public IEnumerable <Migration> BuildMigrations(int version)
{
Console.WriteLine($"Running migrations from version {version}.");
foreach (var migration in migrationFactory.BuildMigrations(version))
{
Console.WriteLine(migration.Sql);
yield return(migration);
}
}
public async Task MigrateAsync(IMigrationFactory migrationFactory, CancellationToken cancellationToken)
{
if (migrationFactory == null)
{
throw new ArgumentNullException(nameof(migrationFactory));
}
cancellationToken.ThrowIfCancellationRequested();
using (var connection = await connectionFactory(cancellationToken))
using (var transaction = connection.BeginTransaction(IsolationLevel.Serializable))
{
var version = await connection.QuerySingleAsync <int>(
"PRAGMA user_version;",
transaction : transaction
).ConfigureAwait(false);
var migrations = migrationFactory.BuildMigrations(version);
foreach (var migration in migrations)
{
cancellationToken.ThrowIfCancellationRequested();
await connection.ExecuteAsync(
sql : migration.Sql,
param : migration.Parameter,
commandType : migration.CommandType,
commandTimeout : migration.CommandTimeout,
transaction : transaction
).ConfigureAwait(false);
// Bump version; Dapper does not support parameters with PRAGMAs.
// SQL injection is not an issue here, since we use integers for version.
await connection.ExecuteAsync(
$"PRAGMA user_version = {++version};",
transaction : transaction
).ConfigureAwait(false);
}
cancellationToken.ThrowIfCancellationRequested();
transaction.Commit();
}
}