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 122 122: def case_expression_sql_append(sql, ce) 123: literal_append(sql, ce.with_merged_expression.conditions.reverse.inject(ce.default){|exp,(cond,val)| Sequel::SQL::Function.new(:IIF, cond, val, exp)}) 124: end
Access doesn‘t support CAST, it uses separate functions for type conversion
# File lib/sequel/adapters/shared/access.rb, line 128 128: def cast_sql_append(sql, expr, type) 129: sql << CAST_TYPES.fetch(type, type).to_s 130: sql << PAREN_OPEN 131: literal_append(sql, expr) 132: sql << PAREN_CLOSE 133: end
# File lib/sequel/adapters/shared/access.rb, line 135 135: def complex_expression_sql_append(sql, op, args) 136: case op 137: when :ILIKE 138: complex_expression_sql_append(sql, :LIKE, args) 139: when 'NOT ILIKE''NOT ILIKE' 140: complex_expression_sql_append(sql, 'NOT LIKE''NOT LIKE', args) 141: when :LIKE, 'NOT LIKE''NOT LIKE' 142: sql << PAREN_OPEN 143: literal_append(sql, args.at(0)) 144: sql << SPACE << op.to_s << SPACE 145: literal_append(sql, args.at(1)) 146: sql << PAREN_CLOSE 147: when '!=''!=' 148: sql << PAREN_OPEN 149: literal_append(sql, args.at(0)) 150: sql << NOT_EQUAL 151: literal_append(sql, args.at(1)) 152: sql << PAREN_CLOSE 153: when '%''%', '||''||' 154: sql << PAREN_OPEN 155: c = false 156: op_str = OPS[op] 157: args.each do |a| 158: sql << op_str if c 159: literal_append(sql, a) 160: c ||= true 161: end 162: sql << PAREN_CLOSE 163: when :extract 164: part = args.at(0) 165: raise(Sequel::Error, "unsupported extract argument: #{part.inspect}") unless format = EXTRACT_MAP[part] 166: sql << DATEPART_OPEN << format.to_s << COMMA 167: literal_append(sql, args.at(1)) 168: sql << PAREN_CLOSE 169: else 170: super 171: end 172: end
Use Date() and Now() for CURRENT_DATE and CURRENT_TIMESTAMP
# File lib/sequel/adapters/shared/access.rb, line 175 175: def constant_sql_append(sql, constant) 176: case constant 177: when :CURRENT_DATE 178: sql << DATE_FUNCTION 179: when :CURRENT_TIMESTAMP 180: sql << NOW_FUNCTION 181: when :CURRENT_TIME 182: sql << TIME_FUNCTION 183: else 184: super 185: end 186: end
Emulate cross join by using multiple tables in the FROM clause.
# File lib/sequel/adapters/shared/access.rb, line 189 189: def cross_join(table) 190: clone(:from=>@opts[:from] + [table]) 191: end
Specify a table for a SELECT … INTO query.
# File lib/sequel/adapters/shared/access.rb, line 199 199: def into(table) 200: clone(:into => table) 201: end