/// <summary>
/// delete tables of old versions and recreate it
/// </summary>
public void VerDbVersions()
{
//to do - a version table for VERSIONDB too? for the insert of new tables
_ = RunSqliteCommand("create table if not exists VERSIONDB (Key integer, USER integer,BOOK integer);");
//
DbVersions dbVersions;
using (SqliteDataReader Retorno = Task.Run(async() => await RunSqliteCommand("select USER,BOOK from VERSIONDB")).Result)
{
_ = Retorno.Read();
if (Retorno.HasRows)
{
dbVersions = new DbVersions()
{
USER = Retorno.GetWithNullableInt(0),
BOOK = Retorno.GetWithNullableInt(1)
};
}
else
{
dbVersions = new DbVersions()
{
USER = 0,
BOOK = 0
};
AddorUpdateVersionDb(false, dbVersions);
}
}
bool updateVersionDb = false;
if ((dbVersions.BOOK < ActualDbVersions.BOOK) || (dbVersions.USER < ActualDbVersions.USER))
{
_ = RunSqliteCommand("drop table if exists USER");
updateVersionDb = true;
}
if (dbVersions.BOOK < ActualDbVersions.BOOK)
{
_ = RunSqliteCommand("drop table if exists BOOK");
_ = RunSqliteCommand("drop table if exists BOOKRATING");
updateVersionDb = true;
}
if (updateVersionDb)
{
AddorUpdateVersionDb(true, ActualDbVersions);
}
}
private void AddorUpdateVersionDb(bool isUpdate, DbVersions dbVersions)
{
string command;
if (!isUpdate)
{
command = "insert into Versiondb(key,USER,BOOK) values ('1',@USER,@BOOK)";
}
else
{
command = "update Versiondb set USER = @USER,BOOK = @BOOK where key = '1'";
}
List <SqliteParameter> parameters = new List <SqliteParameter>()
{
new SqliteParameter("@USER", dbVersions.USER),
new SqliteParameter("@BOOK", dbVersions.BOOK)
};
_ = RunSqliteCommand(command, parameters);
}
