... So I run it in different dll's, I use dockers share function to map all instances to the same drive where the db is. My GraphQL image was started without a ~ before it, so it mapped to a different drive, with an old db copy.
Problem between chair and monitor confirmed.
Problem between chair and monitor confirmed.
Hi - I am looking to use this to write a bunch of data (quickly) to an in-memory store but after that, I'd like to save it to disk. I am writing millions of records in seconds, so the in memory option is faster during all of that churn, but I'd like to then move it to disk without writing all the records again. Is this possible? I did something similar with Lucene.Net and it worked very well.
@lbnascimento - 'StackOverflow' was a hyperlink, but here's the url as text: https://stackoverflow.com/questions/57139624/how-to-check-if-litedb-database-file-has-password-or-not-in-c
If the first byte is 0, then the file is not encrypted
If it is 1, it is encrypted
We may use values other than 1 in future versions for different encryption modes, so it is preferable to test for 0 than for 1
@lbnascimento Thanks - i tested the answer and received 0 as the first byte for an unencrypted files but for encrypted files i got two different values - 73 & 176. Here's the code i was using
IsDbPasswordProtected(string path)
{
using (FileStream fs = File.OpenRead(path))
{
byte[] byteArray = new byte[1];
int numBytesToRead = byteArray.Length;
while (fs.Read(byteArray, 0, byteArray.Length) > 0)
{
}
return byteArray.Single() != 0;
}
}bool IsDbPasswordProtected(string path)
{
using (FileStream fs = File.OpenRead(path))
{
return fs.ReadByte() > 0;
}
}
@lbnascimento Thanks a lot - i added your answer as a comment on Github. Incidentally the questions were related to the work on this pull-request: https://github.com/julianpaulozzi/LiteDbExplorer/pull/50/.
I have a question about using Upsert().
So let's say I have this method:
using (var db = new LiteDatabase(App.DatabasePath))
{
var col = db.GetCollection<EntryInfo>("entry_coll");
var entry = new EntryInfo()
{
EntryId = 99,
Title = "SampleTitle",
Original = "FirstString"
};
col.Upsert(entry)
}Which adds the entry into the database, but then later on, I call this section of code:
using (var db = new LiteDatabase(App.DatabasePath))
{
var col = db.GetCollection<EntryInfo>("entry_coll");
var entry = new EntryInfo()
{
EntryId = 99,
Title = "SampleTitle",
Original = "UPDATEDString"
};
col.Upsert(entry)
}Which adds another row, instead of updating the existing row. How do I tell it to update what's changed between the 2 entries?
using (var db = new LiteDatabase(App.DatabasePath))
{
var dbTags = db.GetCollection<VnTagData>("vntagdump");
List<Tag> tagDump = (await VndbUtils.GetTagsDumpAsync()).ToList();
List<VnTagData> tagsToAdd = new List<VnTagData>();
foreach (var item in tagDump)
{
var data = dbTags.Query().ToList(); //suceeds here on first add to db, crashes anytime after the first run
var prevEntry = data.FirstOrDefault(x => x.TagId == item.Id) ?? new VnTagData();
var entry = prevEntry ?? new VnTagData();
entry.TagId = item.Id; //uint
entry.Name = item.Name; //string
entry.Description = item.Description; //string
entry.Category = item.TagCategory; //enum {Content, Technical, Other}
entry.Parents = item.Parents; //ReadOnlyCollection<uint>
tagsToAdd.Add(entry);
}
dbTags.Upsert(tagsToAdd);
Debug.WriteLine("Done");
}
on the line "var data = dbTags.Query().ToList()", it crashes the second time I run it
the first time I execute it, there is no database or collection/table
after I execute it once, there are 2560 elements in the table/collection
and I get the following error:
LiteDB.LiteException: Failed to create instance for type 'System.Collections.ObjectModel.ReadOnlyCollection.....
System.ArgumentException: Type 'System.Collections.ObjectModel.ReadOnlyCollection`1[System.UInt32]' does not have a default constructor (Parameter 'type')
LiteDB.LiteException: Failed to create instance for type 'System.Collections.ObjectModel.ReadOnlyCollection.....
System.ArgumentException: Type 'System.Collections.ObjectModel.ReadOnlyCollection`1[System.UInt32]' does not have a default constructor (Parameter 'type')
@micah686 If you really need to use
ReadOnlyCollection, you must create a custom constructor for your data classes and use the BsonCtor attribute to tell LiteDB to use it
@micah686 Something like this:
[BsonCtor]
public Tag(UInt32 _id, String name, String description, ..., BsonArray aliases, BsonArray parents)
{
Id = _id;
Name = name;
Description = description;
...
Aliases = aliases.Select(x => x.AsString).ToList().AsReadOnly();
Parents = parents.Select(x => (UInt32)x.AsInt64).ToList().AsReadOnly();
}
Hello LiteDb Friends! I'm running into a performance challenge dealing with long-running queries. Is there a way to cancel a query? We are loading a list as a user sets filter criteria and I would like to cancel the previous operation when the filter is updated.
I'm on LiteDb 5.0.8. As a note, LiteDb 5 w/ partial deserialization has allowed us to increase performance by a substantial amount and we're really enjoying using it.
@jjallen37 You can get an
IBsonDataReader either by calling LiteDatabase.Execute(string sql) or by calling LiteCollection.Query().ExecuteReader()
I think that is probably what I'm looking for, thanks! I would be using it in the latter case
LiteCollection.Query(). In my case, we go all the way through like this: Query().Where().OrderBy().Select().Limit().Offset() then finally to ToList(). Would there be any functional difference between the reader returned from Query() and Offset()?
@jjallen37 The only caveat to this solution is that you'll have to call
ExecuteReader() after these calls, and now you're dealing with an IBsonDataReader
And you'll have to iterate through it manually, similarly to how you would iterate manually through an
IEnumerable
Something like:
Essentially this, right? https://github.com/mbdavid/LiteDB/blob/master/LiteDB/Client/Database/LiteQueryable.cs#L244
I was about to submit a GitHub issue about something, but I feel I should go ahead and check while I'm here. I want to clear all my Indexes for a collection, but I can't find out which indexes I already have set. Is there any functionality to return indexes or to drop all existing ones?
@ColonelBundy So, if you are working with an untyped collection, you need to do everything manually, including setting the reference subdocument correctly
Where the
$ref attribute stores the name of the collection to which it refers and $id stores the id of the referenced document