(ns db-example
(:use [clojure.contrib.sql :only (with-connection with-query-results)] )
(:import (java.sql DriverManager)))
;; need this to load the sqlite3 driver (as a side effect of evaluating the expression)
(Class/forName "org.sqlite.JDBC")
(def +db-path+ "...")
(def +db-specs+ {:classname "org.sqlite.JDBC",
:subprotocol "sqlite",
:subname +db-path+})
(def +transactions-query+ "select * from my_table")
(with-connection +db-specs+
(with-query-results results [+transactions-query+]
;; results is an array of column_name -> value maps
))
最佳答案
您实际上必须从 with-query-results
宏中返回一些内容。因为绑定(bind)到 results
的 seq 是惰性的,所以让我们使用它:
(with-connection +db-specs+
(with-query-results results [+transactions-query+]
(doall results)))
这是使用 clojure.contrib.sql 时的常见模式,不依赖于 SQLite JDBC 适配器。
顺便说一句,我从来不需要手动执行 (Class/forName driver-class-str)
,这显然是您的 Java 习惯。驱动程序加载在 contrib.sql 的底层某处。
关于sqlite - 如何在 Clojure 中访问 SQLite 数据库?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/1480162/