使用PostgreSQL使用ActiveRecord准备和执行语句 [英] Prepare and execute statements with ActiveRecord using PostgreSQL

查看：174 发布时间：2020/6/1 19:42:37 ruby-on-rails activerecord insert prepared-statement

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我正在尝试使用ActiveRecord通过准备好的语句插入值。但是，每次我尝试：

I am trying to insert values via a prepared statement using ActiveRecord. However, everytime I try:

conn = ActiveRecord::Base.connection
conn.prepare "SELECT * from sampletable where id = $1"
conn.execute 3

在第二条语句之后，我得到：

After the second statement, I get:

NoMethodError: undefined method `prepare' for
#<ActiveRecord::ConnectionAdapters::PostgreSQLAdapter:0x000001027442c8>

我该怎么办？我正在运行Rails 3.2.1和Ruby 1.9.2

What should I do? I'm running Rails 3.2.1 and Ruby 1.9.2

更新：

我解决了这个问题。感谢您的答复，但不适用于PostgreSQL。这样做的方法是：

I solved the problem. Thanks for the response, but it didn't work for PostgreSQL. The way to do it is:

stmt = "SELECT * from sampletable where id = $1 and name = $2"
values = [ { value: 1}, { value: "henry" } ]

其中，值是哈希数组，每个哈希指定一个值，$ 1绑定到第0个哈希，$ 2绑定到数组中的第2个哈希，依此类推

where values is an array of hashes, each specifying a value, $1 is bound to the 0th hash, $2 is bound to the 2nd hash in the array and so on

con = PG::Connection.new(:dbname => "development_DB")
con.prepare("insert", stmt)
con.exec_prepared("insert", values)
con.close()

女士们，先生们，这行得通！

And this, ladies and gentlemen, works!

从已编辑的问题正文中复制答案，以便从未答复过滤器中删除此问题：

Copying the answer from the edited question body, in order to remove this question from the "Unanswered" filter:

我解决了这个问题。感谢您的回应，但不适用于
PostgreSQL。这样做的方法是：

I solved the problem. Thanks for the response, but it didn't work for PostgreSQL. The way to do it is:

stmt = "SELECT * from sampletable where id = $1 and name = $2"
values = [ { value: 1}, { value: "henry" } ]

其中，值是一个哈希数组，每个哈希指定一个值，$ 1是
绑定到第0个哈希，$ 2绑定到数组中的第2个哈希，因此
on

where values is an array of hashes, each specifying a value, $1 is bound to the 0th hash, $2 is bound to the 2nd hash in the array and so on

con = PG::Connection.new(:dbname => "development_DB")
con.prepare("insert", stmt)
con.exec_prepared("insert", values)
con.close()

女士们，先生们，工作！

And this, ladies and gentlemen, works!

〜每个 alalani

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