Add Up command to create database and migrate

commands.go

@@ -14,6 +14,32 @@ import (
 	"time"
 )
 
+// UpCommand creates the database (if necessary) and runs migrations
+func UpCommand(ctx *cli.Context) error {
+	u, err := GetDatabaseURL(ctx)
+	if err != nil {
+		return err
+	}
+
+	drv, err := driver.Get(u.Scheme)
+	if err != nil {
+		return err
+	}
+
+	// create database if it does not already exist
+	// skip this step if we cannot determine status
+	// (e.g. user does not have list database permission)
+	exists, err := drv.DatabaseExists(u)
+	if err == nil && !exists {
+		if err := drv.CreateDatabase(u); err != nil {
+			return err
+		}
+	}
+
+	// migrate
+	return MigrateCommand(ctx)
+}
+
 // CreateCommand creates the current database
 func CreateCommand(ctx *cli.Context) error {
 	u, err := GetDatabaseURL(ctx)

driver/driver.go

@@ -11,6 +11,7 @@ import (
 // Driver provides top level database functions
 type Driver interface {
 	Open(*url.URL) (*sql.DB, error)
+	DatabaseExists(*url.URL) (bool, error)
 	CreateDatabase(*url.URL) error
 	DropDatabase(*url.URL) error
 	CreateMigrationsTable(*sql.DB) error

driver/postgres/postgres.go

@@ -18,39 +18,66 @@ func (postgres Driver) Open(u *url.URL) (*sql.DB, error) {
 }
 
 // postgresExec runs a sql statement on the "postgres" database
-func (postgres Driver) postgresExec(u *url.URL, statement string) error {
+func (postgres Driver) openPostgresDB(u *url.URL) (*sql.DB, error) {
 	// connect to postgres database
 	postgresURL := *u
 	postgresURL.Path = "postgres"
 
-	db, err := postgres.Open(&postgresURL)
+	return postgres.Open(&postgresURL)
+}
+
+// CreateDatabase creates the specified database
+func (postgres Driver) CreateDatabase(u *url.URL) error {
+	name := shared.DatabaseName(u)
+	fmt.Printf("Creating: %s\n", name)
+
+	db, err := postgres.openPostgresDB(u)
 	if err != nil {
 		return err
 	}
 	defer db.Close()
 
-	// run statement
-	_, err = db.Exec(statement)
+	_, err = db.Exec(fmt.Sprintf("CREATE DATABASE %s",
+		pq.QuoteIdentifier(name)))
 
 	return err
 }
 
-// CreateDatabase creates the specified database
-func (postgres Driver) CreateDatabase(u *url.URL) error {
-	database := shared.DatabaseName(u)
-	fmt.Printf("Creating: %s\n", database)
-
-	return postgres.postgresExec(u, fmt.Sprintf("CREATE DATABASE %s",
-		pq.QuoteIdentifier(database)))
-}
-
 // DropDatabase drops the specified database (if it exists)
 func (postgres Driver) DropDatabase(u *url.URL) error {
-	database := shared.DatabaseName(u)
-	fmt.Printf("Dropping: %s\n", database)
+	name := shared.DatabaseName(u)
+	fmt.Printf("Dropping: %s\n", name)
 
-	return postgres.postgresExec(u, fmt.Sprintf("DROP DATABASE IF EXISTS %s",
-		pq.QuoteIdentifier(database)))
+	db, err := postgres.openPostgresDB(u)
+	if err != nil {
+		return err
+	}
+	defer db.Close()
+
+	_, err = db.Exec(fmt.Sprintf("DROP DATABASE IF EXISTS %s",
+		pq.QuoteIdentifier(name)))
+
+	return err
+}
+
+// DatabaseExists determines whether the database exists
+func (postgres Driver) DatabaseExists(u *url.URL) (bool, error) {
+	name := shared.DatabaseName(u)
+
+	db, err := postgres.openPostgresDB(u)
+	if err != nil {
+		return false, err
+	}
+	defer db.Close()
+
+	exists := false
+	err = db.QueryRow("SELECT true FROM pg_database WHERE datname = $1", name).
+		Scan(&exists)
+	if err == sql.ErrNoRows {
+		return false, nil
+	}
+
+	return exists, err
 }
 
 // HasMigrationsTable returns true if the schema_migrations table exists

driver/postgres/postgres_test.go

@@ -61,3 +61,36 @@ func TestCreateDropDatabase(t *testing.T) {
 		require.Equal(t, "pq: database \"dbmate\" does not exist", err.Error())
 	}()
 }
+
+func TestDatabaseExists(t *testing.T) {
+	d := postgres.Driver{}
+	u := testURL(t)
+
+	// drop any existing database
+	err := d.DropDatabase(u)
+	require.Nil(t, err)
+
+	// DatabaseExists should return false
+	exists, err := d.DatabaseExists(u)
+	require.Nil(t, err)
+	require.Equal(t, false, exists)
+
+	// create database
+	err = d.CreateDatabase(u)
+	require.Nil(t, err)
+
+	// DatabaseExists should return true
+	exists, err = d.DatabaseExists(u)
+	require.Nil(t, err)
+	require.Equal(t, true, exists)
+}
+
+func TestDatabaseExists_error(t *testing.T) {
+	d := postgres.Driver{}
+	u := testURL(t)
+	u.User = url.User("invalid")
+
+	exists, err := d.DatabaseExists(u)
+	require.Equal(t, "pq: role \"invalid\" does not exist", err.Error())
+	require.Equal(t, false, exists)
+}

main.go

@@ -35,20 +35,6 @@ func NewApp() *cli.App {
 	}
 
 	app.Commands = []cli.Command{
-		{
-			Name:  "migrate",
-			Usage: "Migrate to the latest version",
-			Action: func(ctx *cli.Context) {
-				runCommand(MigrateCommand, ctx)
-			},
-		},
-		{
-			Name:  "rollback",
-			Usage: "Rollback the most recent migration",
-			Action: func(ctx *cli.Context) {
-				runCommand(RollbackCommand, ctx)
-			},
-		},
 		{
 			Name:  "new",
 			Usage: "Generate a new migration file",
@@ -56,6 +42,13 @@ func NewApp() *cli.App {
 				runCommand(NewCommand, ctx)
 			},
 		},
+		{
+			Name:  "up",
+			Usage: "Create database (if necessary) and migrate to the latest version",
+			Action: func(ctx *cli.Context) {
+				runCommand(UpCommand, ctx)
+			},
+		},
 		{
 			Name:  "create",
 			Usage: "Create database",
@@ -70,6 +63,20 @@ func NewApp() *cli.App {
 				runCommand(DropCommand, ctx)
 			},
 		},
+		{
+			Name:  "migrate",
+			Usage: "Migrate to the latest version",
+			Action: func(ctx *cli.Context) {
+				runCommand(MigrateCommand, ctx)
+			},
+		},
+		{
+			Name:  "rollback",
+			Usage: "Rollback the most recent migration",
+			Action: func(ctx *cli.Context) {
+				runCommand(RollbackCommand, ctx)
+			},
+		},
 	}
 
 	return app