<entry><structfield>adbin</structfield></entry>

<entry><type>pg_node_tree</type></entry>

<entry></entry>

<entry>The internal representation of the column default value</entry>

</row>

<row>

<entry><structfield>adsrc</structfield></entry>

<entry><type>text</type></entry>

<entry></entry>

<entry>A human-readable representation of the default value</entry>

<entry>The column default value, in <function>nodeToString()</function>

representation. Use <literal>pg_get_expr(adbin, adrelid)</literal> to

convert it to an SQL expression.</entry>

</row>

</tbody>

</tgroup>

</table>

<para>

The <structfield>adsrc</structfield> 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

<structfield>adbin</structfield> field (with <function>pg_get_expr</function> for

example) is a better way to display the default value.

</para>

</sect1>

Node*expr,boolis_internal,booladd_column_mode)

{

char*adbin;

char*adsrc;

Relationadrel;

HeapTupletuple;

Datumvalues[4];

adbin=nodeToString(expr);

adsrc=deparse_expression(expr,

deparse_context_for(RelationGetRelationName(rel),

RelationGetRelid(rel)),

false, false);

values[Anum_pg_attrdef_adrelid-1]=RelationGetRelid(rel);

values[Anum_pg_attrdef_adnum-1]=attnum;

values[Anum_pg_attrdef_adbin-1]=CStringGetTextDatum(adbin);

values[Anum_pg_attrdef_adsrc-1]=CStringGetTextDatum(adsrc);

adrel=heap_open(AttrDefaultRelationId,RowExclusiveLock);

pfree(DatumGetPointer(values[Anum_pg_attrdef_adbin-1]));

pfree(DatumGetPointer(values[Anum_pg_attrdef_adsrc-1]));

heap_freetuple(tuple);

pfree(adbin);

pfree(adsrc);

pg_node_treeadbinBKI_FORCE_NOT_NULL;/* nodeToString representation of default */

textadsrcBKI_FORCE_NOT_NULL;/* human-readable representation of default */

}FormData_pg_attrdef;