The catalog pg_attrdef stores column default values. The main information about columns is stored in pg_attribute (see below). Only columns that explicitly specify a default value (when the table is created or the column is added) will have an entry here.
Table 49-6. pg_attrdef Columns
|oid||oid||Row identifier (hidden attribute; must be explicitly selected)|
|adrelid||oid||pg_class.oid||The table this column belongs to|
|adnum||int2||pg_attribute.attnum||The number of the column|
|adbin||pg_node_tree||The internal representation of the column default value|
|adsrc||text||A human-readable representation of the default value|
The adsrc field is historical,
and is best not used, because it does not track outside changes
that might affect the representation of the default value.
Reverse-compiling the adbin field
pg_get_expr for example) is a
better way to display the default value.
Please use this form to add your own comments regarding your experience with particular features of PostgreSQL, clarifications of the documentation, or hints for other users. Please note, this is not a support forum, and your IP address will be logged. If you have a question or need help, please see the faq, try a mailing list, or join us on IRC. Note that submissions containing URLs or other keywords commonly found in 'spam' comments may be silently discarded. Please contact the webmaster if you think this is happening to you in error.
Proceed to the comment form.