/// <summary>
/// Execute query and insert result into another collection. Support external collections
/// </summary>
internal BsonDataReader ExecuteQueryInto(string into, BsonAutoId autoId)
{
IEnumerable <BsonDocument> GetResultset()
{
using (var reader = this.ExecuteQuery(false))
{
while (reader.Read())
{
yield return(reader.Current.AsDocument);
}
}
}
var result = 0;
// if collection starts with $ it's system collection
if (into.StartsWith("$"))
{
SqlParser.ParseCollection(new Tokenizer(into), out var name, out var options);
var sys = _engine.GetSystemCollection(name);
result = sys.Output(GetResultset(), options);
}
// otherwise insert as normal collection
else
{
result = _engine.Insert(into, GetResultset(), autoId);
}
return(new BsonDataReader(result));
}
/// <summary>
/// Run query over collection using a query definition
/// </summary>
public IBsonDataReader Query(string collection, Query query)
{
if (string.IsNullOrWhiteSpace(collection))
{
throw new ArgumentNullException(nameof(collection));
}
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
IEnumerable <BsonDocument> source = null;
// test if is an system collection
if (collection.StartsWith("$"))
{
SqlParser.ParseCollection(new Tokenizer(collection), out var name, out var options);
// get registered system collection to get data source
var sys = this.GetSystemCollection(name);
source = sys.Input(this, options);
collection = sys.Name;
}
var exec = new QueryExecutor(this, _monitor, _sortDisk, _settings.UtcDate, collection, query, source);
return(exec.ExecuteQuery());
}
public override IEnumerable <BsonDocument> Input(LiteEngine engine, BsonValue options)
{
var query = options.AsString;
var sql = new SqlParser(engine, new Tokenizer(query), null);
using (var reader = sql.Execute())
{
while (reader.Read())
{
var value = reader.Current;
yield return(value.IsDocument ? value.AsDocument : new BsonDocument {
["expr"] = value
});
}
}
}
public override IEnumerable <BsonDocument> Input(BsonValue options)
{
var query = options?.AsString ?? throw new LiteException(0, $"Collection $query(sql) requires `sql` string parameter");
var sql = new SqlParser(_engine, new Tokenizer(query), null);
using (var reader = sql.Execute())
{
while (reader.Read())
{
var value = reader.Current;
yield return(value.IsDocument ? value.AsDocument : new BsonDocument {
["expr"] = value
});
}
}
}
