << values 923 quote_identifier_append(sql, col) 924 sql << endp 925 c ||= true 926 end 927 if update_vals 928 eq = '=' 929 update_vals.map do |col,v| 930 sql << co if c 931 quote_identifier_append(sql, col) 932 sql << eq 933 literal_append(sql, v) 934 c ||= true 935 end 936 end 937 end 938 end
MySQL
doesn't use the standard DEFAULT VALUES for empty values.
# File lib/sequel/adapters/shared/mysql.rb 941 def insert_values_sql(sql) 942 values = opts[:values] 943 if values.is_a?(Array) && values.empty? 944 sql << " VALUES ()" 945 else 946 super 947 end 948 end
Transforms :straight to STRAIGHT_JOIN.
# File lib/sequel/adapters/shared/mysql.rb 951 def join_type_sql(join_type) 952 if join_type == :straight 953 'STRAIGHT_JOIN' 954 else 955 super 956 end 957 end
MySQL
allows a LIMIT in DELETE and UPDATE statements.
# File lib/sequel/adapters/shared/mysql.rb 960 def limit_sql(sql) 961 if l = @opts[:limit] 962 sql << " LIMIT " 963 literal_append(sql, l) 964 end 965 end
MySQL
uses a preceding X for hex escaping strings
# File lib/sequel/adapters/shared/mysql.rb 970 def literal_blob_append(sql, v) 971 if v.empty? 972 sql << "''" 973 else 974 sql << "0x" << v.unpack("H*").first 975 end 976 end
Use 0 for false on MySQL
# File lib/sequel/adapters/shared/mysql.rb 979 def literal_false 980 '0' 981 end
Raise error for infinitate and NaN values
# File lib/sequel/adapters/shared/mysql.rb 984 def literal_float(v) 985 if v.infinite? || v.nan? 986 raise InvalidValue, "Infinite floats and NaN values are not valid on MySQL" 987 else 988 super 989 end 990 end
Use 1 for true on MySQL
# File lib/sequel/adapters/shared/mysql.rb 998 def literal_true 999 '1' 1000 end
MySQL
supports multiple rows in VALUES in INSERT.
# File lib/sequel/adapters/shared/mysql.rb 1003 def multi_insert_sql_strategy 1004 :values 1005 end
# File lib/sequel/adapters/shared/mysql.rb 1007 def non_sql_option?(key) 1008 super || key == :insert_ignore || key == :update_ignore || key == :on_duplicate_key_update 1009 end
MySQL
does not natively support NULLS FIRST/LAST.
# File lib/sequel/adapters/shared/mysql.rb 1012 def requires_emulating_nulls_first? 1013 true 1014 end
MySQL
specific SQL_CALC_FOUND_ROWS option
# File lib/sequel/adapters/shared/mysql.rb 1046 def select_calc_found_rows_sql(sql) 1047 sql << ' SQL_CALC_FOUND_ROWS' if opts[:calc_found_rows] 1048 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 1024 def select_lock_sql(sql) 1025 lock = @opts[:lock] 1026 if lock == :share 1027 if !db.mariadb? && db.server_version >= 80000 1028 sql << ' FOR SHARE' 1029 else 1030 sql << ' LOCK IN SHARE MODE' 1031 end 1032 else 1033 super 1034 end 1035 1036 if lock 1037 if @opts[:skip_locked] 1038 sql << " SKIP LOCKED" 1039 elsif @opts[:nowait] 1040 sql << " NOWAIT" 1041 end 1042 end 1043 end
# File lib/sequel/adapters/shared/mysql.rb 1016 def select_only_offset_sql(sql) 1017 sql << " LIMIT " 1018 literal_append(sql, @opts[:offset]) 1019 sql << ",18446744073709551615" 1020 end
Use WITH RECURSIVE instead of WITH if any of the CTEs is recursive
# File lib/sequel/adapters/shared/mysql.rb 1051 def select_with_sql_base 1052 opts[:with].any?{|w| w[:recursive]} ? "WITH RECURSIVE " : super 1053 end
MySQL
supports UPDATE IGNORE
# File lib/sequel/adapters/shared/mysql.rb 898 def update_ignore_sql(sql) 899 sql << " IGNORE" if opts[:update_ignore] 900 end
MySQL
uses WITH ROLLUP syntax.
# File lib/sequel/adapters/shared/mysql.rb 1056 def uses_with_rollup? 1057 true 1058 end