[sequel] sequel里面的小动作
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花花公子
2009-04-15
from lib/sequel/core_sql.rb
# If no argument is given, returns a Sequel::SQL::ColumnAll object specifying all
# columns for this table.
# If an argument is given, returns a Sequel::SQL::NumericExpression using the *
# (multiplication) operator with this and the given argument.
#
# :table.* # SQL: table.*
# :column * 2 # SQL: column * 2
class Symbol
def *(ce=(arg=false;nil))
return super(ce) unless arg == false
Sequel::SQL::ColumnAll.new(self);
end
end
巧妙利用默认值的特性，保证没有参数传入和传入一个参数执行不同的动作。 |
