Create migration file with next version number

Fixes #25

README.md

@@ -37,38 +37,43 @@ Drivers:
     redshift
 
 Commands:
-    up                Migrate the DB to the most recent version available
+    up                   Migrate the DB to the most recent version available
-    up-to VERSION     Migrate the DB to a specific VERSION
+    up-to VERSION        Migrate the DB to a specific VERSION
-    down              Roll back the version by 1
+    down                 Roll back the version by 1
-    down-to VERSION   Roll back to a specific VERSION
+    down-to VERSION      Roll back to a specific VERSION
-    redo              Re-run the latest migration
+    redo                 Re-run the latest migration
-    status            Dump the migration status for the current DB
+    status               Dump the migration status for the current DB
-    version           Print the current version of the database
+    version              Print the current version of the database
-    create            Creates a blank migration template
+    create NAME [sql|go] Creates new migration file with next version
 
 Options:
     -dir string
         directory with migration files (default ".")
 
 Examples:
-    goose postgres "user=postgres dbname=postgres sslmode=disable" up
-    goose mysql "user:password@/dbname" down
     goose sqlite3 ./foo.db status
-    goose redshift "postgres://user:password@qwerty.us-east-1.redshift.amazonaws.com:5439/db" create init sql
+    goose sqlite3 ./foo.db create init sql
+    goose sqlite3 ./foo.db create add_some_column sql
+    goose sqlite3 ./foo.db create fetch_user_data go
+    goose sqlite3 ./foo.db up
+
+    goose postgres "user=postgres dbname=postgres sslmode=disable" status
+    goose mysql "user:password@/dbname" status
+    goose redshift "postgres://user:password@qwerty.us-east-1.redshift.amazonaws.com:5439/db" status
 ```
 ## create
 
-Create a new Go migration.
+Create a new SQL migration.
 
-    $ goose create AddSomeColumns
+    $ goose create add_some_column sql
-    $ goose: created db/migrations/20130106093224_AddSomeColumns.go
+    $ Created new file: 00001_add_some_column.sql
 
-Edit the newly created script to define the behavior of your migration.
+Edit the newly created file to define the behavior of your migration.
 
-You can also create an SQL migration:
+You can also create a Go migration, if you then invoke it with [your own goose binary](#go-migrations):
 
-    $ goose create AddSomeColumns sql
+    $ goose create fetch_user_data go
-    $ goose: created db/migrations/20130106093224_AddSomeColumns.sql
+    $ Created new file: 00002_fetch_user_data.go
 
 ## up
 

cmd/goose/main.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/pressly/goose"
 
+	// Init DB drivers.
 	_ "github.com/go-sql-driver/mysql"
 	_ "github.com/lib/pq"
 	_ "github.com/mattn/go-sqlite3"
@@ -95,23 +96,28 @@ Drivers:
     redshift
 
 Examples:
-    goose postgres "user=postgres dbname=postgres sslmode=disable" up
-    goose mysql "user:password@/dbname" down
     goose sqlite3 ./foo.db status
-    goose redshift "postgres://user:password@qwerty.us-east-1.redshift.amazonaws.com:5439/db" create init sql
+    goose sqlite3 ./foo.db create init sql
+    goose sqlite3 ./foo.db create add_some_column sql
+    goose sqlite3 ./foo.db create fetch_user_data go
+    goose sqlite3 ./foo.db up
+
+    goose postgres "user=postgres dbname=postgres sslmode=disable" status
+    goose mysql "user:password@/dbname" status
+    goose redshift "postgres://user:password@qwerty.us-east-1.redshift.amazonaws.com:5439/db" status
 
 Options:
 `
 
 	usageCommands = `
 Commands:
-    up                Migrate the DB to the most recent version available
+    up                   Migrate the DB to the most recent version available
-    up-to VERSION     Migrate the DB to a specific VERSION
+    up-to VERSION        Migrate the DB to a specific VERSION
-    down              Roll back the version by 1
+    down                 Roll back the version by 1
-    down-to VERSION   Roll back to a specific VERSION
+    down-to VERSION      Roll back to a specific VERSION
-    redo              Re-run the latest migration
+    redo                 Re-run the latest migration
-    status            Dump the migration status for the current DB
+    status               Dump the migration status for the current DB
-    version           Print the current version of the database
+    version              Print the current version of the database
-    create            Creates a blank migration template
+    create NAME [sql|go] Creates new migration file with next version
