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
DELETE_CLAUSE_METHODS = 
Dataset.clause_methods(:delete, %w'with delete from output from2 where')
INSERT_CLAUSE_METHODS = 
Dataset.clause_methods(:insert, %w'with insert into columns output values')
SELECT_CLAUSE_METHODS = 
Dataset.clause_methods(:select, %w'with select distinct limit columns into from lock join where group having order compounds')
UPDATE_CLAUSE_METHODS = 
Dataset.clause_methods(:update, %w'with update limit table set output from where')
UPDATE_CLAUSE_METHODS_2000 = 
Dataset.clause_methods(:update, %w'update table set output from where')
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
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
UNION_ALL = 
' UNION ALL '.freeze
SELECT_SPACE = 
'SELECT '.freeze
TIMESTAMP_USEC_FORMAT = 
".%03d".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

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from EmulateOffsetWithRowNumber

#select_sql

Instance Attribute Details

#mssql_unicode_strings ⇒ Object

Allow overriding of the mssql_unicode_strings option at the dataset level.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 426

def mssql_unicode_strings
  @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 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) ⇒ 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 464

def constant_sql_append(sql, constant)
  if c = CONSTANT_MAP[constant]
    sql << c
  else
    super
  end
end

#disable_insert_output ⇒ Object

Disable the use of INSERT OUTPUT



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# File 'lib/sequel/adapters/shared/mssql.rb', line 473

def disable_insert_output
  clone(:disable_insert_output=>true)
end

#disable_insert_output! ⇒ Object

Disable the use of INSERT OUTPUT, modifying the receiver



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# 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) ⇒ Object

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.



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# 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

#full_text_search(cols, terms, opts = {}) ⇒ Object

MSSQL uses the CONTAINS keyword for full text search



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# File 'lib/sequel/adapters/shared/mssql.rb', line 498

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

#initialize(db, opts = {}) ⇒ Object

Copy the mssql_unicode_strings option from the db object.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 429

def initialize(db, opts={})
  super
  @mssql_unicode_strings = db.mssql_unicode_strings
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 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) ⇒ Object

Specify a table for a SELECT … INTO query.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 510

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

#multi_insert_sql(columns, values) ⇒ Object

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



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# 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 ⇒ 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 529

def nolock
  lock_style(:dirty)
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 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) ⇒ Object

An output method that modifies the receiver.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 559

def output!(into, values)
  mutation_method(:output, into, values)
end

#quoted_identifier_append(sql, name) ⇒ Object

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



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# 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 ⇒ Object

The version of the database server.



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# File 'lib/sequel/adapters/shared/mssql.rb', line 570

def server_version
  db.server_version(@opts[:server])
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 575

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 580

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 585

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 590

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 595

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 600

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 605

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 610

def supports_multiple_column_in?
  false
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 615

def supports_output_clause?
  is_2005_or_later?
end

#supports_where_true? ⇒ Boolean

MSSQL cannot use WHERE 1.

Returns:

  • (Boolean) 


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# File 'lib/sequel/adapters/shared/mssql.rb', line 625

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 620

def supports_window_functions?
  true
end