On 30.08.2013 15:42, silvioprog wrote:
2013/8/29 Michael Van Canneyt <mich...@freepascal.org <mailto:mich...@freepascal.org>>On Thu, 29 Aug 2013, silvioprog wrote: Other interesting feature is the property EmptyAsNull: http://docwiki.embarcadero.__com/VCL/XE/en/IBCustomDataSet.__TIBStringField.EmptyAsNull <http://docwiki.embarcadero.com/VCL/XE/en/IBCustomDataSet.TIBStringField.EmptyAsNull> It tests if field (ftString) is empty (f = ''), if yes, it set the field value to null (f.Clear). Apparently a IBX specific extension. I don't see the value of this. empty and null are different things. Michael. Some Delphi components (Zeos, JvDBEdit) have this option. Assuming this table: test id integer, name varchar(10) not null unique You can: id|name 1| <null> 2| <null> But: 1| <empty> 2| <empty> << error, unique key
And again here is an exception of the rule: in SQL Server you can't have multiple NULL values in a unique key column *sigh*
Regards, Sven _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
