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

mssql_unicode_strings[W]

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

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.

Calls superclass method
# 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
constant_sql_append(sql, constant) click to toggle source

MSSQL doesn't support the SQL standard CURRENT_DATE or CURRENT_TIME

Calls superclass method
# File lib/sequel/adapters/shared/mssql.rb, line 488
def constant_sql_append(sql, constant)
  if c = CONSTANT_MAP[constant]
    sql << c
  else
    super
  end
end
cross_apply(table) click to toggle source

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_insert_output() click to toggle source

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
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.

Calls superclass method
# 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
escape_like(string) click to toggle source

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
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 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
into(table) click to toggle source

Specify a table for a SELECT … INTO query.

# File lib/sequel/adapters/shared/mssql.rb, line 539
def into(table)
  clone(:into => table)
end
mssql_unicode_strings() click to toggle source

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
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 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
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 558
def nolock
  lock_style(:dirty)
end
outer_apply(table) click to toggle source

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
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 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
quoted_identifier_append(sql, name) click to toggle source

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
server_version() click to toggle source

The version of the database server.

# File lib/sequel/adapters/shared/mssql.rb, line 598
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 603
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 608
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 613
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 618
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 623
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 628
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 633
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 638
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 643
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 653
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 648
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.

Calls superclass method
# 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
aggregate_dataset() click to toggle source

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

Calls superclass method
# 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

default_timestamp_format() click to toggle source

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
delete_clause_methods() click to toggle source

MSSQL supports the OUTPUT clause for DELETE statements. It also allows prepending a WITH clause.

# File lib/sequel/adapters/shared/mssql.rb, line 702
def delete_clause_methods
  DELETE_CLAUSE_METHODS
end
delete_from2_sql(sql) click to toggle source

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
Also aliased as: update_from_sql
delete_from_sql(sql) click to toggle source

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
delete_output_sql(sql)
Alias for: output_sql
first_primary_key() click to toggle source

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
format_timestamp_usec(usec) click to toggle source

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
insert_clause_methods() click to toggle source

MSSQL supports the OUTPUT clause for INSERT statements. It also allows prepending a WITH clause.

# File lib/sequel/adapters/shared/mssql.rb, line 736
def insert_clause_methods
  INSERT_CLAUSE_METHODS
end
insert_output_sql(sql) click to toggle source

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
is_2005_or_later?() click to toggle source

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
is_2008_or_later?() click to toggle source

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
join_type_sql(join_type) click to toggle source

Handle CROSS APPLY and OUTER APPLY JOIN types

Calls superclass method
# 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
literal_blob_append(sql, v) click to toggle source

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
literal_date(v) click to toggle source

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
literal_false() click to toggle source

Use 0 for false on MSSQL

# File lib/sequel/adapters/shared/mssql.rb, line 774
def literal_false
  BOOL_FALSE
end
literal_string_append(sql, v) click to toggle source

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
literal_true() click to toggle source

Use 1 for true on MSSQL

# File lib/sequel/adapters/shared/mssql.rb, line 786
def literal_true
  BOOL_TRUE
end
output_sql(sql) click to toggle source

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
select_clause_methods() click to toggle source

MSSQL adds the limit before the columns

# File lib/sequel/adapters/shared/mssql.rb, line 791
def select_clause_methods
  SELECT_CLAUSE_METHODS
end
select_into_sql(sql) click to toggle source
# 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
select_limit_sql(sql) click to toggle source

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
Also aliased as: update_limit_sql
select_lock_sql(sql) click to toggle source

Support different types of locking styles

Calls superclass method
# 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
update_clause_methods() click to toggle source

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
update_from_sql(sql)
Alias for: delete_from2_sql
update_limit_sql(sql)
Alias for: select_limit_sql
update_output_sql(sql)
Alias for: output_sql
update_table_sql(sql) click to toggle source

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
uses_with_rollup?() click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 866
def uses_with_rollup?
  !is_2008_or_later?
end