add fitur migrations

Author: jiharal

README.md

@@ -1,5 +1,53 @@
 # Overview
  libpostgres is a collection of postgresql connections from various sources such as making connections with amp, elastic, etc.
 
+# How to use
+
+## Connect to database
+```go
+  dbOptions := libpostgres.Options{
+		Host:     "db_host",
+		Port:     "db_port",
+		Username: "db_username",
+		Password: "db_password",
+		DBName:   "db_name",
+		SSLMode:  "db_sslmode",
+	}
+	db, err := libpostgres.Connect(dbOptions)
+	if err != nil {
+		fmt.Println("Error conn to DB", err)
+		panic(err)
+	}
+```
+
+## Migrate database
+ - Create directory `db/migrations` on yout project.
+ - Create your file `sql` with format name 
+  - 000001_create_users_table.down.sql
+  - 000001_create_users_table.up.sql
+In the `.up.sql` file let's create the table:
+  ```sql
+  CREATE TABLE IF NOT EXISTS users(
+    user_id serial PRIMARY KEY,
+    username VARCHAR (50) UNIQUE NOT NULL,
+    password VARCHAR (50) NOT NULL,
+    email VARCHAR (300) UNIQUE NOT NULL
+  );
+  ```
+And in the .down.sql let's delete it:
+  ```sql
+  DROP TABLE IF EXISTS users;
+  ```
+
+Read more [here](https://github.com/golang-migrate/migrate/blob/master/database/postgres/TUTORIAL.md)
+
+ ```go
+	err := Migrate(db, "file://./migrations")
+	if err != nil {
+		fmt.Println("Error migrate DB", err)
+		panic(err)
+	}
+ ```
+
 # Constribute
  Please welcome .

go.mod

@@ -3,7 +3,8 @@ module github.com/jiharal/libpostgres
 go 1.14
 
 require (
-	github.com/lib/pq v1.0.0
+	github.com/golang-migrate/migrate/v4 v4.11.0
+	github.com/lib/pq v1.3.0
 	github.com/stretchr/testify v1.5.1
 	go.elastic.co/apm/module/apmsql v1.7.2
 )

go.sum

@@ -19,6 +19,8 @@ type Options struct {
 	Password       string
 	DBName         string
 	ConnectTimeout int
+	MaxOpenConn    int
+	MaxIdleConn    int
 	SSLCert        string
 	SSLKey         string
 	SSLRootCert    string
@@ -70,7 +72,8 @@ func Connect(options Options) (*sql.DB, error) {
 	if err != nil {
 		return nil, err
 	}
-
+	db.SetMaxOpenConns(options.MaxOpenConn)
+	db.SetMaxIdleConns(options.MaxIdleConn)
 	return db, nil
 }
 
@@ -107,6 +110,7 @@ func ConnectWithAMP(options Options) (*sql.DB, error) {
 	if err != nil {
 		return nil, err
 	}
-
+	db.SetMaxOpenConns(options.MaxOpenConn)
+	db.SetMaxIdleConns(options.MaxIdleConn)
 	return db, nil
 }

libpostgres.go

@@ -35,4 +35,7 @@ func TestLibpostgres(t *testing.T) {
 	require.NoError(t, err)
 	t.Log(name1)
 
+	errM := Migrate(db, "file://./migrations")
+	require.NoError(t, errM)
+
 }

libpostgres_test.go

@@ -0,0 +1,37 @@
+package libpostgres
+
+import (
+	"database/sql"
+
+	"github.com/golang-migrate/migrate/v4"
+	"github.com/golang-migrate/migrate/v4/database/postgres"
+	_ "github.com/golang-migrate/migrate/v4/source/file"
+)
+
+// Migrate is used to migrate table
+// Ex: Migrate(opt, "file://db/migrations")
+func Migrate(db *sql.DB, path string) error {
+	driver, err := postgres.WithInstance(db, &postgres.Config{})
+	if err != nil {
+		return err
+	}
+	m, err := migrate.NewWithDatabaseInstance(path, "postgres", driver)
+	err = m.Up()
+	if err != nil && err.Error() != "no change" {
+		return err
+	}
+	return nil
+}
+
+func DownOneStep(db *sql.DB, path string) error {
+	driver, err := postgres.WithInstance(db, &postgres.Config{})
+	if err != nil {
+		return err
+	}
+	m, err := migrate.NewWithDatabaseInstance(path, "postgres", driver)
+	err = m.Steps(-1)
+	if err != nil {
+		return err
+	}
+	return nil
+}

migration.go

@@ -0,0 +1 @@
+DROP TABLE IF EXISTS kurir;

migrations/1_create_kurir_table.down.sql

@@ -0,0 +1,6 @@
+CREATE TABLE IF NOT EXISTS kurir(
+   user_id serial PRIMARY KEY,
+   username VARCHAR (50) UNIQUE NOT NULL,
+   password VARCHAR (50) NOT NULL,
+   email VARCHAR (300) UNIQUE NOT NULL
+);

migrations/1_create_kurir_table.up.sql

@@ -0,0 +1 @@
+alter table kurir drop column if exists address;

migrations/2_add_colum_address.down.sql

@@ -0,0 +1 @@
+alter table kurir add column if exists address varying(255);