Module: Sequel::MSSQL::DatasetMethods

Includes:
EmulateOffsetWithRowNumber
Included in:
ADO::MSSQL::Dataset, JDBC::JTDS::Dataset, ODBC::MSSQL::Dataset, TinyTDS::Dataset
Defined in:
lib/sequel/adapters/shared/mssql.rb

Constant Summary collapse

BOOL_TRUE = 
'1'.freeze
BOOL_FALSE = 
'0'.freeze
COMMA_SEPARATOR = 
', '.freeze
NOLOCK = 
' WITH (NOLOCK)'.freeze
UPDLOCK = 
' WITH (UPDLOCK)'.freeze
WILDCARD = 
LiteralString.new('*').freeze
CONSTANT_MAP = 
{:CURRENT_DATE=>'CAST(CURRENT_TIMESTAMP AS DATE)'.freeze, :CURRENT_TIME=>'CAST(CURRENT_TIMESTAMP AS TIME)'.freeze}
EXTRACT_MAP = 
{:year=>"yy", :month=>"m", :day=>"d", :hour=>"hh", :minute=>"n", :second=>"s"}
BRACKET_CLOSE = 
Dataset::BRACKET_CLOSE
BRACKET_OPEN = 
Dataset::BRACKET_OPEN
COMMA = 
Dataset::COMMA
PAREN_CLOSE = 
Dataset::PAREN_CLOSE
PAREN_SPACE_OPEN = 
Dataset::PAREN_SPACE_OPEN
SPACE = 
Dataset::SPACE
FROM = 
Dataset::FROM
APOS = 
Dataset::APOS
APOS_RE = 
Dataset::APOS_RE
DOUBLE_APOS = 
Dataset::DOUBLE_APOS
INTO = 
Dataset::INTO
DOUBLE_BRACKET_CLOSE = 
']]'.freeze
DATEPART_SECOND_OPEN = 
"CAST((datepart(".freeze
DATEPART_SECOND_MIDDLE = 
') + datepart(ns, '.freeze
DATEPART_SECOND_CLOSE = 
")/1000000000.0) AS double precision)".freeze
DATEPART_OPEN = 
"datepart(".freeze
OUTPUT_INSERTED = 
" OUTPUT INSERTED.*".freeze
HEX_START = 
'0x'.freeze
UNICODE_STRING_START = 
"N'".freeze
BACKSLASH_CRLF_RE = 
/\\((?:\r\n)|\n)/.freeze
BACKSLASH_CRLF_REPLACE = 
'\\\\\\\\\\1\\1'.freeze
TOP_PAREN = 
" TOP (".freeze
TOP = 
" TOP ".freeze
OUTPUT = 
" OUTPUT ".freeze
HSTAR = 
"H*".freeze
CASE_SENSITIVE_COLLATION = 
'Latin1_General_CS_AS'.freeze
CASE_INSENSITIVE_COLLATION = 
'Latin1_General_CI_AS'.freeze
DEFAULT_TIMESTAMP_FORMAT = 
"'%Y-%m-%dT%H:%M:%S%N%z'".freeze
FORMAT_DATE = 
"'%Y%m%d'".freeze
CROSS_APPLY = 
'CROSS APPLY'.freeze
OUTER_APPLY = 
'OUTER APPLY'.freeze
OFFSET = 
" OFFSET ".freeze
ROWS = 
" ROWS".freeze
ROWS_ONLY = 
" ROWS ONLY".freeze
FETCH_NEXT = 
" FETCH NEXT ".freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from EmulateOffsetWithRowNumber

#empty?

Instance Attribute Details

#mssql_unicode_strings ⇒ Object

Use the database’s mssql_unicode_strings setting if the dataset hasn’t overridden it.



