Clojure操作mysql

在Eclipse中新建一个Clojure工程clj01

clojure 操作mysql需要依赖mysql-connector-java、clojure-contrib与java.jdbc三个jar包。

project.clj配置信息如下：配置完:dependencies 保存，系统会自动下载所配置的jar包信息。

(defproject clj01 "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [
                 [org.clojure/clojure "1.5.1"]
                 [org.clojure/java.jdbc "0.2.3"]
                 [org.clojure/clojure-contrib "1.2.0"]
                 [mysql/mysql-connector-java "5.1.26"]
                 ])

新建mysql.clj

(ns clj01.mysql
  (:require [clojure.java.jdbc :as sql]))

;配置参数
(def mysql-db{
              :classname "com.mysql.jdbc.Driver"
              :subprotocol "mysql"
              :subname "//127.0.0.1:3306/test"
              :user "root"
              :password "" })

;链接数据库
(sql/with-connection mysql-db)

;插入数据
(sql/with-connection mysql-db
  (sql/insert-records :user
                      {:name "测试1" :age 25}
                      {:name "测试2" :age 26}))

;删除记录
(sql/with-connection mysql-db
  (sql/delete-rows :user ["id > ?" 8]))

;更新记录
(sql/with-connection mysql-db
  (sql/update-values :user
                     ["id = ?" 8]
                     {:name "测试" :age 35}))

;查询记录
(println (sql/with-connection mysql-db
           (sql/with-query-results rows
             ["select id,name,age from user where age > ?" 25]
             (dorun (map #(println %) rows)))))

表结构：

mysql> desc user;
+-------+-------------+------+-----+---------+----------------+
| Field | Type        | Null | Key | Default | Extra          |
+-------+-------------+------+-----+---------+----------------+
| id    | int(11)     | NO   | PRI | NULL    | auto_increment |
| name  | varchar(10) | YES  |     | NULL    |                |
| age   | int(11)     | YES  |     | NULL    |                |
+-------+-------------+------+-----+---------+----------------+

问题：在第一次运行代码时控制台提示如下异常：

otFoundException Could not locate clojure/java/jdbc__init.class or clojure/java/jdbc.clj on classpath:   clojure.lang.RT.load (RT.java:443)

重启Eclipse之后问题解决，好像是Eclipse工具问题引起的。