 `
 )

create.go

@@ -3,16 +3,86 @@ package goose
 import (
 	"database/sql"
 	"fmt"
-	"time"
+	"os"
+	"path/filepath"
+	"text/template"
 )
 
 // Create writes a new blank migration file.
 func Create(db *sql.DB, dir, name, migrationType string) error {
-	path, err := CreateMigration(name, migrationType, dir, time.Now())
+	migrations, err := CollectMigrations(dir, minVersion, maxVersion)
 	if err != nil {
 		return err
 	}
-	fmt.Println(fmt.Sprintf("Created %s migration at %s", migrationType, path))
 
+	// Initial version.
+	version := "00001"
+
+	if last, err := migrations.Last(); err == nil {
+		version = fmt.Sprintf("%05v", last.Version+1)
+	}
+
+	filename := fmt.Sprintf("%v_%v.%v", version, name, migrationType)
+
+	fpath := filepath.Join(dir, filename)
+	tmpl := sqlMigrationTemplate
+	if migrationType == "go" {
+		tmpl = goSQLMigrationTemplate
+	}
+
+	path, err := writeTemplateToFile(fpath, tmpl, version)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Created new file: %s\n", path)
 	return nil
 }
+
+func writeTemplateToFile(path string, t *template.Template, version string) (string, error) {
+	if _, err := os.Stat(path); !os.IsNotExist(err) {
+		return "", fmt.Errorf("failed to create file: %v already exists", path)
+	}
+
+	f, err := os.Create(path)
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+
+	err = t.Execute(f, version)
+	if err != nil {
+		return "", err
+	}
+
+	return f.Name(), nil
+}
+
+var sqlMigrationTemplate = template.Must(template.New("goose.sql-migration").Parse(`-- +goose Up
+-- SQL in this section is executed when the migration is applied.
+
+-- +goose Down
+-- SQL in this section is executed when the migration is rolled back.
+`))
+
+var goSQLMigrationTemplate = template.Must(template.New("goose.go-migration").Parse(`package migration
+
+import (
+	"database/sql"
+	"github.com/pressly/goose"
+)
+
+func init() {
+	goose.AddMigration(Up{{.}}, Down{{.}})
+}
+
+func Up{{.}}(tx *sql.Tx) error {
+	// This code is executed when the migration is applied.
+	return nil
+}
+
+func Down{{.}}(tx *sql.Tx) error {
+	// This code is executed when the migration is rolled back.
+	return nil
+}
+`))

migration.go

@@ -8,7 +8,6 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
-	"text/template"
 	"time"
 )
 
@@ -102,27 +101,6 @@ func NumericComponent(name string) (int64, error) {
 	return n, e
 }
 
-// CreateMigration creates a migration.
-func CreateMigration(name, migrationType, dir string, t time.Time) (path string, err error) {
-
-	if migrationType != "go" && migrationType != "sql" {
-		return "", errors.New("migration type must be 'go' or 'sql'")
-	}
-
-	timestamp := t.Format("20060102150405")
-	filename := fmt.Sprintf("%v_%v.%v", timestamp, name, migrationType)
-
-	fpath := filepath.Join(dir, filename)
-	tmpl := sqlMigrationTemplate
-	if migrationType == "go" {
-		tmpl = goSQLMigrationTemplate
-	}
-
-	path, err = writeTemplateToFile(fpath, tmpl, timestamp)
-
-	return
-}
-
 // FinalizeMigration updates the version table for the given migration,
 // and finalize the transaction.
 func FinalizeMigration(tx *sql.Tx, direction bool, v int64) error {
@@ -136,36 +114,3 @@ func FinalizeMigration(tx *sql.Tx, direction bool, v int64) error {
 
 	return tx.Commit()
 }
-
-var sqlMigrationTemplate = template.Must(template.New("goose.sql-migration").Parse(`
--- +goose Up
--- SQL in section 'Up' is executed when this migration is applied
-
-
--- +goose Down
--- SQL section 'Down' is executed when this migration is rolled back
-
-`))
-
-var goSQLMigrationTemplate = template.Must(template.New("goose.go-migration").Parse(`
-package migration
-
-import (
-	"database/sql"
-	"github.com/pressly/goose"
-)
-
-func init() {
-	goose.AddMigration(Up{{.}}, Down{{.}})
-}
-
-// Up{{.}} updates the database to the new requirements
-func Up{{.}}(tx *sql.Tx) error {
-	return nil
-}
-
-// Down{{.}} should send the database back to the state it was from before Up was ran
-func Down{{.}}(tx *sql.Tx) error {
-	return nil
-}
-`))

util.go

@@ -1,40 +0,0 @@
-package goose
-
-import (
-	"io"
-	"os"
-	"text/template"
-)
-
-// common routines
-
-func writeTemplateToFile(path string, t *template.Template, data interface{}) (string, error) {
-	f, e := os.Create(path)
-	if e != nil {
-		return "", e
-	}
-	defer f.Close()
-
-	e = t.Execute(f, data)
-	if e != nil {
-		return "", e
-	}
-
-	return f.Name(), nil
-}
-
-func copyFile(dst, src string) (int64, error) {
-	sf, err := os.Open(src)
-	if err != nil {
-		return 0, err
-	}
-	defer sf.Close()
-
-	df, err := os.Create(dst)
-	if err != nil {
-		return 0, err
-	}
-	defer df.Close()
-
-	return io.Copy(df, sf)
-}