dh - A simple Database Deployment Handler in Go

dh is a reaction to DBIx::Class::DeploymentHandler, a database migration system I built in in 2010. While the original DBICDH was built on top of an existing ORM and schema transformation tooling, this version is intentionally simpler, and allows users to drop in ORM support if needed.

Getting Started

The primary users of this program are expected to be Go programmers, using dh as a library. First, create your deployment directory:

mkdir -p dh/001
cat <<EOF > dh/001/dh.sql
CREATE TABLE users (
        "id",
        "name",
        "email"
);
EOF

cat <<EOF > dh/001/shortlinks.sql
CREATE TABLE shortlinks (
        "from",
        "to",
        "deleted"
        PRIMARY KEY ("from")
);
EOF

cat <<EOF > dh/001/history.sql
CREATE TABLE IF NOT EXISTS history (
        "from",
        "to",
        "when",
        "who"
);
EOF

Add that directory to your migration plan:

echo 000-sqlite > dh/plan.txt
echo 001       >> dh/plan.txt

Now let's create a migration to add another column:

mkdir dh/002

cat <<SQL >dh/002/shortlinks.sql
ALTER TABLE shortlinks ADD COLUMN "description" NOT NULL DEFAULT ''
SQL

cat <<SQL > dh/002/history.sql
ALTER TABLE history ADD COLUMN "description" NOT NULL DEFAULT ''
SQL

And add it to your plan:

echo 002 >> dh/plan.txt

And here's how you'd use it:

dbh := sql.Connect(...)
m := dh.NewMigrator()
if err := m.MigrateOne(dbh, dh.DHMigrations, "000-sqlite"); err != nil {
        panic(err)
}
if err := m.MigrateAll(dbh, os.DirFS("dh")); err != nil {
        return err
}

Out of the box dh can apply SQL or lists of SQL from JSON files, but the migration interface is extensible so you could wire up gopher-lua to do more advanced migrations.

frioux/dh

dh - A simple Database Deployment Handler in Go

Getting Started