Function dumpDomain

src/bin/pg_dump/pg_dump.c:12440–12610

* dumpDomain * writes out to fout the queries to recreate a user-defined domain */

 *	  writes out to fout the queries to recreate a user-defined domain
 */
static void
dumpDomain(Archive *fout, const TypeInfo *tyinfo)
{
	DumpOptions *dopt = fout->dopt;
	PQExpBuffer q = createPQExpBuffer();
	PQExpBuffer delq = createPQExpBuffer();
	PQExpBuffer query = createPQExpBuffer();
	PGresult   *res;
	int			i;
	char	   *qtypname;
	char	   *qualtypname;
	char	   *typnotnull;
	char	   *typdefn;
	char	   *typdefault;
	Oid			typcollation;
	bool		typdefault_is_literal = false;

	/* Fetch domain specific details */
	if (fout->remoteVersion >= 90100)
	{
		/* typcollation is new in 9.1 */
		appendPQExpBuffer(query, "SELECT t.typnotnull, "
						  "pg_catalog.format_type(t.typbasetype, t.typtypmod) AS typdefn, "
						  "pg_catalog.pg_get_expr(t.typdefaultbin, 'pg_catalog.pg_type'::pg_catalog.regclass) AS typdefaultbin, "
						  "t.typdefault, "
						  "CASE WHEN t.typcollation <> u.typcollation "
						  "THEN t.typcollation ELSE 0 END AS typcollation "
						  "FROM pg_catalog.pg_type t "
						  "LEFT JOIN pg_catalog.pg_type u ON (t.typbasetype = u.oid) "
						  "WHERE t.oid = '%u'::pg_catalog.oid",
						  tyinfo->dobj.catId.oid);
	}
	else
	{
		appendPQExpBuffer(query, "SELECT typnotnull, "
						  "pg_catalog.format_type(typbasetype, typtypmod) AS typdefn, "
						  "pg_catalog.pg_get_expr(typdefaultbin, 'pg_catalog.pg_type'::pg_catalog.regclass) AS typdefaultbin, "
						  "typdefault, 0 AS typcollation "
						  "FROM pg_catalog.pg_type "
						  "WHERE oid = '%u'::pg_catalog.oid",
						  tyinfo->dobj.catId.oid);
	}

	res = ExecuteSqlQueryForSingleRow(fout, query->data);

	typnotnull = PQgetvalue(res, 0, PQfnumber(res, "typnotnull"));
	typdefn = PQgetvalue(res, 0, PQfnumber(res, "typdefn"));
	if (!PQgetisnull(res, 0, PQfnumber(res, "typdefaultbin")))
		typdefault = PQgetvalue(res, 0, PQfnumber(res, "typdefaultbin"));
	else if (!PQgetisnull(res, 0, PQfnumber(res, "typdefault")))
	{
		typdefault = PQgetvalue(res, 0, PQfnumber(res, "typdefault"));
		typdefault_is_literal = true;	/* it needs quotes */
	}
	else
		typdefault = NULL;
	typcollation = atooid(PQgetvalue(res, 0, PQfnumber(res, "typcollation")));