ROWID columns
Informix®
When creating a table, Informix automatically adds a
ROWID integer column (applies to non-fragmented tables only).
The ROWID column is auto-filled with a unique number and can be used like a
primary key to access a given row.
Informix ROWID usage was a
common practice in the early days of Informix
4GL programming. Today it is recommended to define all your database tables with a
PRIMARY KEY to uniquely identify rows.
With Informix, the sqlca.sqlerrd[6]
register contains the ROWID of the last row affected by an INSERT,
UPDATE or DELETE statement.
Dameng®
Dameng support ROWID column, but the data type is different from Informix ROWIDs: Dameng rowids are
CHAR(18).
AAAA8mAALAAAAQkAAADameng rowids represent the physical addresses of the row, and cannot be used as permanent row
identifiers: After a DELETE, an INSERT statement might reuse the
physical place of the deleted row, to store the new row. However, rowids can be used in the context
of a transaction.
For example:
Solution
If your Genero BDL
application uses rowid columns, review the program logic to use primary keys insead. If the database
table does no define a primary key, it should be added. All references to
SQLCA.SQLERRD[6] must be removed, because this variable will not hold the
ROWID of the last modified row.
ROWID values must be
changed to CHAR(18).Informix INTEGER rowids fit in a
CHAR(18) variable. If you adapt the code to use CHAR(18) rowids,
the code will still work with Informix database.
When connected to a Dameng database, all references to sqlca.sqlerrd[6] must be
reviewed, because this register can not contain the rowid of the last affected row.
ROWID", the translation can be controlled
with the following FGLPROFILE
entry:dbi.database.dsname.ifxemul.rowid = { true | false }