module Sequel::MSSQL

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
DOUBLE_APOS
DOUBLE_BRACKET_CLOSE
EXTRACT_MAP
FETCH_NEXT
FORMAT_DATE
FROM
HEX_START
HSTAR
INTO
NOLOCK
OFFSET
OUTER_APPLY
OUTPUT
OUTPUT_INSERTED
PAREN_CLOSE
PAREN_SPACE_OPEN
ROWS
ROWS_ONLY
SPACE
TOP
TOP_PAREN
UNICODE_STRING_START
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 572
def complex_expression_sql_append(sql, op, args)
  case op
  when :'||'
    super(sql, :+, args)
  when :LIKE, :"NOT LIKE"
    super(sql, op, args.map{|a| Sequel.lit(["(", " COLLATE #{CASE_SENSITIVE_COLLATION})"], a)})
  when :ILIKE, :"NOT ILIKE"
    super(sql, (op == :ILIKE ? :LIKE : :"NOT LIKE"), args.map{|a| Sequel.lit(["(", " COLLATE #{CASE_INSENSITIVE_COLLATION})"], a)})
  when :<<, :>>
    complex_expression_emulate_append(sql, op, args)
  when :extract
    part = args.at(0)
    raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part]
    if part == :second
      expr = args.at(1)
      sql << DATEPART_SECOND_OPEN << format.to_s << COMMA
      literal_append(sql, expr)
      sql << DATEPART_SECOND_MIDDLE
      literal_append(sql, expr)
      sql << 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 603
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 612
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 617
def disable_insert_output
  clone(:disable_insert_output=>true)
end
escape_like(string) click to toggle source

MSSQL treats [] as a metacharacter in LIKE expresions.

# File lib/sequel/adapters/shared/mssql.rb, line 622
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 633
def insert_select(*values)
  return unless supports_insert_select?
  with_sql_first(insert_select_sql(*values))
end
insert_select_sql(*values) click to toggle source

Add OUTPUT clause unless there is already an existing output clause, then return the SQL to insert.

# File lib/sequel/adapters/shared/mssql.rb, line 640
def insert_select_sql(*values)
  ds = (opts[:output] || opts[:returning]) ? self : output(nil, [SQL::ColumnAll.new(:inserted)])
  ds.insert_sql(*values)
end
into(table) click to toggle source

Specify a table for a SELECT … INTO query.

# File lib/sequel/adapters/shared/mssql.rb, line 646
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 567
def mssql_unicode_strings
  defined?(@mssql_unicode_strings) ? @mssql_unicode_strings : (@mssql_unicode_strings = db.mssql_unicode_strings)
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 651
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 656
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 672
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 686
def quoted_identifier_append(sql, name)
  sql << BRACKET_OPEN << name.to_s.gsub(/\]/, DOUBLE_BRACKET_CLOSE) << BRACKET_CLOSE
end
returning(*values) click to toggle source

Emulate RETURNING using the output clause. This only handles values that are simple column references.

# File lib/sequel/adapters/shared/mssql.rb, line 691
def returning(*values)
  values = values.map do |v|
    unless r = unqualified_column_for(v)
      raise(Error, "cannot emulate RETURNING via OUTPUT for value: #{v.inspect}")
    end
    r
  end
  clone(:returning=>values)
end
select_sql() click to toggle source

On MSSQL 2012+ add a default order to the current dataset if an offset is used. The default offset emulation using a subquery would be used in the unordered case by default, and that also adds a default order, so it's better to just avoid the subquery.

# File lib/sequel/adapters/shared/mssql.rb, line 705
def select_sql
  if @opts[:offset] && !@opts[:order] && is_2012_or_later?
    order(1).select_sql
  else
    super
  end
end
server_version() click to toggle source

The version of the database server.

# File lib/sequel/adapters/shared/mssql.rb, line 714
def server_version
  db.server_version(@opts[:server])
end
supports_cte?(type=:select) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 718
def supports_cte?(type=:select)
  is_2005_or_later?
end
supports_group_cube?() click to toggle source

MSSQL 2005+ supports GROUP BY CUBE.

# File lib/sequel/adapters/shared/mssql.rb, line 723
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 728
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 733
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 738
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 743
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 748
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 753
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 758
def supports_multiple_column_in?
  false
end
supports_offsets_in_correlated_subqueries?() click to toggle source

MSSQL 2012+ supports offsets in correlated subqueries.

# File lib/sequel/adapters/shared/mssql.rb, line 763
def supports_offsets_in_correlated_subqueries?
  is_2012_or_later?
end
supports_output_clause?() click to toggle source

MSSQL 2005+ supports the OUTPUT clause.

