Question

如何在MySQL中为insert和select查询创建预准备语句？我正在使用MySQL2 gem，我的连接对象如下所示：

 con = Mysql2::Client.new(:host => "#{ENV['DB_HOST']}", :port => '3306', :username => "#{ENV['DB_UNAME']}", :password => "#{ENV['DB_PWD']}", :database => 'dbname')

Answer 1

不幸的是，mysql2 gem尚未准备好语句支持。贡献者计划在不久的将来添加这样的功能，正如我们从Pull Request讨论中看到的那样：

https://github.com/brianmario/mysql2/pull/289

如果您必须在您的应用程序中准备好语句，我建议您阅读Sequel，它对准备好的语句和绑定变量有非常好的支持：

https://github.com/jeremyevans/sequel

http://sequel.jeremyevans.net/rdoc/files/doc/prepared_statements_rdoc.html

<强>更新

正如@lulalala所述，从版本 0.4.0开始 MySQL2 gem支持预备语句：

statement = @client.prepare("SELECT * FROM users WHERE login_count = ?")
result1 = statement.execute(1) # Binds the value 1 to the placeholder 
result2 = statement.execute(2) # Binds the value 2 to the placeholder

statement = @client.prepare("SELECT * FROM users WHERE last_login >= ? AND location LIKE ?")
result = statement.execute(1, "CA") # Binds 1 and 'CA' to the placeholders, respectively

我希望有所帮助。

Answer 2

您也可以使用mysql2-cs-bind gem，它是mysql2的一个瘦包装，它添加了预备语句功能： https://github.com/tagomoris/mysql2-cs-bind

它提供了接受语句参数的xquery方法：

require 'mysql2-cs-bind'
client = Mysql2::Client.new(...)
client.xquery('SELECT x,y,z FROM tbl WHERE x=? AND y=?', val1, val2) #=> Mysql2::Result

使用带有MySQL2 gem的预处理语句？

2 个答案: