module Sequel::Access::DatasetMethods

Constants

CAST_TYPES
EXTRACT_MAP
OPS

Public Instance Methods

case_expression_sql_append(sql, ce) click to toggle source

Access doesn’t support CASE, so emulate it with nested IIF function calls.

   # File lib/sequel/adapters/shared/access.rb
95 def case_expression_sql_append(sql, ce)
96   literal_append(sql, ce.with_merged_expression.conditions.reverse.inject(ce.default){|exp,(cond,val)| Sequel::SQL::Function.new(:IIF, cond, val, exp)})
97 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
101 def cast_sql_append(sql, expr, type)
102   sql << CAST_TYPES.fetch(type, type).to_s
103   sql << '('
104   literal_append(sql, expr)
105   sql << ')'
106 end
complex_expression_sql_append(sql, op, args) click to toggle source
Calls superclass method
    # File lib/sequel/adapters/shared/access.rb
108 def complex_expression_sql_append(sql, op, args)
109   case op
110   when :ILIKE
111     complex_expression_sql_append(sql, :LIKE, args)
112   when :'NOT ILIKE'
113     complex_expression_sql_append(sql, :'NOT LIKE', args)
114   when :'!='
115     sql << '('
116     literal_append(sql, args[0])
117     sql << ' <> '
118     literal_append(sql, args[1])
119     sql << ')'
120   when :'%', :'||'
121     sql << '('
122     c = false
123     op_str = OPS[op]
124     args.each do |a|
125       sql << op_str if c
126       literal_append(sql, a)
127       c ||= true
128     end
129     sql << ')'
130   when :**
131     sql << '('
132     literal_append(sql, args[0])
133     sql << ' ^ '
134     literal_append(sql, args[1])
135     sql << ')'
136   when :extract
137     part = args[0]
138     raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part]
139     sql << "datepart(" << format.to_s << ', '
140     literal_append(sql, args[1])
141     sql << ')'
142   else
143     super
144   end
145 end
constant_sql_append(sql, constant) click to toggle source

Use Date(), Now(), and Time() for CURRENT_DATE, CURRENT_TIMESTAMP, and CURRENT_TIME

Calls superclass method
    # File lib/sequel/adapters/shared/access.rb
148 def constant_sql_append(sql, constant)
149   case constant
150   when :CURRENT_DATE
151     sql << 'Date()'
152   when :CURRENT_TIMESTAMP
153     sql << 'Now()'
154   when :CURRENT_TIME
155     sql << 'Time()'
156   else
157     super
158   end
159 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
162 def cross_join(table)
163   clone(:from=>@opts[:from] + [table])
164 end
escape_like(string) click to toggle source

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

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

Specify a table for a SELECT … INTO query.

    # File lib/sequel/adapters/shared/access.rb
172 def into(table)
173   clone(:into => table)
174 end
quoted_identifier_append(sql, v) click to toggle source

Access uses [] for quoting identifiers, and can’t handle ] inside identifiers.

    # File lib/sequel/adapters/shared/access.rb
178 def quoted_identifier_append(sql, v)
179   sql << '[' << v.to_s << ']'
180 end
supports_derived_column_lists?() click to toggle source

Access does not support derived column lists.

    # File lib/sequel/adapters/shared/access.rb
183 def supports_derived_column_lists?
184   false
185 end
supports_intersect_except?() click to toggle source

Access doesn’t support INTERSECT or EXCEPT

    # File lib/sequel/adapters/shared/access.rb
188 def supports_intersect_except?
189   false
190 end
supports_is_true?() click to toggle source

Access does not support IS TRUE

    # File lib/sequel/adapters/shared/access.rb
193 def supports_is_true?
194   false
195 end
supports_join_using?() click to toggle source

Access doesn’t support JOIN USING

    # File lib/sequel/adapters/shared/access.rb
198 def supports_join_using?
199   false
200 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
203 def supports_multiple_column_in?
204   false
205 end
truncate() click to toggle source

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

    # File lib/sequel/adapters/shared/access.rb
208 def truncate
209   delete
210   nil
211 end

Private Instance Methods

literal_date(d) click to toggle source

Access uses # to quote dates

    # File lib/sequel/adapters/shared/access.rb
216 def literal_date(d)
217   d.strftime('#%Y-%m-%d#')
218 end
literal_datetime(t) click to toggle source

Access uses # to quote datetimes

    # File lib/sequel/adapters/shared/access.rb
221 def literal_datetime(t)
222   t.strftime('#%Y-%m-%d %H:%M:%S#')
223 end
Also aliased as: literal_time
literal_false() click to toggle source

Use 0 for false on MSSQL

    # File lib/sequel/adapters/shared/access.rb
227 def literal_false
228   '0'
229 end
literal_time(t)
Alias for: literal_datetime
literal_true() click to toggle source

Use -1 for true on MSSQL

    # File lib/sequel/adapters/shared/access.rb
232 def literal_true
233   '-1'
234 end
native_function_name(emulated_function) click to toggle source

Emulate the char_length function with len

Calls superclass method
    # File lib/sequel/adapters/shared/access.rb
237 def native_function_name(emulated_function)
238   if emulated_function == :char_length
239     'len'
240   else
241     super
242   end
243 end
requires_emulating_nulls_first?() click to toggle source

Access does not natively support NULLS FIRST/LAST.

    # File lib/sequel/adapters/shared/access.rb
246 def requires_emulating_nulls_first?
247   true
248 end
requires_like_escape?() click to toggle source

Access doesn’t support ESCAPE for LIKE.

    # File lib/sequel/adapters/shared/access.rb
251 def requires_like_escape?
252   false
253 end
select_from_sql(sql) click to toggle source

Access requires parentheses when joining more than one table

    # File lib/sequel/adapters/shared/access.rb
256 def select_from_sql(sql)
257   if f = @opts[:from]
258     sql << ' FROM '
259     if (j = @opts[:join]) && !j.empty?
260       sql << ('(' * j.length)
261     end
262     source_list_append(sql, f)
263   end
264 end
select_into_sql(sql) click to toggle source
    # File lib/sequel/adapters/shared/access.rb
266 def select_into_sql(sql)
267   if i = @opts[:into]
268     sql << " INTO "
269     identifier_append(sql, i)
270   end
271 end
select_join_sql(sql) click to toggle source

Access requires parentheses when joining more than one table

    # File lib/sequel/adapters/shared/access.rb
274 def select_join_sql(sql)
275   if js = @opts[:join]
276     js.each do |j|
277       literal_append(sql, j)
278       sql << ')'
279     end
280   end
281 end
select_limit_sql(sql) click to toggle source

Access uses TOP for limits

    # File lib/sequel/adapters/shared/access.rb
284 def select_limit_sql(sql)
285   if l = @opts[:limit]
286     sql << " TOP "
287     literal_append(sql, l)
288   end
289 end