# File lib/sequel/adapters/shared/mssql.rb, line 768
def supports_output_clause?
  is_2005_or_later?
end
supports_returning?(type) click to toggle source

MSSQL 2005+ can emulate RETURNING via the OUTPUT clause.

# File lib/sequel/adapters/shared/mssql.rb, line 773
def supports_returning?(type)
  supports_insert_select?
end
supports_where_true?() click to toggle source

MSSQL cannot use WHERE 1.

# File lib/sequel/adapters/shared/mssql.rb, line 783
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 778
def supports_window_functions?
  true
end

Protected Instance Methods

_import(columns, values, opts=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 793
def _import(columns, values, opts=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 807
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 831
def default_timestamp_format
  DEFAULT_TIMESTAMP_FORMAT
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 842
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 836
def delete_from_sql(sql)
  sql << FROM
  source_list_append(sql, @opts[:from][0..0])
end
delete_output_sql(sql) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 850
def delete_output_sql(sql)
  output_sql(sql, :DELETED)
end
emulate_function?(name) 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 858
def emulate_function?(name)
  name == :char_length || name == :trim
end
emulate_function_sql_append(sql, f) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 862
def emulate_function_sql_append(sql, f)
  case f.name
  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)))
  end
end
emulate_offset_with_row_number?() click to toggle source

Microsoft SQL Server 2012 has native support for offsets, but only for ordered datasets.

# File lib/sequel/adapters/shared/mssql.rb, line 872
def emulate_offset_with_row_number?
  super && !(is_2012_or_later? && @opts[:order])
end
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 878
def first_primary_key
  @db.schema(self).map{|k, v| k if v[:primary_key] == true}.compact.first
end
insert_output_sql(sql) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 882
def insert_output_sql(sql)
  output_sql(sql, :INSERTED)
end
Also aliased as: update_output_sql
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 814
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 819
def is_2008_or_later?
  server_version >= 10000000
end
is_2012_or_later?() click to toggle source

Whether we are using SQL Server 2012 or later.

# File lib/sequel/adapters/shared/mssql.rb, line 824
def is_2012_or_later?
  server_version >= 11000000
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 888
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 900
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 906
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 911
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 917
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 923
def literal_true
  BOOL_TRUE
end
multi_insert_sql_strategy() click to toggle source

MSSQL 2008+ supports multiple rows in the VALUES clause, older versions can use UNION.

# File lib/sequel/adapters/shared/mssql.rb, line 929
def multi_insert_sql_strategy
  is_2008_or_later? ? :values : :union
end
output_list_sql(sql, output) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 999
def output_list_sql(sql, 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
output_returning_sql(sql, type, values) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 1013
def output_returning_sql(sql, type, values)
  sql << OUTPUT
  if values.empty?
    literal_append(sql, SQL::ColumnAll.new(type))
  else
    values = values.map do |v|
      case v
      when SQL::AliasedExpression
        Sequel.qualify(type, v.expression).as(v.alias)
      else
        Sequel.qualify(type, v)
      end
    end
    column_list_append(sql, values)
  end
end
output_sql(sql, type) click to toggle source

SQL fragment for MSSQL's OUTPUT clause.

# File lib/sequel/adapters/shared/mssql.rb, line 990
def output_sql(sql, type)
  return unless supports_output_clause?
  if output = @opts[:output]
    output_list_sql(sql, output)
  elsif values = @opts[:returning]
    output_returning_sql(sql, type, values)
  end
end
select_into_sql(sql) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 933
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 942
def select_limit_sql(sql)
  if l = @opts[:limit]
    return if is_2012_or_later? && @opts[:order] && @opts[:offset]

    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 959
def select_lock_sql(sql)
  case @opts[:lock]
  when :update
    sql << UPDLOCK
  when :dirty
    sql << NOLOCK
  else
    super
  end
end
select_order_sql(sql) click to toggle source

On 2012+ when there is an order with an offset, append the offset (and possible limit) at the end of the order clause.

Calls superclass method
# File lib/sequel/adapters/shared/mssql.rb, line 972
def select_order_sql(sql)
  super
  if is_2012_or_later? && @opts[:order]
    if o = @opts[:offset]
      sql << OFFSET
      literal_append(sql, o)
      sql << ROWS

      if l = @opts[:limit]
        sql << FETCH_NEXT
        literal_append(sql, l)
        sql << ROWS_ONLY
      end
    end
  end
end
timestamp_precision() click to toggle source

MSSQL supports millisecond timestamp precision.

# File lib/sequel/adapters/shared/mssql.rb, line 1031
def timestamp_precision
  3
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: insert_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 1036
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 1041
def uses_with_rollup?
  !is_2008_or_later?
end