Allow overriding of the #mssql_unicode_strings option at the dataset level.
Copy the #mssql_unicode_strings
option from the db
object.
# File lib/sequel/adapters/shared/mssql.rb, line 444 def initialize(db, opts={}) super @mssql_unicode_strings = db.mssql_unicode_strings end
MSSQL uses + for string concatenation, and LIKE is case insensitive by default.
# File lib/sequel/adapters/shared/mssql.rb, line 450 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
Disable the use of INSERT OUTPUT
# File lib/sequel/adapters/shared/mssql.rb, line 488 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 501 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 493 def escape_like(string) string.gsub(%r[\\%_\[\]]/){|m| "\\#{m}"} end
MSSQL uses the CONTAINS keyword for full text search
# File lib/sequel/adapters/shared/mssql.rb, line 513 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 519 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 525 def into(table) clone(:into => table) end
MSSQL uses a UNION ALL statement to insert multiple values at once.
# File lib/sequel/adapters/shared/mssql.rb, line 530 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 544 def nolock lock_style(:dirty) 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 560 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
The version of the database server.
# File lib/sequel/adapters/shared/mssql.rb, line 580 def server_version db.server_version(@opts[:server]) end
MSSQL 2005+ supports GROUP BY CUBE.
# File lib/sequel/adapters/shared/mssql.rb, line 585 def supports_group_cube? is_2005_or_later? end
MSSQL 2005+ supports GROUP BY ROLLUP
# File lib/sequel/adapters/shared/mssql.rb, line 590 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 595 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 600 def supports_intersect_except? is_2005_or_later? end
MSSQL does not support IS TRUE
# File lib/sequel/adapters/shared/mssql.rb, line 605 def supports_is_true? false end
MSSQL doesn't support JOIN USING
# File lib/sequel/adapters/shared/mssql.rb, line 610 def supports_join_using? false end
MSSQL 2005+ supports modifying joined datasets
# File lib/sequel/adapters/shared/mssql.rb, line 615 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 620 def supports_multiple_column_in? false end
MSSQL 2005+ supports the output clause.
# File lib/sequel/adapters/shared/mssql.rb, line 625 def supports_output_clause? is_2005_or_later? end
MSSQL cannot use WHERE 1.
# File lib/sequel/adapters/shared/mssql.rb, line 635 def supports_where_true? false end
MSSQL 2005+ supports window functions
# File lib/sequel/adapters/shared/mssql.rb, line 630 def supports_window_functions? true end
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 645 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 659 def aggregate_dataset (options_overlap(Sequel::Dataset::COUNT_FROM_SELF_OPTS) && !options_overlap([:limit])) ? unordered.from_self : super end