module Sequel::MSSQL::DatasetMethods
Constants
- APOS
- APOS_RE
- BACKSLASH_CRLF_RE
- BACKSLASH_CRLF_REPLACE
- BOOL_FALSE
- BOOL_TRUE
- BRACKET_CLOSE
- BRACKET_OPEN
- CASE_INSENSITIVE_COLLATION
- CASE_SENSITIVE_COLLATION
- COMMA
- COMMA_SEPARATOR
- CONSTANT_MAP
- CROSS_APPLY
- DATEPART_OPEN
- DATEPART_SECOND_CLOSE
- DATEPART_SECOND_MIDDLE
- DATEPART_SECOND_OPEN
- DEFAULT_TIMESTAMP_FORMAT
- DELETE_CLAUSE_METHODS
- DOUBLE_APOS
- DOUBLE_BRACKET_CLOSE
- EXTRACT_MAP
- FORMAT_DATE
- FROM
- HEX_START
- HSTAR
- INSERT_CLAUSE_METHODS
- INTO
- NOLOCK
- OUTER_APPLY
- OUTPUT
- OUTPUT_INSERTED
- PAREN_CLOSE
- PAREN_SPACE_OPEN
- SELECT_CLAUSE_METHODS
- SELECT_SPACE
- SPACE
- TIMESTAMP_USEC_FORMAT
- TOP
- TOP_PAREN
- UNICODE_STRING_START
- UNION_ALL
- UPDATE_CLAUSE_METHODS
- UPDATE_CLAUSE_METHODS_2000
- UPDLOCK
- WILDCARD
Attributes
Allow overriding of the #mssql_unicode_strings option at the dataset level.
Public Instance Methods
MSSQL uses + for string concatenation, and LIKE is case insensitive by default.
# File lib/sequel/adapters/shared/mssql.rb, line 459 def complex_expression_sql_append(sql, op, args) case op when :'||' super(sql, :+, args) when :LIKE, :"NOT LIKE" super(sql, op, args.map{|a| LiteralString.new("(#{literal(a)} COLLATE #{CASE_SENSITIVE_COLLATION})")}) when :ILIKE, :"NOT ILIKE" super(sql, (op == :ILIKE ? :LIKE : :"NOT LIKE"), args.map{|a| LiteralString.new("(#{literal(a)} COLLATE #{CASE_INSENSITIVE_COLLATION})")}) when :<< sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} * POWER(2, #{literal(b)}))"} when :>> sql << complex_expression_arg_pairs(args){|a, b| "(#{literal(a)} / POWER(2, #{literal(b)}))"} when :extract part = args.at(0) raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part] if part == :second expr = literal(args.at(1)) sql << DATEPART_SECOND_OPEN << format.to_s << COMMA << expr << DATEPART_SECOND_MIDDLE << expr << DATEPART_SECOND_CLOSE else sql << DATEPART_OPEN << format.to_s << COMMA literal_append(sql, args.at(1)) sql << PAREN_CLOSE end else super end end
Uses CROSS APPLY to join the given table into the current dataset.
# File lib/sequel/adapters/shared/mssql.rb, line 497 def cross_apply(table) join_table(:cross_apply, table) end
Disable the use of INSERT OUTPUT
# File lib/sequel/adapters/shared/mssql.rb, line 502 def disable_insert_output clone(:disable_insert_output=>true) end
There is no function on Microsoft SQL Server that does character length and respects trailing spaces (datalength respects trailing spaces, but counts bytes instead of characters). Use a hack to work around the trailing spaces issue.
# File lib/sequel/adapters/shared/mssql.rb, line 515 def emulated_function_sql_append(sql, f) case f.f when :char_length literal_append(sql, SQL::Function.new(:len, Sequel.join([f.args.first, 'x'])) - 1) when :trim literal_append(sql, SQL::Function.new(:ltrim, SQL::Function.new(:rtrim, f.args.first))) else super end end
MSSQL treats [] as a metacharacter in LIKE expresions.
