85 lines
2.5 KiB
Go

// Package msmigrate implements sqlmigrate.Migrator for Microsoft SQL Server
// using database/sql with github.com/microsoft/go-mssqldb.
//
// db, err := sql.Open("sqlserver", "sqlserver://user:pass@host:1433?database=mydb")
package msmigrate
import (
"context"
"database/sql"
"errors"
"fmt"
mssql "github.com/microsoft/go-mssqldb"
"github.com/therootcompany/golib/database/sqlmigrate"
)
// Migrator implements sqlmigrate.Migrator using a *sql.DB with SQL Server.
type Migrator struct {
DB *sql.DB
}
// New creates a Migrator from the given database handle.
func New(db *sql.DB) *Migrator {
return &Migrator{DB: db}
}
var _ sqlmigrate.Migrator = (*Migrator)(nil)
// ExecUp runs the up migration SQL inside a transaction.
func (m *Migrator) ExecUp(ctx context.Context, mig sqlmigrate.Migration) error {
return m.execInTx(ctx, mig.Up)
}
// ExecDown runs the down migration SQL inside a transaction.
func (m *Migrator) ExecDown(ctx context.Context, mig sqlmigrate.Migration) error {
return m.execInTx(ctx, mig.Down)
}
func (m *Migrator) execInTx(ctx context.Context, sqlStr string) error {
tx, err := m.DB.BeginTx(ctx, nil)
if err != nil {
return fmt.Errorf("%w: begin: %w", sqlmigrate.ErrExecFailed, err)
}
defer func() { _ = tx.Rollback() }()
if _, err := tx.ExecContext(ctx, sqlStr); err != nil {
return fmt.Errorf("%w: exec: %w", sqlmigrate.ErrExecFailed, err)
}
if err := tx.Commit(); err != nil {
return fmt.Errorf("%w: commit: %w", sqlmigrate.ErrExecFailed, err)
}
return nil
}
// Applied returns all applied migrations from the _migrations table.
// Returns an empty slice if the table does not exist (SQL Server error 208).
func (m *Migrator) Applied(ctx context.Context) ([]sqlmigrate.AppliedMigration, error) {
rows, err := m.DB.QueryContext(ctx, "SELECT id, name FROM _migrations ORDER BY name")
if err != nil {
// SQL Server error 208: "Invalid object name '_migrations'"
if msErr, ok := errors.AsType[mssql.Error](err); ok && msErr.Number == 208 {
return nil, nil
}
return nil, fmt.Errorf("%w: %w", sqlmigrate.ErrQueryApplied, err)
}
defer rows.Close()
var applied []sqlmigrate.AppliedMigration
for rows.Next() {
var a sqlmigrate.AppliedMigration
if err := rows.Scan(&a.ID, &a.Name); err != nil {
return nil, fmt.Errorf("%w: scanning row: %w", sqlmigrate.ErrQueryApplied, err)
}
applied = append(applied, a)
}
if err := rows.Err(); err != nil {
return nil, fmt.Errorf("%w: reading rows: %w", sqlmigrate.ErrQueryApplied, err)
}
return applied, nil
}