Initial commit

.gitignore

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+bindata.go

LICENSE

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+BSD 3-Clause License
+
+Copyright (c) 2016, Fuyu
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the copyright holder nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

README.md

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+# Go database migrate
+
+This is a simple database migration library for Go. This library is intended to be used with go-bindata.
+We recommended using a go generate command to update the go-bindata file.
+
+## Example
+
+`files/0001.sql`:
+
+```sql
+CREATE TABLE tests (
+	Name varchar(100) NOT NULL
+);
+
+INSERT INTO tests VALUES ('migration test');
+```
+
+Run `go-bindata --prefix files files`
+*Optionally add the flags `-nomemcopy` and `-nometadata`*
+
+`main.go`:
+
+```go
+package main
+
+import (
+	"migrate"
+)
+
+func main() {
+	db, err = sql.Open(`postgres`, `host=/run/postgresql dbname=testdb sslmode=disable`)
+	if err != nil {
+		fmt.Println(`Failed to connect to database. Message:`, err)
+	}
+	err = migrate.Migrate(db, 1, migrate.Options{Schema:`testschema`}, migrations.Asset}
+	if err != nil {
+		fmt.Println(`The migration failed! Message:`, err)
+	}
+
+	fmt.Println(`The database migration/update was successful`)
+}
+```
+
+## File names:
+
+The names of your migration files should look like this:
+
+```
+0001.sql
+0002.sql
+...
+0010.sql
+...
+0325.sql
+```

migrate.go

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+// Package migrate allows you to update your database from your application
+package migrate
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"strconv"
+)
+
+// Options contains all settings
+type Options struct {
+	TableName   string // Name used for version info table; defaults to DefaultTableName if not set
+	Schema      string // Schema used for version info table; For PostgreSQL, ignored if not set
+	AssetPrefix string
+}
+
+// DefaultTableName is the name used when no TableName is specified in Options
+const DefaultTableName = `version`
+
+// ErrUpdatesMissing indicates an update is missing, making it impossible to execute the migration
+var ErrUpdatesMissing = errors.New(`Missing migration files`)
+
+// ErrDatabaseNewer indicates that the database version is newer than the requested version. We throw an error because downgrades might cause dataloss
+var ErrDatabaseNewer = errors.New(`Current version is newer than the requested version`)
+
+const fileFormat = `%04d.sql`
+
+// AssetFunc is a function that returns the data for the given name
+type AssetFunc func(string) ([]byte, error)
+
+// Migrate executes
+func Migrate(db *sql.DB, version int, o Options, asset AssetFunc) error {
+	if o.TableName == `` {
+		o.TableName = DefaultTableName
+	}
+
+	table := o.TableName
+	if o.Schema != `` {
+		table = o.Schema + `.` + table
+	}
+
+	_, err := db.Exec(`CREATE TABLE IF NOT EXISTS ` + table + ` (Version integer NOT NULL PRIMARY KEY)`)
+	if err != nil {
+		return err
+	}
+
+	row := db.QueryRow(`SELECT Version FROM ` + table + ` ORDER BY Version DESC`)
+	if err != nil {
+		return err
+	}
+
+	var v int
+	err = row.Scan(&v)
+	if err != sql.ErrNoRows && err != nil {
+		return err
+	}
+
+	if v > version {
+		return ErrDatabaseNewer
+	}
+
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	for i := v + 1; i <= version; i++ {
+		asset, err := asset(fmt.Sprintf(o.AssetPrefix+fileFormat, version))
+		if err != nil {
+			return ErrUpdatesMissing
+		}
+
+		_, err = tx.Exec(string(asset))
+		if err != nil {
+			return err
+		}
+
+		_, err = tx.Exec(`INSERT INTO ` + table + ` VALUES (` + strconv.Itoa(i) + `)`)
+		if err != nil {
+			return err
+		}
+	}
+
+	err = tx.Commit()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}