dbmate/driver/postgres/postgres.go
2015-11-25 10:57:58 -08:00

103 lines
2.6 KiB
Go

package postgres
import (
"database/sql"
"fmt"
"github.com/adrianmacneil/dbmate/driver/shared"
pq "github.com/lib/pq"
"net/url"
)
// Driver provides top level database functions
type Driver struct {
}
// Open creates a new database connection
func (postgres Driver) Open(u *url.URL) (*sql.DB, error) {
return sql.Open("postgres", u.String())
}
// postgresExec runs a sql statement on the "postgres" database
func (postgres Driver) postgresExec(u *url.URL, statement string) error {
// connect to postgres database
postgresURL := *u
postgresURL.Path = "postgres"
db, err := postgres.Open(&postgresURL)
if err != nil {
return err
}
defer db.Close()
// run statement
_, err = db.Exec(statement)
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)
return postgres.postgresExec(u, fmt.Sprintf("DROP DATABASE IF EXISTS %s",
pq.QuoteIdentifier(database)))
}
// HasMigrationsTable returns true if the schema_migrations table exists
func (postgres Driver) HasMigrationsTable(db *sql.DB) (bool, error) {
return false, fmt.Errorf("not implemented")
}
// CreateMigrationsTable creates the schema_migrations table
func (postgres Driver) CreateMigrationsTable(db *sql.DB) error {
_, err := db.Exec(`CREATE TABLE IF NOT EXISTS schema_migrations (
version varchar(255) PRIMARY KEY)`)
return err
}
// SelectMigrations returns a list of applied migrations
func (postgres Driver) SelectMigrations(db *sql.DB) (map[string]struct{}, error) {
rows, err := db.Query("SELECT version FROM schema_migrations")
if err != nil {
return nil, err
}
defer rows.Close()
migrations := map[string]struct{}{}
for rows.Next() {
var version string
if err := rows.Scan(&version); err != nil {
return nil, err
}
migrations[version] = struct{}{}
}
return migrations, nil
}
// InsertMigration adds a new migration record
func (postgres Driver) InsertMigration(db shared.Transaction, version string) error {
_, err := db.Exec("INSERT INTO schema_migrations (version) VALUES ($1)", version)
return err
}
// DeleteMigration removes a migration record
func (postgres Driver) DeleteMigration(db shared.Transaction, version string) error {
_, err := db.Exec("DELETE FROM schema_migrations WHERE version = $1", version)
return err
}