如何让 emacs sql-mode 使用 mysql 配置文件 (.my.cnf)？

Question

当我在 bash 提示符下键入mysql dbname时，我会自动使用.my.cnf文件中包含的username 、 password和host信息连接到数据库dbname 。

当我在 emacs 中使用Mx sql-mysql时，我再次被要求提供所有这些信息。

有没有办法让 emacs sql 模式使用我的.my.cnf文件中的信息？

Answer 1

我认为这是不可能的，但您可以在模式配置本身中设置此类内容：

(setq sql-connection-alist
'((pool-a
(sql-product 'mysql)
(sql-server "1.2.3.4")
(sql-user "me")
(sql-password "mypassword")
(sql-database "thedb")
(sql-port 3306))
(pool-b
(sql-product 'mysql)
(sql-server "1.2.3.4")
(sql-user "me")
(sql-password "mypassword")
(sql-database "thedb")
(sql-port 3307))))

(defun sql-connect-preset (name)
  "Connect to a predefined SQL connection listed in `sql-connection-alist'"
  (eval `(let ,(cdr (assoc name sql-connection-alist))
    (flet ((sql-get-login (&rest what)))
      (sql-product-interactive sql-product)))))

(defun sql-pool-a ()
  (interactive)
  (sql-connect-preset 'pool-a))

看看 这篇文章了解更多信息。

Answer 2

当然有可能。 不过还是挺牵强的。

大致步骤如下：

1. 使用ini.el读取和解析 ini 文件。
2. 将不同的主机配置与客户端配置合并，因为后者是全局应用的。
3. 将每个主机转换为适合sql-connection-alist格式
4. sql-connection-alist
5. 使用Mx sql-connect （自动完成！）

以下代码还包含一个 .pgpass 解析器，以防万一。 您会注意到实现更简单。

;;; .pgpass parser
(defun read-file (file)
  "Returns file as list of lines."
  (with-temp-buffer
    (insert-file-contents file)
    (split-string (buffer-string) "\n" t)))

(defun pgpass-to-sql-connection (config)
  "Returns a suitable list for sql-connection-alist from a pgpass file."
          (let ((server (lambda (host port db user _pass)
                          (list
                           (concat db ":" user ":" port ":" host)
                           (list 'sql-product ''postgres)
                           (list 'sql-server host)
                           (list 'sql-user user)
                           (list 'sql-port (string-to-number port))
                           (list 'sql-database db))))
                (pgpass-line (lambda (line)
                               (apply server (split-string line ":" t)))))
            (mapcar pgpass-line config)))

;;; .my.cnf parser
;;; Copied verbatim from https://github.com/daniel-ness/ini.el/blob/master/ini.el
(defun ini-decode (ini_text) 
  ;; text -> alist
  (interactive)
  (if (not (stringp ini_text))
      (error "Must be a string"))
  (let ((lines (split-string ini_text "\n"))
    (section)
    (section-list)
    (alist))
    (dolist (l lines)
      ;; skip comments
      (unless (or (string-match "^;" l)
          (string-match "^[ \t]$" l))
    ;; catch sections
    (if (string-match "^\\[\\(.*\\)\\]$" l)
        (progn 
          (if section
          ;; add as sub-list
          (setq alist (cons `(,section . ,section-list) alist))
        (setq alist section-list))
          (setq section (match-string 1 l))
          (setq section-list nil)))
          ;; catch properties
          (if (string-match "^\\([^\s\t]+\\)[\s\t]*=[\s\t]*\\(.+\\)$" l)
          (let ((property (match-string 1 l))
            (value (match-string 2 l)))
            (progn 
              (setq section-list (cons `(,property . ,value) section-list)))))))
    (if section
    ;; add as sub-list
    (setq alist (cons `(,section . ,section-list) alist))
      (setq alist section-list))
    alist))

(defun read-ini (file)
  "Returns ini file as alist."
  (with-temp-buffer
    (insert-file-contents file)
    (ini-decode (buffer-string))))

(defun filter-alist (wanted-members alist)
  "Returns a copy of given alist, with only fields from wanted-members."
  (let ((result nil)
        (add-if-member (lambda (elt)
                         (when (member (car elt) wanted-members)
                           (add-to-list 'result elt t)))))
    (mapc add-if-member alist)
    result))

(defun merge-alist (original override)
  "Returns a union of original and override alist. On key conflict, the latter wins."
  (let ((result (copy-alist override))
        (add (lambda (elt)
               (setq result (add-to-list
                             'result elt t
                             (lambda (left right) (equal (car left) (car right))))))))
    (mapc add original)
    result))
    
