Hello everyone,

I am using Firebird 2.1.3 Windows x86, and Firebird Provider for .NET 2.5.1.0.

I have had a strange error a couple of times in the last month, in two different computers.

For some reason, at a certain moment, and impossibly to reproduce, a query (that has been executed thousand times before and that will be executed later on without problems) suddenly provokes this error:

FirebirdSql.Data.FirebirdClient.FbException: Dynamic SQL Error
SQL error code = -104
a string constant is delimited by double quotes
at FirebirdSql.Data.FirebirdClient.FbCommand.ExecuteReader(CommandBehavior behavior)

The query is this:

SELECT PMH.PMH_A PMH_A,PMH.PMH_B PMH_B,PMH.PMH_C PMH_C,PMH.PMH_D PMH_D,PMH.PMH_E PMH_E,PMH.PMH_F PMH_F,PMH.PMH_G PMH_G,PMH.PMH_H PMH_H,PMH.PMH_I PMH_I,PMH.PMH_J PMH_J FROM "PMHTABLE" PMH WHERE (PMH.PMH_E=@string0 AND (PMH.PMH_C=@guid0 OR PMH.PMH_C IS NULL)) ORDER BY PMH.PMH_D ASC

The connection string uses dialect 3, character set UTF8 and packet size 8192 (the same as the database).

As I say, this query always runs without problems, except for this particular time that it failed.

I don't know what the problem can be - especially, because I cannot reproduce it. I use parameters, so there should be no problems with quotes... why is it saying "a string constant is delimited by double quotes"? And, if there is a problem, why doesn't it say it always?

Thanks in advance for any help.

Regards, Fernando