Clojure Q&A - Recent questions tagged sql

Why i get "No suitable driver found for jdbc:://127.0.0.1/" ?

Mon, 26 Sep 2022 21:45:00 +0000

Java version :

openjdk 18.0.2-ea 2022-07-19
OpenJDK Runtime Environment (build 18.0.2-ea+9-Ubuntu-222.04)
OpenJDK 64-Bit Server VM (build 18.0.2-ea+9-Ubuntu-222.04, mixed mode, sharing)

but when i start the nREPL in my text editor, it's says :

Starting nREPL server...
/usr/lib/jvm/java-11-openjdk-amd64/bin/java ...

Dependencies :

:dependencies [[org.clojure/clojure "1.11.1"]
               [com.github.seancorfield/next.jdbc "1.3.834"]
               [org.postgresql/postgresql "42.5.0"]
               [com.layerware/hugsql "0.5.3"]]

code :

(def db
    {:classname "org.postgresql.Driver"
     :subprotocol "postgresql"
     :subname "reporting"
     :user "admin"
     :password "admin"})

(defn add-user-transaction [users]
  (jdbc/with-transaction [t-conn db]
                         (if-not (find-user t-conn {:id (:id users)})
                           (add-user! t-conn users))))

Everything works normal with that configuration, but only when i evaluate

(add-user-transaction {:id "cheryl"
                   :pass "Cheryl"})

the error appears.

It's asked in Clojure: Execution error (SQLException) at java.sql.DriverManager/getConnection (DriverManager.java:702) and already have answered, but the only answer in there is using :deps or deps.edn (as far i know, this is Maven repository), so how about leiningen? Or did i miss something about leiningen and Maven?
And i even restarting my pc, text editor, and nREPL but nothing change.

Why i get the "Could not locate hugsql/core__init.class, hugsql/core.clj or hugsql/core.cljc on classpath." ?

Mon, 26 Sep 2022 16:46:09 +0000

It's happen when i load the huqsql namespace into nREPL and then the error is appears to be something like this :

Syntax error (FileNotFoundException) compiling at (src/db_examples/hugsql.clj:1:1).
Could not locate hugsql/core__init.class, hugsql/core.clj or hugsql/core.cljc on classpath.

dependencies :

[[org.clojure/clojure "1.10.1"]
             [seancorfield/next.jdbc "1.1.613"]
             [org.postgresql/postgresql "42.2.8"]
             [com.layerware/hugsql "0.5.3"]
             [hugsql-next-jdbc "0.1.3"]]

the namespace :

(ns db-examples.hugsql

(:require [db-examples.core :refer [db]]
            [next.jdbc :as jdbc]
            [hugsql.core :as hugsql]))

(hugsql/def-db-fns "resources/users.sql")

set the query timeout on a SQL query

Wed, 19 Feb 2020 21:13:46 +0000

We have a SQL query that runs for 300 seconds sometimes. This slows down everything, and we would prefer to stop and throw an error after 30 seconds.

In Java, there is a Statement.setQueryTimeout() function where we can set the timeout to 30 seconds.

What is the best way to set this with our CLojure system?

FYI: We are also using honeysql.

How do you approach data (database) modeling in Clojure?

Thu, 29 Aug 2019 07:21:08 +0000

Hello everyone!

Recently i decided to create a copy of a moderate-sized project (which is written in Java with Spring Boot and Hibernate) in Clojure. And i wonder how to model data, and models, and relations in Clojure in idiomatic way?

I don't think it necessarily should be objects or ORM, but i do think that there should be some kind of a schema of DB or data spec reflected in code (so a developer can know what to query from database and what to expect to come from that query).

So, what my options are?

EDIT: As for now, database is PostgeSQL

Thanks!

EDIT2: Thank you all for your answers, they are very helpful and i definitely able to solve my problem now!