51.6. pg_attrdef

51.6. `pg_attrdef`
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The catalog pg_attrdef stores column default values. The main information about columns is stored in pg_attribute . Only columns for which a default value has been explicitly set will have an entry here.

Table 51.6. pg_attrdef Columns

Column Type Description
`oid` `oid` Row identifier
`adrelid` `oid` (references `pg_class` . `oid` ) The table this column belongs to
`adnum` `int2` (references `pg_attribute` . `attnum` ) The number of the column
`adbin` `pg_node_tree` The column default value, in `nodeToString()` representation. Use `pg_get_expr(adbin, adrelid)` to convert it to an SQL expression.

Column Type

Description

oid oid

Row identifier

adrelid oid (references pg_class . oid )

The table this column belongs to

adnum int2 (references pg_attribute . attnum )

The number of the column

adbin pg_node_tree

The column default value, in nodeToString() representation. Use pg_get_expr(adbin, adrelid) to convert it to an SQL expression.

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