翻译rails查询sqlite

Question

我如何翻译这些mysql查询以使用sqlite3？：

self.find(:first, :conditions => ['concat(first_name, \' \', middle_names, \' \', last_name) = ?', name])

self.find(:all, :conditions => ['(concat(first_name, \' \', last_name) LIKE ?) OR (concat(first_name, \' \', middle_names, \' \', last_name) LIKE ?)', "%#{name}%", "%#{name}%"])

Answer 1

||是SQLite连接运算符。所以这可能会奏效：

self.find(:first, :conditions => ['first_name || \' \' || middle_names || \' \' || last_name = ?', name])
self.find(:all, :conditions => ['(first_name || \' \' || last_name LIKE ?) OR (first_name || \' \' || middle_names || \' \' || last_name LIKE ?)', "%#{name}%", "%#{name}%"])

Answer 2

谷歌搜索可能有所帮助：http://www.google.com/search?q=sqlite+concat

在SQLite中，concat运算符是||。并且为了更容易阅读带有单引号'的字符串，我会用双引号"将这些字符串括起来，所以你不需要那么多的转义：

self.find(:first, :conditions => ["first_name || ' ' || middle_names || ' ' || last_name = ?", name])

self.find(:all, :conditions => ["(first_name || ' ' || last_name LIKE ?) OR (first_name, ' ', middle_names || ' ' || last_name LIKE ?)", "%#{name}%", "%#{name}%"])