add mysql commandline example (#399)

examples/mysql_cmdline.clj

@@ -0,0 +1,44 @@
+#!/usr/bin/env bb
+
+;; Simple example of accessing mysql's data via the command line, then turnning around and dumping that data as a table.
+
+;; (map2arg-- mdb "-h" :host) => "-hlocalhost"
+(defn map2arg-
+  "Create mysql command line argument from connection map"
+  [mdb arg key]
+  (str arg (get mdb key)))
+
+(defn make-mysql-command-
+  "Create mysql command line using connection map and statement"
+  [mdb statement]
+  ["mysql" (map2arg- mdb "-h" :host) (map2arg- mdb "-u" :user) (map2arg- mdb "-p" :password) (:dbname mdb) "--column-names" "-e" statement ])
+
+(defn query
+  "Executes a query agatinst the command line mysql. Return is a vector of maps with populated with each row."
+  [ mdb statement ]
+  (let [
+        mysql-command (make-mysql-command- mdb statement)
+        table-as-str (:out (apply shell/sh mysql-command))
+        table-as-lines (str/split-lines table-as-str)
+        table-headers (str/split (first table-as-lines) #"\t")
+        table-as-maps (map #(zipmap table-headers (str/split %1 #"\t")) (rest table-as-lines))
+        ]
+    table-as-maps
+    ))
+
+;; Typical connection specifier
+(def mdb {:dbtype "mysql" :dbname "corp" :host "localhost" :user "dba" :password "dba"})
+
+;; extracted rows
+(def rows (query mdb "select TABLE_NAME, ENGINE from information_schema.tables limit 3"))
+
+;; display the data!
+(clojure.pprint/print-table rows)
+
+
+;; Tells emacs to jump into clojure mode.
+;; Local Variables:
+;; mode: clojure
+;; End:
+
+