EXTRACT_MAP.each_value(&:freeze) # SEQUEL5
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
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
# 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
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
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
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
Specify a table for a SELECT … INTO query.
# File lib/sequel/adapters/shared/access.rb, line 217 def into(table) clone(:into => table) end
Access does not support derived column lists.
# File lib/sequel/adapters/shared/access.rb, line 222 def supports_derived_column_lists? false end
Access doesn’t support INTERSECT or EXCEPT
# File lib/sequel/adapters/shared/access.rb, line 227 def supports_intersect_except? false end
Access does not support IS TRUE
# File lib/sequel/adapters/shared/access.rb, line 232 def supports_is_true? false end
Access doesn’t support JOIN USING
# File lib/sequel/adapters/shared/access.rb, line 237 def supports_join_using? false end
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
Access doesn’t support truncate, so do a delete instead.
# File lib/sequel/adapters/shared/access.rb, line 247 def truncate delete nil end