module Sequel::MSSQL

Constants

CONSTANT_MAP
EXTRACT_MAP
LIMIT_ALL

Public Class Methods

mock_adapter_setup(db) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 10
def self.mock_adapter_setup(db)
  db.instance_exec do
    @server_version = 11000000
  end
end

Public Instance Methods

complex_expression_sql_append(sql, op, args) click to toggle source
Calls superclass method
# File lib/sequel/adapters/shared/mssql.rb, line 525
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 Latin1_General_CS_AS)"], a)})
  when :ILIKE, :"NOT ILIKE"
    super(sql, (op == :ILIKE ? :LIKE : :"NOT LIKE"), args.map{|a| Sequel.lit(["(", " COLLATE Latin1_General_CI_AS)"], a)})
  when :<<, :>>
    complex_expression_emulate_append(sql, op, args)
  when :extract
    part = args[0]
    raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part]
    if part == :second
      expr = args[1]
      sql << "CAST((datepart(" << format.to_s << ', '
      literal_append(sql, expr)
      sql << ') + datepart(ns, '
      literal_append(sql, expr)
      sql << ")/1000000000.0) AS double precision)"
    else
      sql << "datepart(" << format.to_s << ', '
      literal_append(sql, args[1])
      sql << ')'
    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 556
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 565
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 570
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 575
def escape_like(string)
  string.gsub(/[\\%_\[\]]/){|m| "\\#{m}"}
end
insert_select(*values) click to toggle source

Insert a record, returning the record inserted, using OUTPUT. Always returns nil without running an INSERT statement if #disable_insert_output is used. If the query runs but returns no values, returns false.

# File lib/sequel/adapters/shared/mssql.rb, line 588
def insert_select(*values)
  return unless supports_insert_select?
  with_sql_first(insert_select_sql(*values)) || false
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 595
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 601
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 516
def mssql_unicode_strings
  opts.has_key?(:mssql_unicode_strings) ? opts[: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 606
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 611
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, [Sequel[:deleted][:id], Sequel[:deleted][:name]])
dataset.output(:output_table, id: Sequel[:inserted][:id], name: Sequel[:inserted][:name])
# File lib/sequel/adapters/shared/mssql.rb, line 627
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 641
def quoted_identifier_append(sql, name)
  sql << '[' << name.to_s.gsub(/\]/, ']]') << ']'
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 646
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 660
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 669
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 673
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 678
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 683
def supports_group_rollup?
  is_2005_or_later?
end
supports_grouping_sets?() click to toggle source

MSSQL 2008+ supports GROUPING SETS

# File lib/sequel/adapters/shared/mssql.rb, line 688
def supports_grouping_sets?
  is_2008_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 693
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 698
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 703
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 708
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 713
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 718
def supports_multiple_column_in?
  false
end
supports_nowait?() click to toggle source

MSSQL supports NOWAIT.

# File lib/sequel/adapters/shared/mssql.rb, line 723
def supports_nowait?
  true
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 728
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 733
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 738
def supports_returning?(type)
  supports_insert_select?
end
supports_skip_locked?() click to toggle source

MSSQL uses READPAST to skip locked rows.

# File lib/sequel/adapters/shared/mssql.rb, line 743
def supports_skip_locked?
  true
end
supports_where_true?() click to toggle source

MSSQL cannot use WHERE 1.

# File lib/sequel/adapters/shared/mssql.rb, line 753
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 748
def supports_window_functions?
  true
end
with_mssql_unicode_strings(v) click to toggle source

Return a cloned dataset with the #mssql_unicode_strings option set.

# File lib/sequel/adapters/shared/mssql.rb, line 521
def with_mssql_unicode_strings(v)
  clone(:mssql_unicode_strings=>v)
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 763
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 777
def aggregate_dataset
  (options_overlap(Sequel::Dataset::COUNT_FROM_SELF_OPTS) && !options_overlap([:limit])) ? unordered.from_self : super
end
compound_from_self() click to toggle source

If the dataset using a order without a limit or offset or custom SQL, remove the order. Compounds on Microsoft SQL Server have undefined order unless the result is specifically ordered. Applying the current order before the compound doesn't work in all cases, such as when qualified identifiers are used. If you want to ensure a order for a compound dataset, apply the order after all compounds have been added.

Calls superclass method
# File lib/sequel/adapters/shared/mssql.rb, line 788
def compound_from_self
  if @opts[:offset] && !@opts[:limit] && !is_2012_or_later?
    clone(:limit=>LIMIT_ALL).from_self
  elsif @opts[:order]  && !(@opts[:sql] || @opts[:limit] || @opts[:offset])
    unordered
  else
    super
  end
end

Private Instance Methods

check_not_limited!(type) click to toggle source

Allow update and delete for unordered, limited datasets only.

