The pg_attrdef catalog provides information about column default expressions and generation expressions.
| Column name | Data type | Description |
|---|---|---|
oid |
oid |
A row identifier. |
adrelid |
oid (references pg_class.oid) |
The table to which this column belongs. |
adnum |
int2 (references pg_attribute.attnum) |
The number of the column. |
adbin |
pg_node_tree |
The column default or generated expression in the nodeToString() representation. Note: Use pg_get_expr(adbin, adrelid) to convert it into a standard SQL expression. |