Module | Sequel::Access |
In: |
lib/sequel/adapters/shared/access.rb
|
DATE_FORMAT | = | '#%Y-%m-%d#'.freeze |
TIMESTAMP_FORMAT | = | '#%Y-%m-%d %H:%M:%S#'.freeze |
TOP | = | " TOP ".freeze |
BRACKET_CLOSE | = | Dataset::BRACKET_CLOSE |
BRACKET_OPEN | = | Dataset::BRACKET_OPEN |
PAREN_CLOSE | = | Dataset::PAREN_CLOSE |
PAREN_OPEN | = | Dataset::PAREN_OPEN |
INTO | = | Dataset::INTO |
FROM | = | Dataset::FROM |
SPACE | = | Dataset::SPACE |
NOT_EQUAL | = | ' <> '.freeze |
OPS | = | {:'%'=>' Mod '.freeze, :'||'=>' & '.freeze} |
BOOL_FALSE | = | '0'.freeze |
BOOL_TRUE | = | '-1'.freeze |
DATE_FUNCTION | = | 'Date()'.freeze |
NOW_FUNCTION | = | 'Now()'.freeze |
TIME_FUNCTION | = | 'Time()'.freeze |
CAST_TYPES | = | {String=>:CStr, Integer=>:CLng, Date=>:CDate, Time=>:CDate, DateTime=>:CDate, Numeric=>:CDec, BigDecimal=>:CDec, File=>:CStr, Float=>:CDbl, TrueClass=>:CBool, FalseClass=>:CBool} |
EMULATED_FUNCTION_MAP | = | {:char_length=>:len} |
EXTRACT_MAP | = | {:year=>"'yyyy'", :month=>"'m'", :day=>"'d'", :hour=>"'h'", :minute=>"'n'", :second=>"'s'"} |
COMMA | = | Dataset::COMMA |
DATEPART_OPEN | = | "datepart(".freeze |
Access doesn‘t support CASE, but it can be emulated with nested IIF function calls.
# File lib/sequel/adapters/shared/access.rb, line 121 121: def case_expression_sql_append(sql, ce) 122: literal_append(sql, ce.with_merged_expression.conditions.reverse.inject(ce.default){|exp,(cond,val)| Sequel::SQL::Function.new(:IIF, cond, val, exp)}) 123: end
Access doesn‘t support CAST, it uses separate functions for type conversion
# File lib/sequel/adapters/shared/access.rb, line 127 127: def cast_sql_append(sql, expr, type) 128: sql << CAST_TYPES.fetch(type, type).to_s 129: sql << PAREN_OPEN 130: literal_append(sql, expr) 131: sql << PAREN_CLOSE 132: end
# File lib/sequel/adapters/shared/access.rb, line 134 134: def complex_expression_sql_append(sql, op, args) 135: case op 136: when :ILIKE 137: complex_expression_sql_append(sql, :LIKE, args) 138: when 'NOT ILIKE''NOT ILIKE' 139: complex_expression_sql_append(sql, 'NOT LIKE''NOT LIKE', args) 140: when :LIKE, 'NOT LIKE''NOT LIKE' 141: sql << PAREN_OPEN 142: literal_append(sql, args.at(0)) 143: sql << SPACE << op.to_s << SPACE 144: literal_append(sql, args.at(1)) 145: sql << PAREN_CLOSE 146: when '!=''!=' 147: sql << PAREN_OPEN 148: literal_append(sql, args.at(0)) 149: sql << NOT_EQUAL 150: literal_append(sql, args.at(1)) 151: sql << PAREN_CLOSE 152: when '%''%', '||''||' 153: sql << PAREN_OPEN 154: c = false 155: op_str = OPS[op] 156: args.each do |a| 157: sql << op_str if c 158: literal_append(sql, a) 159: c ||= true 160: end 161: sql << PAREN_CLOSE 162: when :** 163: sql << PAREN_OPEN 164: literal_append(sql, args[0]) 165: sql << ' ^ ' 166: literal_append(sql, args[1]) 167: sql << PAREN_CLOSE 168: when :extract 169: part = args.at(0) 170: raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part] 171: sql << DATEPART_OPEN << format.to_s << COMMA 172: literal_append(sql, args.at(1)) 173: sql << PAREN_CLOSE 174: else 175: super 176: end 177: end
Use Date() and Now() for CURRENT_DATE and CURRENT_TIMESTAMP
# File lib/sequel/adapters/shared/access.rb, line 180 180: def constant_sql_append(sql, constant) 181: case constant 182: when :CURRENT_DATE 183: sql << DATE_FUNCTION 184: when :CURRENT_TIMESTAMP 185: sql << NOW_FUNCTION 186: when :CURRENT_TIME 187: sql << TIME_FUNCTION 188: else 189: super 190: end 191: end
Emulate cross join by using multiple tables in the FROM clause.
# File lib/sequel/adapters/shared/access.rb, line 194 194: def cross_join(table) 195: clone(:from=>@opts[:from] + [table]) 196: end
Specify a table for a SELECT … INTO query.
# File lib/sequel/adapters/shared/access.rb, line 204 204: def into(table) 205: clone(:into => table) 206: end