Nulls information in system tables

Does anyone know where I can find if a column can contain nulls in the system tables. I've searched in syscolumns, sysconstraints, sysdefaults etc and I can't find this info. dbschema, dbaccess all know about columns that are "not null" so this info must be stored somewhere .. TIA

Arturo Koosau wrote: > Does anyone know where I can find if a column can contain nulls in the > system tables. > I've searched in syscolumns, sysconstraints, sysdefaults etc and I can't > find this info. > dbschema, dbaccess all know about columns that are "not null" so this > info must be stored somewhere .. The information is encoded into the type column of the syscolumns table record for the column. In pseudocode the test is: if ((syscolumns.coltype & 0x0100) == 0) ColumnCanBeNull = TRUE ColumnIsNotNull = FALSE else ColumnIsNotNull = TRUE ColumnCanBeNull = FALSE endif In ESQL/C you can use the define SQLNONULL contained in $INFORMIXDIR/incl/esql/sqltypes.h To extract the actual datatype use: SqlDataType = syscolumns.coltype & SQLTYPE; /* SQLTYPE is defined as 0xFF */ Art S. Kagel

create table tessie ( a int , b int not null); select a.* from syscolumns a , systables b where a.tabid = b.tabid and b.tabname ='tessie' colname a tabid 114 colno 1 coltype 2 <<<<<<<<<<<<---------------------- collength 4 colmin colmax extended_id 0 colname b tabid 114 colno 2 coltype 258 <<<<<<<<<<<<<<<<<------------------ 256 + 2....... collength 4 colmin colmax extended_id 0 See you Superboer. Arturo Koosau schreef: > Does anyone know where I can find if a column can contain nulls in the > system tables. > I've searched in syscolumns, sysconstraints, sysdefaults etc and I can't > find this info. > dbschema, dbaccess all know about columns that are "not null" so this info > must be stored somewhere .. > TIA > > ------=_Part_172820_19001579.1153768104017 > Content-Type: text/html; charset=ISO-8859-1 > X-Google-AttachSize: 343 > > <div>Does anyone know where I can find if a column can contain nulls in the system tables.</div> > <div>I've searched in syscolumns, sysconstraints, sysdefaults etc and I can't find this info.</div> > <div>dbschema, dbaccess all know about columns that are&nbsp; &quot;not null&quot; so this info must be stored somewhere ..</div> > <div>TIA</div> > > ------=_Part_172820_19001579.1153768104017--