Calls superclass method
# File lib/sequel/adapters/shared/mssql.rb, line 801
def check_not_limited!(type)
  return if @opts[:skip_limit_check] && type != :truncate
  raise Sequel::InvalidOperation, "Dataset##{type} not suppored on ordered, limited datasets" if opts[:order] && opts[:limit]
  super if type == :truncate || @opts[:offset]
end
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 825
def default_timestamp_format
  "'%Y-%m-%dT%H:%M:%S%N%z'"
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 836
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 830
def delete_from_sql(sql)
  sql << ' FROM '
  source_list_append(sql, @opts[:from][0..0])
end
delete_limit_sql(sql)
Alias for: update_limit_sql
delete_output_sql(sql) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 844
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 852
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 856
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 866
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 872
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 876
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 808
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 813
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 818
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 882
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 894
def literal_blob_append(sql, v)
  sql << '0x' << v.unpack("H*").first
end
literal_date(v) click to toggle source

Use YYYYmmdd format, since that's the only format that is multilanguage and not DATEFORMAT dependent.

# File lib/sequel/adapters/shared/mssql.rb, line 900
def literal_date(v)
  v.strftime("'%Y%m%d'")
end
literal_false() click to toggle source

Use 0 for false on MSSQL

# File lib/sequel/adapters/shared/mssql.rb, line 905
def literal_false
  '0'
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 911
def literal_string_append(sql, v)
  sql << (mssql_unicode_strings ? "N'" : "'")
  sql << v.gsub("'", "''").gsub(/\\((?:\r\n)|\n)/, '\\\\\\\\\\1\\1') << "'"
end
literal_true() click to toggle source

Use 1 for true on MSSQL

# File lib/sequel/adapters/shared/mssql.rb, line 917
def literal_true
  '1'
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 923
def multi_insert_sql_strategy
  is_2008_or_later? ? :values : :union
end
non_sql_option?(key) click to toggle source
Calls superclass method
# File lib/sequel/adapters/shared/mssql.rb, line 927
def non_sql_option?(key)
  super || key == :disable_insert_output || key == :mssql_unicode_strings
end
output_list_sql(sql, output) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 1024
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 << ' ('
      source_list_append(sql, column_list)
      sql << ')'
    end
  end
end
output_returning_sql(sql, type, values) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 1038
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
# File lib/sequel/adapters/shared/mssql.rb, line 1015
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
requires_emulating_nulls_first?() click to toggle source

MSSQL does not natively support NULLS FIRST/LAST.

# File lib/sequel/adapters/shared/mssql.rb, line 1056
def requires_emulating_nulls_first?
  true
end
select_into_sql(sql) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 931
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 2000 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 940
def select_limit_sql(sql)
  if l = @opts[:limit]
    return if is_2012_or_later? && @opts[:order] && @opts[:offset]
    shared_limit_sql(sql, l)
  end
end
select_lock_sql(sql) click to toggle source

Handle dirty, skip locked, and for update locking

Calls superclass method
# File lib/sequel/adapters/shared/mssql.rb, line 970
def select_lock_sql(sql)
  lock = @opts[:lock]
  skip_locked = @opts[:skip_locked]
  nowait = @opts[:nowait]
  for_update = lock == :update
  dirty = lock == :dirty
  lock_hint = for_update || dirty

  if lock_hint || skip_locked
    sql << " WITH ("

    if lock_hint
      sql << (for_update ? 'UPDLOCK' : 'NOLOCK')
    end

    if skip_locked || nowait
      sql << ', ' if lock_hint
      sql << (skip_locked ? "READPAST" : "NOWAIT")
    end

    sql << ')'
  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 998
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
shared_limit_sql(sql, l) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 947
def shared_limit_sql(sql, l)
  if is_2005_or_later?
    if l == LIMIT_ALL
      sql << " TOP (100) PERCENT"
    else
      sql << " TOP ("
      literal_append(sql, l)
      sql << ')'
    end
  else
    sql << " TOP "
    literal_append(sql, l)
  end
end
sqltime_precision() click to toggle source

MSSQL supports 100-nsec precision for time columns, but ruby by default only supports usec precision.

# File lib/sequel/adapters/shared/mssql.rb, line 1062
def sqltime_precision
  6
end
timestamp_precision() click to toggle source

MSSQL supports millisecond timestamp precision for datetime columns. 100-nsec precision is supported for datetime2 columns, but Sequel does not know what the column type is when formatting values.

# File lib/sequel/adapters/shared/mssql.rb, line 1069
def timestamp_precision
  3
end
update_from_sql(sql)
Alias for: delete_from2_sql
update_limit_sql(sql) click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 962
def update_limit_sql(sql)
  if l = @opts[:limit]
    shared_limit_sql(sql, l)
  end
end
Also aliased as: delete_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 1074
def update_table_sql(sql)
  sql << ' '
  source_list_append(sql, @opts[:from][0..0])
end
uses_with_rollup?() click to toggle source
# File lib/sequel/adapters/shared/mssql.rb, line 1079
def uses_with_rollup?
  !is_2008_or_later?
end