Neo4J Support

Dockerfile

@@ -8,7 +8,7 @@ WORKDIR /go/src/github.com/golang-migrate/migrate
 COPY . ./
 
 ENV GO111MODULE=on
-ENV DATABASES="postgres mysql redshift cassandra spanner cockroachdb clickhouse mongodb sqlserver firebird"
+ENV DATABASES="postgres mysql redshift cassandra spanner cockroachdb clickhouse mongodb sqlserver firebird neo4j"
 ENV SOURCES="file go_bindata github github_ee aws_s3 google_cloud_storage godoc_vfs gitlab"
 
 RUN go build -a -o build/migrate.linux-386 -ldflags="-s -w -X main.Version=${VERSION}" -tags "$DATABASES $SOURCES" ./cmd/migrate

database/neo4j/README.md

@@ -0,0 +1,11 @@
+# neo4j
+
+`bolt://user:password@host:port/`
+
+| URL Query  | WithInstance Config | Description |
+|------------|---------------------|-------------|
+| `user` | Contained within `AuthConfig` | The user to sign in as |
+| `password` | Contained within `AuthConfig` | The user's password | 
+| `host` | | The host to connect to. Values that start with / are for unix domain sockets. (default is localhost) |
+| `port` | | The port to bind to. (default is 7687) |
+|  | `MigrationsLabel` | Name of the migrations node label |

database/neo4j/TUTORIAL.md

@@ -0,0 +1,97 @@
+## Create migrations
+Let's create nodes called `Users`:
+```
+migrate create -ext cypher -dir db/migrations -seq create_user_nodes
+```
+If there were no errors, we should have two files available under `db/migrations` folder:
+- 000001_create_user_nodes.down.cypher
+- 000001_create_user_nodes.up.cypher
+
+Note the `cypher` extension that we provided.
+
+In the `.up.cypher` file let's create the table:
+```
+CREATE (u1:User {name: "Peter"})
+CREATE (u2:User {name: "Paul"})
+CREATE (u3:User {name: "Mary"})
+```
+And in the `.down.sql` let's delete it:
+```
+MATCH (u:User) WHERE u.name IN ["Peter", "Paul", "Mary"] DELETE u
+```
+Ideally your migrations should be idempotent. You can read more about idempotency in [getting started](GETTING_STARTED.md#create-migrations)
+
+## Run migrations
+```
+migrate -database ${NEO4J_URL} -path db/migrations up
+```
+Let's check if the table was created properly by running `bin/cypher-shell -u neo4j -p password`, then `neo4j> MATCH (u:User)`
+The output you are supposed to see:
+```
++-----------------------------------------------------------------+
+| u                                                               |
++-----------------------------------------------------------------+
+| (:User {name: "Peter")                                          |
+| (:User {name: "Paul")                                           |
+| (:User {name: "Mary")                                           |
++-----------------------------------------------------------------+
+```
+Great! Now let's check if running reverse migration also works:
+```
+migrate -database ${NEO4J_URL} -path db/migrations down
+```
+Make sure to check if your database changed as expected in this case as well.
+
+## Database transactions
+
+To show database transactions usage, let's create another set of migrations by running:
+```
+migrate create -ext cypher -dir db/migrations -seq add_mood_to_users
+```
+Again, it should create for us two migrations files:
+- 000002_add_mood_to_users.down.cypher
+- 000002_add_mood_to_users.up.cypher
+
+In Neo4j, when we want our queries to be done in a transaction, we need to wrap it with `:BEGIN` and `:COMMIT` commands.
+Migration up:
+```
+:BEGIN
+
+MATCH (u:User)
+SET u.mood = "Cheery"
+
+:COMMIT
+```
+Migration down:
+```
+:BEGIN
+
+MATCH (u:User)
+SET u.mood = null
+
+:COMMIT
+```
+
+## Optional: Run migrations within your Go app
+Here is a very simple app running migrations for the above configuration:
+```
+import (
+	"log"
+
+	"github.com/golang-migrate/migrate/v4"
+	_ "github.com/golang-migrate/migrate/v4/database/neo4j"
+	_ "github.com/golang-migrate/migrate/v4/source/file"
+)
+
+func main() {
+	m, err := migrate.New(
+		"file://db/migrations",
+		"bolt://neo4j:password@localhost:7687/")
+	if err != nil {
+		log.Fatal(err)
+	}
+	if err := m.Up(); err != nil {
+		log.Fatal(err)
+	}
+}
+```

database/neo4j/neo4j.go

@@ -1,3 +1,5 @@
+// +build cgo
+
 package neo4j
 
 import (
@@ -13,7 +15,6 @@ import (
 
 func init() {
 	db := Neo4j{}
-	database.Register("bolt", &db)
 	database.Register("neo4j", &db)
 }
 
@@ -25,7 +26,7 @@ var (
 
 type Config struct {
 	AuthToken       neo4j.AuthToken
-	URL             string
+	URL             string // if using WithInstance, don't provide auth in the URL, it will be ignored
 	MigrationsLabel string
 }
 
@@ -66,9 +67,10 @@ func (n *Neo4j) Open(url string) (database.Driver, error) {
 	}
 	password, _ := uri.User.Password()
 	authToken := neo4j.BasicAuth(uri.User.Username(), password, "")
+	uri.User = nil
 
 	return WithInstance(&Config{
-		URL:             url,
+		URL:             uri.String(),
 		AuthToken:       authToken,
 		MigrationsLabel: DefaultMigrationsLabel,
 	})
@@ -182,7 +184,7 @@ func (n *Neo4j) Drop() error {
 	}
 	defer session.Close()
 
-	_, err = session.Run("MATCH (n) DETACH DELETE n", map[string]interface{}{})
+	_, err = session.Run("MATCH (n) DETACH DELETE n", nil)
 	return err
 }
 

database/neo4j/neo4j_test.go

@@ -1,3 +1,5 @@
+// +build cgo
+
 package neo4j
 
 import (
@@ -101,6 +103,6 @@ func TestMigrate(t *testing.T) {
 		if err != nil {
 			t.Fatal(err)
 		}
-		dt.TestMigrate(t, m, []byte("MATCH a RETURN a"))
+		dt.TestMigrate(t, m)
 	})
 }