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# 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

Instance Method Details

#complex_expression_sql_append(sql, op, args) ⇒ Object

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



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# 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) ⇒ Object

MSSQL doesn’t support the SQL standard CURRENT_DATE or CURRENT_TIME



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# 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) ⇒ Object

Uses CROSS APPLY to join the given table into the current dataset.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 612

def cross_apply(table)
  join_table(:cross_apply, table)
end

#disable_insert_output ⇒ Object

Disable the use of INSERT OUTPUT



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# File 'lib/sequel/adapters/shared/mssql.rb', line 617

def disable_insert_output
  clone(:disable_insert_output=>true)
end

#escape_like(string) ⇒ Object

MSSQL treats [] as a metacharacter in LIKE expresions.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 622

def escape_like(string)
  string.gsub(/[\\%_\[\]]/){|m| "\\#{m}"}
end

#full_text_search(cols, terms, opts = OPTS) ⇒ Object

MSSQL uses the CONTAINS keyword for full text search



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# File 'lib/sequel/adapters/shared/mssql.rb', line 627

def full_text_search(cols, terms, opts = OPTS)
  terms = "\"#{terms.join('" OR "')}\"" if terms.is_a?(Array)
  filter("CONTAINS (?, ?)", cols, terms)
end

#insert_select(*values) ⇒ Object

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



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# 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) ⇒ Object

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



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# 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) ⇒ Object

Specify a table for a SELECT … INTO query.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 646

def into(table)
  clone(:into => table)
end

#nolock ⇒ Object

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



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# File 'lib/sequel/adapters/shared/mssql.rb', line 651

def nolock
  lock_style(:dirty)
end

#outer_apply(table) ⇒ Object

Uses OUTER APPLY to join the given table into the current dataset.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 656

def outer_apply(table)
  join_table(:outer_apply, table)
end

#output(into, values) ⇒ Object

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)

Raises:



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# 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) ⇒ Object

MSSQL uses [] to quote identifiers.



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# 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) ⇒ Object

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



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# 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 ⇒ Object

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.



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# 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 ⇒ Object

The version of the database server.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 714

def server_version
  db.server_version(@opts[:server])
end

#supports_cte?(type = :select) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 718

def supports_cte?(type=:select)
  is_2005_or_later?
end

#supports_group_cube? ⇒ Boolean

MSSQL 2005+ supports GROUP BY CUBE.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 723

def supports_group_cube?
  is_2005_or_later?
end

#supports_group_rollup? ⇒ Boolean

MSSQL 2005+ supports GROUP BY ROLLUP

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 728

def supports_group_rollup?
  is_2005_or_later?
end

#supports_insert_select? ⇒ Boolean

MSSQL supports insert_select via the OUTPUT clause.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 733

def supports_insert_select?
  supports_output_clause? && !opts[:disable_insert_output]
end

#supports_intersect_except? ⇒ Boolean

MSSQL 2005+ supports INTERSECT and EXCEPT

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 738

def supports_intersect_except?
  is_2005_or_later?
end

#supports_is_true? ⇒ Boolean

MSSQL does not support IS TRUE

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 743

def supports_is_true?
  false
end

#supports_join_using? ⇒ Boolean

MSSQL doesn’t support JOIN USING

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 748

def supports_join_using?
  false
end

#supports_modifying_joins? ⇒ Boolean

MSSQL 2005+ supports modifying joined datasets

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 753

def supports_modifying_joins?
  is_2005_or_later?
end

#supports_multiple_column_in? ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 758

def supports_multiple_column_in?
  false
end

#supports_offsets_in_correlated_subqueries? ⇒ Boolean

MSSQL 2012+ supports offsets in correlated subqueries.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 763

def supports_offsets_in_correlated_subqueries?
  is_2012_or_later?
end

#supports_output_clause? ⇒ Boolean

MSSQL 2005+ supports the OUTPUT clause.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 768

def supports_output_clause?
  is_2005_or_later?
end

#supports_returning?(type) ⇒ Boolean

MSSQL 2005+ can emulate RETURNING via the OUTPUT clause.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 773

def supports_returning?(type)
  supports_insert_select?
end

#supports_where_true? ⇒ Boolean

MSSQL cannot use WHERE 1.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 783

def supports_where_true?
  false
end

#supports_window_functions? ⇒ Boolean

MSSQL 2005+ supports window functions

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 778

def supports_window_functions?
  true
end