How to select a entry in Database using multiple conditions? - entity-framework

Question

I'm working on a project for fun, and I am saving the users current GuildId, UserId, their level, and current Exp. It works partially, but it seems to just grab the first result of only one condition.
I've tried a number of different ways of selecting an item from the database but as this is a hobby I feel I'm missing something very obvious. Ive logged my ways of fetching UserId and GuildId and they return the correct values.
It currently adds a new entry if one doesn't exist, and will update the Xp correctly but only for one entry. It seems to ignore the GuildId and just find the first entry matching UserId and save it there.
public static async Task SaveExp(ulong guildId, ulong userId, int level, uint xp, DateTime cooldown)
{
using (var dbContext = new DatabaseHandler())
{
if (dbContext.Exps.Any(x => x.GuildId == guildId && x.UserId == userId))
{
var current = dbContext.Exps.FirstOrDefault(x => x.GuildId == guildId && x.UserId == userId);
if (current != null)
{
current.Xp += xp;
current.Level += level;
dbContext.Exps.Update(current);
}
}
else
{
dbContext.Exps.Add(new Exp
{
GuildId = guildId,
UserId = userId,
Level = level,
Xp = xp,
Cooldown = cooldown
});
}
await dbContext.SaveChangesAsync();
}
}
I want it to save the Xp to the entry where both GuildId and UserId criteria are met.

Answer 1

You could refactor your code slightly like this to make it more efficient. Your code does do what you are describing though. If you should only ever have a single/null result returned then you should use SingleOrDefault/SingleOrDefaultAsync which ensures that, more results would result in an InvalidOperationException.
public static async Task SaveExp(ulong guildId, ulong userId, int level, uint xp, DateTime cooldown)
{
using (var dbContext = new DatabaseHandler())
{
var current = await dbContext.Exps.FirstOrDefaultAsync(x => x.GuildId == guildId && x.UserId == userId);
if (current != null)
{
current.Xp += xp;
current.Level += level;
// you should not need this next line in EF6
// the entity is already attached as you just retrieved it and should be tracked
dbContext.Exps.Update(current);
}
else
{
dbContext.Exps.Add(new Exp
{
GuildId = guildId,
UserId = userId,
Level = level,
Xp = xp,
Cooldown = cooldown
});
}
await dbContext.SaveChangesAsync();
}
}