module Sequel::Access

Constants

BOOL_FALSE
BOOL_TRUE
BRACKET_CLOSE
BRACKET_OPEN
CAST_TYPES
COMMA
DATEPART_OPEN
DATE_FORMAT
DATE_FUNCTION
EMULATED_FUNCTION_MAP
EXTRACT_MAP
FROM
INTO
NOT_EQUAL
NOW_FUNCTION
OPS

EXTRACT_MAP.each_value(&:freeze) # SEQUEL5

PAREN_CLOSE
PAREN_OPEN
SPACE
TIMESTAMP_FORMAT
TIME_FUNCTION
TOP

Public Instance Methods

case_expression_sql_append(sql, ce) click to toggle source

Access doesn’t support CASE, but it can be emulated with nested IIF function calls.

# File lib/sequel/adapters/shared/access.rb, line 134
def case_expression_sql_append(sql, ce)
  literal_append(sql, ce.with_merged_expression.conditions.reverse.inject(ce.default){|exp,(cond,val)| Sequel::SQL::Function.new(:IIF, cond, val, exp)})
end
cast_sql_append(sql, expr, type) click to toggle source

Access doesn’t support CAST, it uses separate functions for type conversion

# File lib/sequel/adapters/shared/access.rb, line 140
def cast_sql_append(sql, expr, type)
  sql << CAST_TYPES.fetch(type, type).to_s
  sql << '('
  literal_append(sql, expr)
  sql << ')'
end
complex_expression_sql_append(sql, op, args) click to toggle source
# File lib/sequel/adapters/shared/access.rb, line 147
def complex_expression_sql_append(sql, op, args)
  case op
  when :ILIKE
    complex_expression_sql_append(sql, :LIKE, args)
  when :'NOT ILIKE'
    complex_expression_sql_append(sql, :'NOT LIKE', args)
  when :LIKE, :'NOT LIKE'
    sql << '('
    literal_append(sql, args[0])
    sql << ' ' << op.to_s << ' '
    literal_append(sql, args[1])
    sql << ')'
  when :'!='
    sql << '('
    literal_append(sql, args[0])
    sql << ' <> '
    literal_append(sql, args[1])
    sql << ')'
  when :'%', :'||'
    sql << '('
    c = false
    op_str = OPS[op]
    args.each do |a|
      sql << op_str if c
      literal_append(sql, a)
      c ||= true
    end
    sql << ')'
  when :**
    sql << '('
    literal_append(sql, args[0])
    sql << ' ^ '
    literal_append(sql, args[1])
    sql << ')'
  when :extract
    part = args[0]
    raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part]
    sql << "datepart(" << format.to_s << ', '
    literal_append(sql, args[1])
    sql << ')'
  else
    super
  end
end
constant_sql_append(sql, constant) click to toggle source

Use Date() and Now() for CURRENT_DATE and CURRENT_TIMESTAMP

# File lib/sequel/adapters/shared/access.rb, line 193
def constant_sql_append(sql, constant)
  case constant
  when :CURRENT_DATE
    sql << 'Date()'
  when :CURRENT_TIMESTAMP
    sql << 'Now()'
  when :CURRENT_TIME
    sql << 'Time()'
  else
    super
  end
end
cross_join(table) click to toggle source

Emulate cross join by using multiple tables in the FROM clause.

# File lib/sequel/adapters/shared/access.rb, line 207
def cross_join(table)
  clone(:from=>@opts[:from] + [table])
end
escape_like(string) click to toggle source

Access uses [] to escape metacharacters, instead of backslashes.

# File lib/sequel/adapters/shared/access.rb, line 212
def escape_like(string)
  string.gsub(/[\*#?\[]/){|m| "[#{m}]"}
end
into(table) click to toggle source

Specify a table for a SELECT … INTO query.

# File lib/sequel/adapters/shared/access.rb, line 217
def into(table)
  clone(:into => table)
end
supports_derived_column_lists?() click to toggle source

Access does not support derived column lists.

# File lib/sequel/adapters/shared/access.rb, line 222
def supports_derived_column_lists?
  false
end
supports_intersect_except?() click to toggle source

Access doesn’t support INTERSECT or EXCEPT

# File lib/sequel/adapters/shared/access.rb, line 227
def supports_intersect_except?
  false
end
supports_is_true?() click to toggle source

Access does not support IS TRUE

# File lib/sequel/adapters/shared/access.rb, line 232
def supports_is_true?
  false
end
supports_join_using?() click to toggle source

Access doesn’t support JOIN USING

# File lib/sequel/adapters/shared/access.rb, line 237
def supports_join_using?
  false
end
supports_multiple_column_in?() click to toggle source

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

# File lib/sequel/adapters/shared/access.rb, line 242
def supports_multiple_column_in?
  false
end
truncate() click to toggle source

Access doesn’t support truncate, so do a delete instead.

# File lib/sequel/adapters/shared/access.rb, line 247
def truncate
  delete
  nil
end