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
- PAREN_CLOSE
- PAREN_OPEN
- SPACE
- TIMESTAMP_FORMAT
- TIME_FUNCTION
- TOP
Public Instance Methods
Access doesn't support CASE, but it can be emulated with nested IIF function calls.
# File lib/sequel/adapters/shared/access.rb, line 114 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 120 def cast_sql_append(sql, expr, type) sql << CAST_TYPES.fetch(type, type).to_s sql << PAREN_OPEN literal_append(sql, expr) sql << PAREN_CLOSE end
# File lib/sequel/adapters/shared/access.rb, line 127 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 << PAREN_OPEN literal_append(sql, args.at(0)) sql << SPACE << op.to_s << SPACE literal_append(sql, args.at(1)) sql << PAREN_CLOSE when :'!=' sql << PAREN_OPEN literal_append(sql, args.at(0)) sql << NOT_EQUAL literal_append(sql, args.at(1)) sql << PAREN_CLOSE when :'%', :'||' sql << PAREN_OPEN c = false op_str = OPS[op] args.each do |a| sql << op_str if c literal_append(sql, a) c ||= true end sql << PAREN_CLOSE when :** sql << PAREN_OPEN literal_append(sql, args[0]) sql << ' ^ ' literal_append(sql, args[1]) sql << PAREN_CLOSE when :extract part = args.at(0) raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part] sql << DATEPART_OPEN << format.to_s << COMMA literal_append(sql, args.at(1)) sql << PAREN_CLOSE else super end end
Use Date() and Now() for CURRENT_DATE and CURRENT_TIMESTAMP
# File lib/sequel/adapters/shared/access.rb, line 173 def constant_sql_append(sql, constant) case constant when :CURRENT_DATE sql << DATE_FUNCTION when :CURRENT_TIMESTAMP sql << NOW_FUNCTION when :CURRENT_TIME sql << TIME_FUNCTION else super end end
Emulate cross join by using multiple tables in the FROM clause.
# File lib/sequel/adapters/shared/access.rb, line 187 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 192 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 197 def into(table) clone(:into => table) end
Access does not support derived column lists.
# File lib/sequel/adapters/shared/access.rb, line 202 def supports_derived_column_lists? false end
Access doesn't support INTERSECT or EXCEPT
# File lib/sequel/adapters/shared/access.rb, line 207 def supports_intersect_except? false end
Access does not support IS TRUE
# File lib/sequel/adapters/shared/access.rb, line 212 def supports_is_true? false end
Access doesn't support JOIN USING
# File lib/sequel/adapters/shared/access.rb, line 217 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 222 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 227 def truncate delete nil end
Private Instance Methods
Access uses # to quote dates
# File lib/sequel/adapters/shared/access.rb, line 235 def literal_date(d) d.strftime(DATE_FORMAT) end
Access uses # to quote datetimes
# File lib/sequel/adapters/shared/access.rb, line 240 def literal_datetime(t) t.strftime(TIMESTAMP_FORMAT) end
Use 0 for false on MSSQL
# File lib/sequel/adapters/shared/access.rb, line 246 def literal_false BOOL_FALSE end
Use 0 for false on MSSQL
# File lib/sequel/adapters/shared/access.rb, line 251 def literal_true BOOL_TRUE end
Access uses [] for quoting identifiers
# File lib/sequel/adapters/shared/access.rb, line 292 def quoted_identifier_append(sql, v) sql << BRACKET_OPEN << v.to_s << BRACKET_CLOSE end
Access requires parentheses when joining more than one table
# File lib/sequel/adapters/shared/access.rb, line 256 def select_from_sql(sql) if f = @opts[:from] sql << FROM if (j = @opts[:join]) && !j.empty? sql << (PAREN_OPEN * j.length) end source_list_append(sql, f) end end
# File lib/sequel/adapters/shared/access.rb, line 266 def select_into_sql(sql) if i = @opts[:into] sql << INTO identifier_append(sql, i) end end
Access requires parentheses when joining more than one table
# File lib/sequel/adapters/shared/access.rb, line 274 def select_join_sql(sql) if js = @opts[:join] js.each do |j| literal_append(sql, j) sql << PAREN_CLOSE end end end