如何在 Elixir 字符串中显示单个反斜杠

Question

有人能告诉我如何在 Elixir

的 SQL 语句中添加一个反斜杠吗

iex(1)> sql = "select * from user limit 1 \G;" "select * from user limit 1 G;" iex(2)> sql = "select * from user limit 1 \G;" "select * from user limit 1 \G;"

我的 sql 语句中只需要 '\G'

$ elixir -v Elixir 1.1.0-dev

其实我想用mariaex库，但是还是不行

defmodule Customer do

    def main(args) do

        sql = "SELECT name FROM user limit 3 \G;"

        {:ok, p} = Mariaex.Connection.start_link(username: "root", password: "password", database: "user")

        res = Mariaex.Connection.query(p, sql )

        IO.inspect res
    end
end

当我执行代码时，它告诉我“\G”附近有语法错误

$ escript billutil
{:error,
 %Mariaex.Error{mariadb: %{code: 1064,
    message: "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 '\G' at line 1"},
  message: nil}}

请问我应该如何格式化字符串？

Answer 1

你的第二次尝试是正确的。您会在输出中看到两个反斜杠，因为它是经过检查的输出（打印为 Elixir 术语）。如果您尝试将 sql 打印到控制台，您会看到一个反斜杠：

iex(1)> IO.puts("select * from user limit 1 \G;")
select * from user limit 1 \G;

如何在 Elixir 字符串中显示单个反斜杠

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