Clojure.contrib.sql：如何将select语句的结果检索到可以随时访问的向量中？

Question

For example, in this query:

(Clojure.contrib.sql/with-query-results rows ["SELECT count(*) from tableName"] (doseq [record rows] (println (vals record))))

It seems that record and rows don't exist outside this scope but I want it to exist anytime for me access.

Update: I tried the following lines of code

(def asdf [])
(sql/with-connection db

(sql/with-query-results rows ["SELECT * FROM tableName"] (doseq [record rows] (def asdf (conj asdf record)))))

(println asdf)

Why does the print statement of asdf above return empty when I added the rows to it in the sql statement?

Answer 1

You seem to lack a basic understanding of Clojure's underlying principles, in particular immutable data structures. Your conj call doesn't modify the var asdf -- a var is not a variable. You could do something like the following (untested)

(def asdf 
    (sql/with-connection db
         (doall (sql/with-query-results rows ["SELECT * FROM tableName"]))))

to store the result directly as the value of asdf , but this is probably not really what you want. Get familiar with Clojure's take on functional programming instead.