| The PostgreSQL 9.0 Reference Manual - Volume 2 - Programming Guide
by The PostgreSQL Global Development Group Paperback (6"x9"), 478 pages ISBN 9781906966065 RRP £14.95 ($19.95) Sales of this book support the PostgreSQL project! Get a printed copy>>> |
9.3.5 Record Types
name RECORD;
Record variables are similar to row-type variables, but they have no
predefined structure. They take on the actual row structure of the
row they are assigned during a SELECT or FOR command. The substructure
of a record variable can change each time it is assigned to.
A consequence of this is that until a record variable is first assigned
to, it has no substructure, and any attempt to access a
field in it will draw a run-time error.
Note that RECORD is not a true data type, only a placeholder.
One should also realize that when a PL/pgSQL
function is declared to return type record, this is not quite the
same concept as a record variable, even though such a function might
use a record variable to hold its result. In both cases the actual row
structure is unknown when the function is written, but for a function
returning record the actual structure is determined when the
calling query is parsed, whereas a record variable can change its row
structure on-the-fly.
| ISBN 9781906966065 | The PostgreSQL 9.0 Reference Manual - Volume 2 - Programming Guide | See the print edition |