活动记录查询 select_all，prepared statement答案

【问题标题】：Active record query select_all, prepared statement活动记录查询 select_all，prepared statement
【发布时间】：2013-07-11 16:16:14
【问题描述】：

我正在尝试编写如下准备好的语句：

@fofs = FileOrFolder.connection.select_all("select * from newtestdocB.file_or_folders where name like","%#{params[:search]}%")

原来是mysql控制台上的一个错误查询。不接受变量 %#{params[:search]}% 的值进行查询

请更正我的查询...

控制台消息：

Parameters: {"search"=>"do", "cluster_id"=>"2", "datasetid"=>"1", "id"=>"1"}
  %do% (0.2ms)  select * from newtestdocB.file_or_folders where name like

ActiveRecord::StatementInvalid (Mysql2::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1: select * from newtestdocB.file_or_folders where name like):

【问题讨论】：

标签： ruby-on-rails ruby-on-rails-3 activerecord ruby-on-rails-3.1 ruby-on-rails-3.2

【解决方案1】：

Try a placeholder ?

"select * from newtestdocB.file_or_folders where name like ?","%#{params[:search]}%"

见上述语句中的问号，将由逗号后面的参数填写。

如果上面的语句不起作用，这个必须起作用，使用“+”连接，注意“like”旁边的空格

sql = "select * from newtestdocB.file_or_folders where name like <<space>>" + "%#{params[:search]}%"

FileOrFolder.connection.select_all(sql)

【讨论】：

它不工作......它把它作为一个完整的字符串和类似的参数它不在引号中......输出sql：select * from newtestdocB.file_or_folders where name like %d% .................... %d% 不在引号中 ...
"select * from newtestdocB.file_or_folders where name like >" + "%#{params[:search]}%" ...也不工作！
"select * from newtestdocB.file_or_folders where name like " + "%#{params[:search]}%" ..here..don't give >, 我的意思是留下文字空间...
...也试过了...... dint 工作......当我在控制台中签入时，它会在“喜欢”之后停止 select * from newtestdocB.file_or_folders where name like
则表示 params[:search] 为 nil，就像这里...1.9.3-p385 :003 > "sadf " + "#{nil}" => "sadf "跨度>