Initial commit

driver/postgres/postgres.go

@@ -0,0 +1,103 @@
+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
+}