(defun parse-mycnf-hosts (file-path)
  "Returns list of hosts with clients' section applied to all hosts."
  (let ((hosts nil)
        (global nil)
        (fields '("user" "host" "database" "password" "port"))
        (section-parse (lambda(section)
                         (if (equal (car section) "client")
                             (setq global (filter-alist fields (cdr section)))
                           (let ((host (car section))
                                 (config (filter-alist fields (cdr section))))
                             (when config (add-to-list 'hosts (cons host config) t))))))
        (merge-host-with-global (lambda (host)
                                  (cons (car host) (merge-alist global (cdr host))))))
    (mapc section-parse (read-ini file-path))
    (mapcar merge-host-with-global hosts)))

(defun mycnf-to-sql-connection (config)
  (let ((add-sql-product
     (lambda (config)
       (let ((head (car config))
             (tail (cdr config)))
         (cons head (append tail (list (list 'sql-product ''mysql)))))))
    (parse-keys-and-values
     (lambda (config)
       (let ((head (car config))
             (tail (cdr config)))
         (cons
          head
          (mapcar
           (lambda (element)
            (let ((key (car element))
                  (value (cdr element)))
              (cond ((equal key "host") (list 'sql-server value))
                    ((equal key "port") (list 'sql-port (string-to-number value)))
                    ((equal key "user") (list 'sql-user value))
                    ((equal key "password") (list 'sql-password value))
                    ((equal key "database") (list 'sql-database value))
                    (t (error (format "Unknown key %s" key))))))
           tail))))))
  (mapcar add-sql-product (mapcar parse-keys-and-values config))))

;;; Actually populating sql-connection-alist
(setq sql-connection-alist
      (append
       (mycnf-to-sql-connection (parse-mycnf-hosts "~/.my.cnf"))
       (pgpass-to-sql-connection (read-file "~/.pgpass"))
       ))

使用以下.my.cnf ：

[client]
user=me

[host1]
database=db1
host=db.host1.com

[host2]
database=db2
user=notme
host=db.host2.com

执行表达式(mycnf-to-sql-connection (parse-mycnf-hosts "~/.my.cnf"))给了我（漂亮的手工打印）：

(("host2" ((sql-server "db.host2.com")
           (sql-user "notme")
           (sql-database "db2")))
 ("host1" ((sql-server "db.host1.com")
           (sql-database "db1")
           (sql-user "me"))))

最后，不要使用Mx sql-mysql ，而是使用Mx sql-connect ，您将能够使用别名进行连接，并自动完成。

Answer 3

为此，我们需要“欺骗” sql-mode 运行mysql --login-path=some-connection-name some-db-name （ --login-path是 sql-mode 不通过的参数默认。）

通过（默认情况下存储在.mylogin.cnf ）在 sql 端创建您的命名连接：

mysql_config_editor set --login-path=wow --host=127.0.0.1 --port=3306 --user=root --password

然后在 emacs 端标记连接（在你的init.el ）：

(setq sql-connection-alist
  '((wow-local
     (sql-product 'mysql)
     (sql-mysql-options '("--login-path=wow")) ; Note: use the login-path specified earlier
     (sql-server "") ; Note: All of these empty string parameters prevent being prompted for these values and are ignored.
     (sql-user "")
     (sql-password "")
     (sql-database "wowza"))
    (wow-local-test
     (sql-product 'mysql)
     (sql-mysql-options '("--login-path=wow")) ; Note: You can have multiple connections using the same login-path just with different parameters
     (sql-server "")
     (sql-user "")
     (sql-password "")
     (sql-database "wowza-test"))
    (production
     (sql-product 'mysql)
     (sql-mysql-options '("--login-path=production"))
     (sql-server "")
     (sql-port 0) ; Note: 0 ignores, anything else overrides your .cnf
     (sql-user "")
     (sql-password "")
     (sql-database "wowza_prod"))))

最后，我们创建了 sql 连接，并在 emacs 端标记了我们的连接，我们可以运行Mx sql-connect ，然后它会提示您选择一个可爱的连接。

笔记：

• 设置 emacs 变量sql-mysql-options允许您使用 .mylogin.cnf 文件中定义的连接（其他 .cnf 文件上的 YMMV）（您也可以使用它来传递您想要的任何 mysql 参数）
• 将sql-server 、 sql-user等设置为空字符串可防止提示输入所述值
• 将sql-server 、 sql-user等设置为空字符串以外的任何内容将覆盖 .cnf 中设置的值
• 请参阅sql.el文件中的Mx (describe-variable sql-mysql-options)和Mx (describe-function sql-comint-mysql)以sql.el有关忽略参数周围逻辑的更多详细信息。

TLDR：使用sql-mysql-options和--login-path=<your-login-path>魔法

Answer 4

只需点击返回，默认情况下它会被选中。