Every other query fails with syntax error - npgsql

Question

I use CockroachDb and Npgsql driver.
I have a simple Users table. When I insert new record, every other query fails with syntax error, which seems bizarre to me.
CREATE TABLE Users (
RequestIdentifier BYTEA NOT NULL UNIQUE,
Identifier UUID PRIMARY KEY DEFAULT gen_random_uuid(),
Id INT8 NOT NULL DEFAULT unique_rowid(),
Email BYTEA NOT NULL UNIQUE,
Username BYTEA NOT NULL,
PasswordHash BYTEA NOT NULL
);
var q = #"
INSERT INTO Users (RequestIdentifier, Email, Username, PasswordHash)
VALUES (#RequestIdentifier, #Email, #Username, #PasswordHash)
ON CONFLICT (RequestIdentifier)
DO NOTHING
RETURNING Identifier
";
byte[] userIdentifier = null;
using (var cmd = new NpgsqlCommand(q, dbConn)) {
cmd.Parameters.Add("RequestIdentifier", NpgsqlDbType.Bytea);
cmd.Parameters.Add("Email", NpgsqlDbType.Bytea);
cmd.Parameters.Add("Username", NpgsqlDbType.Bytea);
cmd.Parameters.Add("PasswordHash", NpgsqlDbType.Bytea);
await cmd.PrepareAsync();
cmd.Parameters[0].Value = msg.RequestIdentifier;
cmd.Parameters[1].Value = msg.Email;
cmd.Parameters[2].Value = msg.Username;
cmd.Parameters[3].Value = passwordHash;
try {
userIdentifier = ((Guid) await cmd.ExecuteScalarAsync()).ToByteArray();
} catch (PostgresException e) when (e.SqlState == SqlErrorCodes.UniqueViolation) {
logger.Information("Email {Email} already in use", UTF8.GetString(msg.Email));
} catch (PostgresException e) {
logger.Error("{Exception}", e);
throw;
}
}
Npgsql.PostgresException (0x80004005): 42601: at or near "close": syntax error
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.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.ExecuteScalar(Boolean async, CancellationToken cancellationToken)
at OwlAuthentication.Services.CockroachDbStorageService.CreateOrRetrieveExistingUser(SignUpMessage msg) in C:\Users\Che Khen Kho\Desktop\dotnet\OwlAuthentication\Services\CockroachDbStorageService.cs:line 94
Exception data:
Severity: ERROR
SqlState: 42601
MessageText: at or near "close": syntax error
Detail: source SQL:
CLOSE ALL
^
File: lexer.go
Line: 175
Routine: Error
If I try, say, 10 queries, 5 of them would fail with this exception, but quite often more than 5 rows would actually get inserted (sometimes 6, sometimes 8, etc.).
I tested it with PostgreSQL as well (using uuid_generate_v4 instead of gen_random_uuid and BIGSERIAL for Id column), and everything works fine.

Answer 1

I think this is covered by this issue (https://github.com/cockroachdb/cockroach/issues/45490) which is fixed in CockroachDB v20.1