Connect to a Database

1. Get a Database Adapter

To connect to a database you need an adapter. Use go get to get one, like this:

go get -u github.com/upper/db/v4/adapter/{$ADAPTER}

Where $ADAPTER could be any of the following:

• cockroachdb: for CockroachDB
• mongo: for MongoDB
• mysql: for MySQL
• postgresql: for PostgreSQL
• ql: for QL
• sqlite: for SQLite

For instace, if you’d like to use the cockroachdb adapter you’d first run:

go get -u github.com/upper/db/v4/adapter/cockroachdb

to get the adapter, and then you can include it in the source code of your project:

import (
  "github.com/upper/db/v4/adapter/cockroachdb"
)

2. Configure a Database Connection

Set the database credentials using the ConnectionURL type provided by the adapter:

import (
  "github.com/upper/v4/adapter/cockroachdb"
)

var settings = cockroachdb.ConnectionURL{
  Database: `booktown`,
  Host:     `cockroachdb.demo.upper.io`,
  User:     `demouser`,
  Password: `demop4ss`,
}

Note that the ConnectionURL (which satisfies the db.ConnectionURL interface) varies from one database engine to another. The connection properties required by each adapter are explained in detail here.

3. Attempt to Establish a Connection

Use the Open function to establish a connection with the database server:

sess, err := cockroachdb.Open(settings)
...

4. Set the Connection to Close

Set the database connection to close automatically after completing all tasks. Use Close and defer:

defer sess.Close()