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Support non-PostgreSQL databases

master v1.3.0
Nise Void 2 years ago
parent
commit
f39c1c640a
Signed by: NiseVoid GPG Key ID: FBA14AC83EA602F3
  1. 36
      migrate.go
  2. 35
      query.go
  3. 29
      util.go

36
migrate.go

@ -11,7 +11,7 @@ import (
// 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
Schema string // Schema used for version info table; In PostgreSQL the current schema is changed to the one specified here
AssetPrefix string
}
@ -29,36 +29,42 @@ type AssetFunc func(string) ([]byte, error)
// Migrate executes migrations to get to the desired version
// Downgrading is not supported as it could result in data loss
func Migrate(db *sql.DB, version int, o Options, asset AssetFunc) error {
dbType := getDbType(db)
if o.TableName == `` {
o.TableName = DefaultTableName
}
var err error
searchPath := `public`
_ = db.QueryRow(`SHOW search_path`).Scan(&searchPath)
if o.Schema != `` {
_, _ = db.Exec(`CREATE SCHEMA IF NOT EXISTS ` + o.Schema)
tx, err := db.Begin()
if err != nil {
return err
}
defer tx.Rollback()
_, err = db.Exec(`SET search_path TO ` + o.Schema)
if o.Schema != `` {
err = createSchemaIfNotExists(tx, o.Schema)
if err != nil {
return err
}
}
tx, err := db.Begin()
if err != nil {
return err
if dbType == `pq` {
_ = tx.QueryRow(`SHOW search_path`).Scan(&searchPath)
_, err = tx.Exec(`SET search_path TO ` + o.Schema)
if err != nil {
return err
}
}
}
defer tx.Rollback()
_, err = tx.Exec(`CREATE TABLE IF NOT EXISTS ` + o.TableName + ` (Version integer NOT NULL PRIMARY KEY)`)
versionTable, err := createTableIfNotExists(tx, o.Schema, o.TableName)
if err != nil {
return err
}
row := tx.QueryRow(`SELECT Version FROM ` + o.TableName + ` ORDER BY Version DESC`)
row := tx.QueryRow(`SELECT version FROM ` + versionTable + ` ORDER BY Version DESC`)
var v int
err = row.Scan(&v)
@ -80,13 +86,13 @@ func Migrate(db *sql.DB, version int, o Options, asset AssetFunc) error {
return errorf(err)
}
_, err = tx.Exec(`INSERT INTO ` + o.TableName + ` VALUES (` + strconv.Itoa(i) + `)`)
_, err = tx.Exec(`INSERT INTO ` + versionTable + ` (version) VALUES (` + strconv.Itoa(i) + `)`)
if err != nil {
return errorf(err)
}
}
if o.Schema != `` {
if dbType == `pq` && o.Schema != `` {
_, err = tx.Exec(`SET search_path TO ` + searchPath)
if err != nil {
return err

35
query.go

@ -0,0 +1,35 @@
package migrate
import "database/sql"
func createSchemaIfNotExists(tx *sql.Tx, schema string) error {
row := tx.QueryRow(`SELECT 1 FROM information_schema.schemata WHERE schema_name = '` + schema + `'`)
err := row.Scan(new(int))
if err == sql.ErrNoRows {
_, err = tx.Exec(`CREATE SCHEMA ` + schema)
if err != nil {
return err
}
}
return err
}
func createTableIfNotExists(tx *sql.Tx, schema, table string) (string, error) {
versionTable := table
var schemaCond string
if schema != `` {
versionTable = schema + `.` + table
schemaCond = ` AND table_schema = '` + schema + `'`
}
row := tx.QueryRow(`SELECT 1 FROM information_schema.tables WHERE table_name = '` + table + `'` + schemaCond)
err := row.Scan(new(int))
if err == sql.ErrNoRows {
_, err = tx.Exec(`CREATE TABLE ` + versionTable + ` (version integer NOT NULL PRIMARY KEY)`)
if err != nil {
return ``, err
}
}
return versionTable, err
}

29
util.go

@ -0,0 +1,29 @@
package migrate
import (
"database/sql"
"reflect"
"strings"
)
func getPkgName(db *sql.DB) string {
t := reflect.TypeOf(db.Driver())
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
path := t.PkgPath()
parts := strings.Split(path, `/vendor/`)
return parts[len(parts)-1]
}
func getDbType(db *sql.DB) string {
switch getPkgName(db) {
case `github.com/lib/pq`, `github.com/jackc/pgx/stdlib`:
return `pq`
case `github.com/go-sql-driver/mysql`, `github.com/ziutek/mymysql/godrv`:
return `my`
case `github.com/denisenkom/go-mssqldb`:
return `ms`
}
return ``
}
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