# File lib/sequel/adapters/shared/mssql.rb, line 507 def escape_like(string) string.gsub(/[\%_\[\]]/){|m| "\\#{m}"} end
MSSQL uses the CONTAINS keyword for full text search
# File lib/sequel/adapters/shared/mssql.rb, line 527 def full_text_search(cols, terms, opts = {}) terms = "\"#{terms.join('" OR "')}\"" if terms.is_a?(Array) filter("CONTAINS (?, ?)", cols, terms) end
Use the OUTPUT clause to get the value of all columns for the newly inserted record.
# File lib/sequel/adapters/shared/mssql.rb, line 533 def insert_select(*values) return unless supports_insert_select? naked.clone(default_server_opts(:sql=>output(nil, [SQL::ColumnAll.new(:inserted)]).insert_sql(*values))).single_record end
Specify a table for a SELECT … INTO query.
# File lib/sequel/adapters/shared/mssql.rb, line 539 def into(table) clone(:into => table) end
Use the database's #mssql_unicode_strings setting if the dataset hasn't overridden it.
# File lib/sequel/adapters/shared/mssql.rb, line 454 def mssql_unicode_strings defined?(@mssql_unicode_strings) ? @mssql_unicode_strings : (@mssql_unicode_strings = db.mssql_unicode_strings) end
MSSQL uses a UNION ALL statement to insert multiple values at once.
# File lib/sequel/adapters/shared/mssql.rb, line 544 def multi_insert_sql(columns, values) c = false sql = LiteralString.new('') u = UNION_ALL values.each do |v| sql << u if c sql << SELECT_SPACE expression_list_append(sql, v) c ||= true end [insert_sql(columns, sql)] end
Allows you to do a dirty read of uncommitted data using WITH (NOLOCK).
# File lib/sequel/adapters/shared/mssql.rb, line 558 def nolock lock_style(:dirty) end
Uses OUTER APPLY to join the given table into the current dataset.
# File lib/sequel/adapters/shared/mssql.rb, line 563 def outer_apply(table) join_table(:outer_apply, table) end
Include an OUTPUT clause in the eventual INSERT, UPDATE, or DELETE query.
The first argument is the table to output into, and the second argument is either an Array of column values to select, or a Hash which maps output column names to selected values, in the style of insert or update.
Output into a returned result set is not currently supported.
Examples:
dataset.output(:output_table, [:deleted__id, :deleted__name]) dataset.output(:output_table, :id => :inserted__id, :name => :inserted__name)
# File lib/sequel/adapters/shared/mssql.rb, line 579 def output(into, values) raise(Error, "SQL Server versions 2000 and earlier do not support the OUTPUT clause") unless supports_output_clause? output = {} case values when Hash output[:column_list], output[:select_list] = values.keys, values.values when Array output[:select_list] = values end output[:into] = into clone({:output => output}) end
MSSQL uses [] to quote identifiers.
# File lib/sequel/adapters/shared/mssql.rb, line 593 def quoted_identifier_append(sql, name) sql << BRACKET_OPEN << name.to_s.gsub(/\]/, DOUBLE_BRACKET_CLOSE) << BRACKET_CLOSE end
The version of the database server.
# File lib/sequel/adapters/shared/mssql.rb, line 598 def server_version db.server_version(@opts[:server]) end
MSSQL 2005+ supports GROUP BY CUBE.
# File lib/sequel/adapters/shared/mssql.rb, line 603 def supports_group_cube? is_2005_or_later? end
MSSQL 2005+ supports GROUP BY ROLLUP
# File lib/sequel/adapters/shared/mssql.rb, line 608 def supports_group_rollup? is_2005_or_later? end
MSSQL supports #insert_select via the OUTPUT clause.
