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
DATEPART_OPEN
DATEPART_SECOND_CLOSE
DATEPART_SECOND_MIDDLE
DATEPART_SECOND_OPEN
DEFAULT_TIMESTAMP_FORMAT
DELETE_CLAUSE_METHODS
DOUBLE_APOS
EXTRACT_MAP
FORMAT_DATE
FROM
HEX_START
HSTAR
INSERT_CLAUSE_METHODS
INTO
NOLOCK
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

mssql_unicode_strings[RW]

Allow overriding of the #mssql_unicode_strings option at the dataset level.

Public Class Methods

new(db, opts={}) click to toggle source

Copy the #mssql_unicode_strings option from the db object.

# File lib/sequel/adapters/shared/mssql.rb, line 429
def initialize(db, opts={})
  super
  @mssql_unicode_strings = db.mssql_unicode_strings
end

Public Instance Methods

complex_expression_sql_append(sql, op, args) click to toggle source

MSSQL uses + for string concatenation, and LIKE is case insensitive by default.

# File lib/sequel/adapters/shared/mssql.rb, line 435
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
constant_sql_append(sql, constant) click to toggle source

MSSQL doesn't support the SQL standard CURRENT_DATE or CURRENT_TIME

# File lib/sequel/adapters/shared/mssql.rb, line 464
def constant_sql_append(sql, constant)
  if c = CONSTANT_MAP[constant]
    sql << c
  else
    super
  end
end
disable_insert_output() click to toggle source

Disable the use of INSERT OUTPUT

# File lib/sequel/adapters/shared/mssql.rb, line 473
def disable_insert_output
  clone(:disable_insert_output=>true)
end
disable_insert_output!() click to toggle source

Disable the use of INSERT OUTPUT, modifying the receiver

# File lib/sequel/adapters/shared/mssql.rb, line 478
def disable_insert_output!
  mutation_method(:disable_insert_output)
end
emulated_function_sql_append(sql, f) click to toggle source

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 486
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
insert_select(*values) click to toggle source

Use the OUTPUT clause to get the value of all columns for the newly inserted record.

# File lib/sequel/adapters/shared/mssql.rb, line 504
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
into(table) click to toggle source

Specify a table for a SELECT ... INTO query.

# File lib/sequel/adapters/shared/mssql.rb, line 510
def into(table)
  clone(:into => table)
end
multi_insert_sql(columns, values) click to toggle source

MSSQL uses a UNION ALL statement to insert multiple values at once.

# File lib/sequel/adapters/shared/mssql.rb, line 515
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
nolock() click to toggle source

Allows you to do a dirty read of uncommitted data using WITH (NOLOCK).

# File lib/sequel/adapters/shared/mssql.rb, line 529
def nolock
  lock_style(:dirty)
end
output(into, values) click to toggle source

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 545
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
output!(into, values) click to toggle source

An output method that modifies the receiver.

# File lib/sequel/adapters/shared/mssql.rb, line 559
def output!(into, values)
  mutation_method(:output, into, values)
end
quoted_identifier_append(sql, name) click to toggle source

MSSQL uses [] to quote identifiers. MSSQL does not support escaping of ], so you cannot use that character in an identifier.

# File lib/sequel/adapters/shared/mssql.rb, line 565
def quoted_identifier_append(sql, name)
  sql << BRACKET_OPEN << name.to_s << BRACKET_CLOSE
end
server_version() click to toggle source

The version of the database server.

# File lib/sequel/adapters/shared/mssql.rb, line 570
def server_version
  db.server_version(@opts[:server])
end
supports_group_cube?() click to toggle source

MSSQL 2005+ supports GROUP BY CUBE.

# File lib/sequel/adapters/shared/mssql.rb, line 575
def supports_group_cube?
  is_2005_or_later?
end
supports_group_rollup?() click to toggle source

MSSQL 2005+ supports GROUP BY ROLLUP

# File lib/sequel/adapters/shared/mssql.rb, line 580
def supports_group_rollup?
  is_2005_or_later?
end
supports_insert_select?() click to toggle source

MSSQL supports #insert_select via the OUTPUT clause.

# File lib/sequel/adapters/shared/mssql.rb, line 585
def supports_insert_select?
  supports_output_clause? && !opts[:disable_insert_output]
end
supports_intersect_except?() click to toggle source

MSSQL 2005+ supports INTERSECT and EXCEPT

# File lib/sequel/adapters/shared/mssql.rb, line 590
def supports_intersect_except?
  is_2005_or_later?
end
supports_is_true?() click to toggle source

MSSQL does not support IS TRUE

# File lib/sequel/adapters/shared/mssql.rb, line 595
def supports_is_true?
  false
end
supports_join_using?() click to toggle source

MSSQL doesn't support JOIN USING

# File lib/sequel/adapters/shared/mssql.rb, line 600
def supports_join_using?
  false
end
supports_modifying_joins?() click to toggle source

MSSQL 2005+ supports modifying joined datasets

# File lib/sequel/adapters/shared/mssql.rb, line 605
def supports_modifying_joins?
  is_2005_or_later?
end
supports_multiple_column_in?() click to toggle source

MSSQL does not support multiple columns for the IN/NOT IN operators

# File lib/sequel/adapters/shared/mssql.rb, line 610
def supports_multiple_column_in?
  false
end
supports_output_clause?() click to toggle source

MSSQL 2005+ supports the output clause.

# File lib/sequel/adapters/shared/mssql.rb, line 615
def supports_output_clause?
  is_2005_or_later?
end
supports_where_true?() click to toggle source

MSSQL cannot use WHERE 1.

# File lib/sequel/adapters/shared/mssql.rb, line 625
def supports_where_true?
  false
end
supports_window_functions?() click to toggle source

MSSQL 2005+ supports window functions

# File lib/sequel/adapters/shared/mssql.rb, line 620
def supports_window_functions?
  true
end

Protected Instance Methods

_import(columns, values, opts={}) click to toggle source

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 635
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
aggregate_dataset() click to toggle source

MSSQL does not allow ordering in sub-clauses unless 'top' (limit) is specified

# File lib/sequel/adapters/shared/mssql.rb, line 649
def aggregate_dataset
  (options_overlap(Sequel::Dataset::COUNT_FROM_SELF_OPTS) && !options_overlap([:limit])) ? unordered.from_self : super
end