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

Question

當我在 bash 提示符下鍵入mysql dbname時，我會自動使用.my.cnf文件中包含的username 、 password和host信息連接到數據庫dbname 。

當我在 emacs 中使用Mx sql-mysql時，我再次被要求提供所有這些信息。

有沒有辦法讓 emacs sql 模式使用我的.my.cnf文件中的信息？

Answer 1

我認為這是不可能的，但您可以在模式配置本身中設置此類內容：

(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 這篇文章了解更多信息。

Answer 2

當然有可能。 不過還是挺牽強的。

大致步驟如下：

1. 使用ini.el讀取和解析 ini 文件。
2. 將不同的主機配置與客戶端配置合並，因為后者是全局應用的。
3. 將每個主機轉換為適合sql-connection-alist格式
4. sql-connection-alist
5. 使用Mx sql-connect （自動完成！）

以下代碼還包含一個 .pgpass 解析器，以防萬一。 您會注意到實現更簡單。

;;; .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

執行表達式(mycnf-to-sql-connection (parse-mycnf-hosts "~/.my.cnf"))給了我（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 ，您將能夠使用別名進行連接，並自動完成。

Answer 3

為此，我們需要“欺騙” sql-mode 運行mysql --login-path=some-connection-name some-db-name （ --login-path是 sql-mode 不通過的參數默認。）

通過（默認情況下存儲在.mylogin.cnf ）在 sql 端創建您的命名連接：

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

然后在 emacs 端標記連接（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，我們創建了 sql 連接，並在 emacs 端標記了我們的連接，我們可以運行Mx sql-connect ，然后它會提示您選擇一個可愛的連接。

筆記：

• 設置 emacs 變量sql-mysql-options允許您使用 .mylogin.cnf 文件中定義的連接（其他 .cnf 文件上的 YMMV）（您也可以使用它來傳遞您想要的任何 mysql 參數）
• 將sql-server 、 sql-user等設置為空字符串可防止提示輸入所述值
• 將sql-server 、 sql-user等設置為空字符串以外的任何內容將覆蓋 .cnf 中設置的值
• 請參閱sql.el文件中的Mx (describe-variable sql-mysql-options)和Mx (describe-function sql-comint-mysql)以sql.el有關忽略參數周圍邏輯的更多詳細信息。

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

Answer 4

只需點擊返回，默認情況下它會被選中。