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
93 def case_expression_sql_append(sql, ce)
94   literal_append(sql, ce.with_merged_expression.conditions.reverse.inject(ce.default){|exp,(cond,val)| Sequel::SQL::Function.new(:IIF, cond, val, exp)})
95 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
 99 def cast_sql_append(sql, expr, type)
100   sql << CAST_TYPES.fetch(type, type).to_s
101   sql << '('
102   literal_append(sql, expr)
103   sql << ')'
104 end
complex_expression_sql_append(sql, op, args) click to toggle source
Calls superclass method
    # File lib/sequel/adapters/shared/access.rb
106 def complex_expression_sql_append(sql, op, args)
107   case op
108   when :ILIKE
109     complex_expression_sql_append(sql, :LIKE, args)
110   when :'NOT ILIKE'
111     complex_expression_sql_append(sql, :'NOT LIKE', args)
112   when :'!='
113     sql << '('
114     literal_append(sql, args[0])
115     sql << ' <> '
116     literal_append(sql, args[1])
117     sql << ')'
118   when :'%', :'||'
119     sql << '('
120     c = false
121     op_str = OPS[op]
122     args.each do |a|
123       sql << op_str if c
124       literal_append(sql, a)
125       c ||= true
126     end
127     sql << ')'
128   when :**
129     sql << '('
130     literal_append(sql, args[0])
131     sql << ' ^ '
132     literal_append(sql, args[1])
133     sql << ')'
134   when :extract
135     part = args[0]
136     raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part]
137     sql << "datepart(" << format.to_s << ', '
138     literal_append(sql, args[1])
139     sql << ')'
140   else
141     super
142   end
143 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
146 def constant_sql_append(sql, constant)
147   case constant
148   when :CURRENT_DATE
149     sql << 'Date()'
150   when :CURRENT_TIMESTAMP
151     sql << 'Now()'
152   when :CURRENT_TIME
153     sql << 'Time()'
154   else
155     super
156   end
157 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
160 def cross_join(table)
161   clone(:from=>@opts[:from] + [table])
162 end
escape_like(string) click to toggle source

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

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

Specify a table for a SELECT … INTO query.

    # File lib/sequel/adapters/shared/access.rb
170 def into(table)
171   clone(:into => table)
172 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
176 def quoted_identifier_append(sql, v)
177   sql << '[' << v.to_s << ']'
178 end
supports_derived_column_lists?() click to toggle source

Access does not support derived column lists.

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

Access doesn't support INTERSECT or EXCEPT

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

Access does not support IS TRUE

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

Access doesn't support JOIN USING

    # File lib/sequel/adapters/shared/access.rb
196 def supports_join_using?
197   false
198 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
201 def supports_multiple_column_in?
202   false
203 end
truncate() click to toggle source

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

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

Private Instance Methods

literal_date(d) click to toggle source

Access uses # to quote dates

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

Access uses # to quote datetimes

    # File lib/sequel/adapters/shared/access.rb
219 def literal_datetime(t)
220   t.strftime('#%Y-%m-%d %H:%M:%S#')
221 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
225 def literal_false
226   '0'
227 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
230 def literal_true
231   '-1'
232 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
235 def native_function_name(emulated_function)
236   if emulated_function == :char_length
237     'len'
238   else
239     super
240   end
241 end
requires_emulating_nulls_first?() click to toggle source

Access does not natively support NULLS FIRST/LAST.

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

Access doesn't support ESCAPE for LIKE.

    # File lib/sequel/adapters/shared/access.rb
249 def requires_like_escape?
250   false
251 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
254 def select_from_sql(sql)
255   if f = @opts[:from]
256     sql << ' FROM '
257     if (j = @opts[:join]) && !j.empty?
258       sql << ('(' * j.length)
259     end
260     source_list_append(sql, f)
261   end
262 end
select_into_sql(sql) click to toggle source
    # File lib/sequel/adapters/shared/access.rb
264 def select_into_sql(sql)
265   if i = @opts[:into]
266     sql << " INTO "
267     identifier_append(sql, i)
268   end
269 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
272 def select_join_sql(sql)
273   if js = @opts[:join]
274     js.each do |j|
275       literal_append(sql, j)
276       sql << ')'
277     end
278   end
279 end
select_limit_sql(sql) click to toggle source

Access uses TOP for limits

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