PostgresSQL. Delete with Take (linq2db v3.1.0)

Using Delete/DeleteAsync methods with Take generates sql which doesnt work.

Exception message:

Stack trace:

18:38:34|Error|ServersWorker|42601: ошибка синтаксиса (примерное положение: "LIMIT") Npgsql.PostgresException (0x80004005): 42601: ошибка синтаксиса (примерное положение: "LIMIT")
at Npgsql.NpgsqlConnector.<>c__DisplayClass160_0.<<DoReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at Npgsql.NpgsqlConnector.<>c__DisplayClass160_0.<<DoReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at Npgsql.NpgsqlDataReader.NextResult(Boolean async, Boolean isConsuming)
at Npgsql.NpgsqlCommand.ExecuteReaderAsync(CommandBehavior behavior, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlCommand.ExecuteNonQuery(Boolean async, CancellationToken cancellationToken)
at LinqToDB.Data.DataConnection.ExecuteNonQueryAsync(CancellationToken cancellationToken)
at LinqToDB.Data.DataConnection.QueryRunner.ExecuteNonQueryAsync(CancellationToken cancellationToken)
at LinqToDB.Linq.QueryRunner.NonQueryQueryAsync(Query query, IDataContext dataContext, Expression expression, Object[] ps, Object[] preambles, CancellationToken cancellationToken)
at LinqToDB.Linq.ExpressionQuery`1.LinqToDB.Async.IQueryProviderAsync.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)
at LinqToDB.LinqExtensions.DeleteAsync[T](IQueryable`1 source, CancellationToken token)
at Services.Services.Servers.ServerDeletion.DeleteMt5Deals(Int32 serverId) in C:\Services\Servers\ServerDeletion.cs:line 97
at Services.Services.Servers.ServerDeletion.DeleteMt5(Server mt5Server) in C:\Services\Servers\ServerDeletion.cs:line 36
at Services.Services.Servers.ServerDeletion.DeleteServer(Server server) in C:\Services\Servers\ServerDeletion.cs:line 29
at Core.Workers.ServersWorker.ExecuteAsync(CancellationToken stoppingToken) in C:\Services\Servers\ServerDeletion.cs:line 41
Exception data:
Severity: ОШИБКА
SqlState: 42601
MessageText: ошибка синтаксиса (примерное положение: "LIMIT")
Position: 63
File: scan.l
Line: 1149
Routine: scanner_yyerror

Steps to reproduce

This query causes error above:

deleted = await _context.Deals
                    .Where(w => w.ServerId == serverId)
                    .Take(_chunkSize)
                    .DeleteAsync();

Generated SQL:

DECLARE @serverId Integer -- Int32
SET @serverId = 1
DECLARE @take Integer -- Int32
SET @take = 10000

DELETE FROM
"public".deals w
WHERE
w.server_id = :serverId
LIMIT :take

Without Take() it works fine.

Environment details

linq2db installed packages:

<PackageReference Include="linq2db" Version="3.1.0" />
<PackageReference Include="linq2db.AspNet" Version="3.1.0" />
<PackageReference Include="linq2db.t4models" Version="3.1.0" />

Database Provider: PostgreSQL 12 Operating system: Win10 .NET Framework: netcoreapp3.1

[MaceWindu]

you should be able to delete it using filter by top 10 ids (if you have unique single-column id in this table)

_context.Deals
                    .Where(_ => _context.Deals
                                          .Take(_chunkSize)
                                          .Select(w => w.Id).Contains(_.Id))
                    .DeleteAsync();

[szguoxz]

After two years, still not fixed? I thought it’s an easy fix. YEs, I can write delete(x=>idquery.take(100).contains(x.id)), but it’s much more elegant to write query.take(100).delete(). besides it worked on SQL server. 😃 Any plan to update the postgresql driver? I found a lot linqtodb syntax does not work on postgresql. Upinsert won’t work either. Seems postgresql for linqtodb is not quite ready?

Calvin