Files
elwig/Elwig/Helpers/AppDbUpdater.cs

86 lines
3.6 KiB
C#

using Microsoft.Data.Sqlite;
using System;
namespace Elwig.Helpers {
public static class AppDbUpdater {
public static readonly int RequiredSchemaVersion = 2;
private static int _versionOffset = 0;
private static readonly Action<SqliteConnection>[] _updaters = new[] {
UpdateDbSchema_1_To_2, UpdateDbSchema_2_To_3
};
private static void ExecuteNonQuery(SqliteConnection cnx, string sql) {
using var cmd = cnx.CreateCommand();
cmd.CommandText = sql;
cmd.ExecuteNonQuery();
}
private static object? ExecuteScalar(SqliteConnection cnx, string sql) {
using var cmd = cnx.CreateCommand();
cmd.CommandText = sql;
return cmd.ExecuteScalar();
}
public static string CheckDb() {
using var cnx = AppDbContext.Connect();
var applId = (long?)ExecuteScalar(cnx, "PRAGMA application_id") ?? 0;
if (applId != 0x454C5747) throw new Exception("Invalid application_id of database");
var schemaVers = (long?)ExecuteScalar(cnx, "PRAGMA schema_version") ?? 0;
_versionOffset = (int)(schemaVers % 100);
if (_versionOffset != 0) {
// schema was modified manually/externally
// TODO issue warning
}
UpdateDbSchema(cnx, (int)(schemaVers / 100), RequiredSchemaVersion);
var userVers = (long?)ExecuteScalar(cnx, "PRAGMA user_version") ?? 0;
var major = userVers >> 24;
var minor = (userVers >> 16) & 0xFF;
var patch = userVers & 0xFFFF;
if (App.VersionMajor > major ||
(App.VersionMajor == major && App.VersionMinor > minor) ||
(App.VersionMajor == major && App.VersionMinor == minor && App.VersionPatch > patch))
{
long vers = (App.VersionMajor << 24) | (App.VersionMinor << 16) | App.VersionPatch;
ExecuteNonQuery(cnx, $"PRAGMA user_version = {vers}");
}
return $"{major}.{minor}.{patch}";
}
private static void UpdateDbSchema(SqliteConnection cnx, int fromVersion, int toVersion) {
if (fromVersion == toVersion) {
return;
} else if (fromVersion > toVersion) {
throw new Exception("schema_version of database is too new");
} else if (toVersion - 1 > _updaters.Length) {
throw new Exception("Unable to update database schema: Updater not implemented");
} else if (fromVersion <= 0) {
throw new Exception("schema_version of database is invalid");
}
ExecuteNonQuery(cnx, "PRAGMA locking_mode = EXCLUSIVE");
ExecuteNonQuery(cnx, "BEGIN EXCLUSIVE");
for (int i = fromVersion; i < toVersion; i++) {
_updaters[i - 1](cnx);
}
ExecuteNonQuery(cnx, "COMMIT");
ExecuteNonQuery(cnx, "VACUUM");
ExecuteNonQuery(cnx, $"PRAGMA schema_version = {toVersion * 100 + _versionOffset}");
}
private static void UpdateDbSchema_1_To_2(SqliteConnection cnx) {
ExecuteNonQuery(cnx, "DROP VIEW v_area_commitment");
ExecuteNonQuery(cnx, "ALTER TABLE delivery_part DROP COLUMN weighing_reason");
ExecuteNonQuery(cnx, "ALTER TABLE delivery_part ADD COLUMN weighing_reason TEXT CHECK(NOT (manual_weighing = FALSE AND weighing_reason IS NOT NULL))");
}
private static void UpdateDbSchema_2_To_3(SqliteConnection cnx) { }
}
}