# File lib/sequel/adapters/shared/mssql.rb, line 613 def supports_insert_select? supports_output_clause? && !opts[:disable_insert_output] end
MSSQL 2005+ supports INTERSECT and EXCEPT
# File lib/sequel/adapters/shared/mssql.rb, line 618 def supports_intersect_except? is_2005_or_later? end
MSSQL does not support IS TRUE
# File lib/sequel/adapters/shared/mssql.rb, line 623 def supports_is_true? false end
MSSQL doesn't support JOIN USING
# File lib/sequel/adapters/shared/mssql.rb, line 628 def supports_join_using? false end
MSSQL 2005+ supports modifying joined datasets
# File lib/sequel/adapters/shared/mssql.rb, line 633 def supports_modifying_joins? is_2005_or_later? end
MSSQL does not support multiple columns for the IN/NOT IN operators
# File lib/sequel/adapters/shared/mssql.rb, line 638 def supports_multiple_column_in? false end
MSSQL 2005+ supports the output clause.
# File lib/sequel/adapters/shared/mssql.rb, line 643 def supports_output_clause? is_2005_or_later? end
MSSQL cannot use WHERE 1.
# File lib/sequel/adapters/shared/mssql.rb, line 653 def supports_where_true? false end
MSSQL 2005+ supports window functions
# File lib/sequel/adapters/shared/mssql.rb, line 648 def supports_window_functions? true end
Protected Instance Methods
If returned primary keys are requested, use OUTPUT unless already set on the dataset. If OUTPUT is already set, use existing returning values. If OUTPUT is only set to return a single columns, return an array of just that column. Otherwise, return an array of hashes.
# File lib/sequel/adapters/shared/mssql.rb, line 663 def _import(columns, values, opts={}) if opts[:return] == :primary_key && !@opts[:output] output(nil, [SQL::QualifiedIdentifier.new(:inserted, first_primary_key)])._import(columns, values, opts) elsif @opts[:output] statements = multi_insert_sql(columns, values) @db.transaction(opts.merge(:server=>@opts[:server])) do statements.map{|st| with_sql(st)} end.first.map{|v| v.length == 1 ? v.values.first : v} else super end end
MSSQL does not allow ordering in sub-clauses unless 'top' (limit) is specified
# File lib/sequel/adapters/shared/mssql.rb, line 677 def aggregate_dataset (options_overlap(Sequel::Dataset::COUNT_FROM_SELF_OPTS) && !options_overlap([:limit])) ? unordered.from_self : super end
Private Instance Methods
Use strict ISO-8601 format with T between date and time, since that is the format that is multilanguage and not DATEFORMAT dependent.
# File lib/sequel/adapters/shared/mssql.rb, line 696 def default_timestamp_format DEFAULT_TIMESTAMP_FORMAT end
MSSQL supports FROM clauses in DELETE and UPDATE statements.
# File lib/sequel/adapters/shared/mssql.rb, line 713 def delete_from2_sql(sql) if joined_dataset? select_from_sql(sql) select_join_sql(sql) end end
Only include the primary table in the main delete clause
# File lib/sequel/adapters/shared/mssql.rb, line 707 def delete_from_sql(sql) sql << FROM source_list_append(sql, @opts[:from][0..0]) end
Return the first primary key for the current table. If this table has multiple primary keys, this will only return one of them. Used by #_import.
# File lib/sequel/adapters/shared/mssql.rb, line 723 def first_primary_key @db.schema(self).map{|k, v| k if v[:primary_key] == true}.compact.first end
MSSQL raises an error if you try to provide more than 3 decimal places for a fractional timestamp. This probably doesn't work for smalldatetime fields.
# File lib/sequel/adapters/shared/mssql.rb, line 730 def format_timestamp_usec(usec) sprintf(TIMESTAMP_USEC_FORMAT, usec/1000) end
Use OUTPUT INSERTED.* to return all columns of the inserted row, for use with the prepared statement code.
# File lib/sequel/adapters/shared/mssql.rb, line 742 def insert_output_sql(sql) if @opts.has_key?(:returning) sql << OUTPUT_INSERTED else output_sql(sql) end end
Whether we are using SQL Server 2005 or later.
# File lib/sequel/adapters/shared/mssql.rb, line 684 def is_2005_or_later? server_version >= 9000000 end
Whether we are using SQL Server 2008 or later.
# File lib/sequel/adapters/shared/mssql.rb, line 689 def is_2008_or_later? server_version >= 10000000 end
Handle CROSS APPLY and OUTER APPLY JOIN types
# File lib/sequel/adapters/shared/mssql.rb, line 751 def join_type_sql(join_type) case join_type when :cross_apply CROSS_APPLY when :outer_apply OUTER_APPLY else super end end
MSSQL uses a literal hexidecimal number for blob strings
# File lib/sequel/adapters/shared/mssql.rb, line 763 def literal_blob_append(sql, v) sql << HEX_START << v.unpack(HSTAR).first end
Use YYYYmmdd format, since that's the only want that is multilanguage and not DATEFORMAT dependent.
# File lib/sequel/adapters/shared/mssql.rb, line 769 def literal_date(v) v.strftime(FORMAT_DATE) end
Use 0 for false on MSSQL
# File lib/sequel/adapters/shared/mssql.rb, line 774 def literal_false BOOL_FALSE end
Optionally use unicode string syntax for all strings. Don't double backslashes.
# File lib/sequel/adapters/shared/mssql.rb, line 780 def literal_string_append(sql, v) sql << (mssql_unicode_strings ? UNICODE_STRING_START : APOS) sql << v.gsub(APOS_RE, DOUBLE_APOS).gsub(BACKSLASH_CRLF_RE, BACKSLASH_CRLF_REPLACE) << APOS end
Use 1 for true on MSSQL
# File lib/sequel/adapters/shared/mssql.rb, line 786 def literal_true BOOL_TRUE end
SQL fragment for MSSQL's OUTPUT clause.
# File lib/sequel/adapters/shared/mssql.rb, line 831 def output_sql(sql) return unless supports_output_clause? return unless output = @opts[:output] sql << OUTPUT column_list_append(sql, output[:select_list]) if into = output[:into] sql << INTO identifier_append(sql, into) if column_list = output[:column_list] sql << PAREN_SPACE_OPEN source_list_append(sql, column_list) sql << PAREN_CLOSE end end end
MSSQL adds the limit before the columns
# File lib/sequel/adapters/shared/mssql.rb, line 791 def select_clause_methods SELECT_CLAUSE_METHODS end
# File lib/sequel/adapters/shared/mssql.rb, line 795 def select_into_sql(sql) if i = @opts[:into] sql << INTO identifier_append(sql, i) end end
MSSQL uses TOP N for limit. For MSSQL 2005+ TOP (N) is used to allow the limit to be a bound variable.
# File lib/sequel/adapters/shared/mssql.rb, line 804 def select_limit_sql(sql) if l = @opts[:limit] if is_2005_or_later? sql << TOP_PAREN literal_append(sql, l) sql << PAREN_CLOSE else sql << TOP literal_append(sql, l) end end end
Support different types of locking styles
# File lib/sequel/adapters/shared/mssql.rb, line 819 def select_lock_sql(sql) case @opts[:lock] when :update sql << UPDLOCK when :dirty sql << NOLOCK else super end end
MSSQL supports the OUTPUT and TOP clause for UPDATE statements. It also allows prepending a WITH clause. For MSSQL 2000 and below, exclude WITH and TOP.
# File lib/sequel/adapters/shared/mssql.rb, line 852 def update_clause_methods if is_2005_or_later? UPDATE_CLAUSE_METHODS else UPDATE_CLAUSE_METHODS_2000 end end
Only include the primary table in the main update clause
# File lib/sequel/adapters/shared/mssql.rb, line 861 def update_table_sql(sql) sql << SPACE source_list_append(sql, @opts[:from][0..0]) end
# File lib/sequel/adapters/shared/mssql.rb, line 866 def uses_with_rollup? !is_2008_or_later? end