ruleutils.c

来自「postgresql8.3.4源码,开源数据库」· C语言 代码 · 共 2,446 行 · 第 1/5 页

			appendStringInfo(&buf, " DELETE");
		findx++;
	}
	if (TRIGGER_FOR_UPDATE(trigrec->tgtype))
	{
		if (findx > 0)
			appendStringInfo(&buf, " OR UPDATE");
		else
			appendStringInfo(&buf, " UPDATE");
	}
	appendStringInfo(&buf, " ON %s ",
					 generate_relation_name(trigrec->tgrelid));

	if (trigrec->tgisconstraint)
	{
		if (trigrec->tgconstrrelid != InvalidOid)
			appendStringInfo(&buf, "FROM %s ",
							 generate_relation_name(trigrec->tgconstrrelid));
		if (!trigrec->tgdeferrable)
			appendStringInfo(&buf, "NOT ");
		appendStringInfo(&buf, "DEFERRABLE INITIALLY ");
		if (trigrec->tginitdeferred)
			appendStringInfo(&buf, "DEFERRED ");
		else
			appendStringInfo(&buf, "IMMEDIATE ");

	}

	if (TRIGGER_FOR_ROW(trigrec->tgtype))
		appendStringInfo(&buf, "FOR EACH ROW ");
	else
		appendStringInfo(&buf, "FOR EACH STATEMENT ");

	appendStringInfo(&buf, "EXECUTE PROCEDURE %s(",
					 generate_function_name(trigrec->tgfoid, 0, NULL));

	if (trigrec->tgnargs > 0)
	{
		bytea	   *val;
		bool		isnull;
		char	   *p;
		int			i;

		val = DatumGetByteaP(fastgetattr(ht_trig,
										 Anum_pg_trigger_tgargs,
										 tgrel->rd_att, &isnull));
		if (isnull)
			elog(ERROR, "tgargs is null for trigger %u", trigid);
		p = (char *) VARDATA(val);
		for (i = 0; i < trigrec->tgnargs; i++)
		{
			if (i > 0)
				appendStringInfo(&buf, ", ");

			/*
			 * We form the string literal according to the prevailing setting
			 * of standard_conforming_strings; we never use E''. User is
			 * responsible for making sure result is used correctly.
			 */
			appendStringInfoChar(&buf, '\'');
			while (*p)
			{
				char		ch = *p++;

				if (SQL_STR_DOUBLE(ch, !standard_conforming_strings))
					appendStringInfoChar(&buf, ch);
				appendStringInfoChar(&buf, ch);
			}
			appendStringInfoChar(&buf, '\'');
			/* advance p to next string embedded in tgargs */
			p++;
		}
	}

	/* We deliberately do not put semi-colon at end */
	appendStringInfo(&buf, ")");

	/* Clean up */
	systable_endscan(tgscan);

	heap_close(tgrel, AccessShareLock);

	PG_RETURN_TEXT_P(string_to_text(buf.data));
}

/* ----------
 * get_indexdef			- Get the definition of an index
 *
 * In the extended version, there is a colno argument as well as pretty bool.
 *	if colno == 0, we want a complete index definition.
 *	if colno > 0, we only want the Nth index key's variable or expression.
 *
 * Note that the SQL-function versions of this omit any info about the
 * index tablespace; this is intentional because pg_dump wants it that way.
 * However pg_get_indexdef_string() includes index tablespace if not default.
 * ----------
 */
Datum
pg_get_indexdef(PG_FUNCTION_ARGS)
{
	Oid			indexrelid = PG_GETARG_OID(0);

	PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, 0,
														   false, 0)));
}

Datum
pg_get_indexdef_ext(PG_FUNCTION_ARGS)
{
	Oid			indexrelid = PG_GETARG_OID(0);
	int32		colno = PG_GETARG_INT32(1);
	bool		pretty = PG_GETARG_BOOL(2);
	int			prettyFlags;

	prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
	PG_RETURN_TEXT_P(string_to_text(pg_get_indexdef_worker(indexrelid, colno,
													   false, prettyFlags)));
}

/* Internal version that returns a palloc'd C string */
char *
pg_get_indexdef_string(Oid indexrelid)
{
	return pg_get_indexdef_worker(indexrelid, 0, true, 0);
}

static char *
pg_get_indexdef_worker(Oid indexrelid, int colno, bool showTblSpc,
					   int prettyFlags)
{
	HeapTuple	ht_idx;
	HeapTuple	ht_idxrel;
	HeapTuple	ht_am;
	Form_pg_index idxrec;
	Form_pg_class idxrelrec;
	Form_pg_am	amrec;
	List	   *indexprs;
	ListCell   *indexpr_item;
	List	   *context;
	Oid			indrelid;
	int			keyno;
	Oid			keycoltype;
	Datum		indclassDatum;
	Datum		indoptionDatum;
	bool		isnull;
	oidvector  *indclass;
	int2vector *indoption;
	StringInfoData buf;
	char	   *str;
	char	   *sep;

	/*
	 * Fetch the pg_index tuple by the Oid of the index
	 */
	ht_idx = SearchSysCache(INDEXRELID,
							ObjectIdGetDatum(indexrelid),
							0, 0, 0);
	if (!HeapTupleIsValid(ht_idx))
		elog(ERROR, "cache lookup failed for index %u", indexrelid);
	idxrec = (Form_pg_index) GETSTRUCT(ht_idx);

	indrelid = idxrec->indrelid;
	Assert(indexrelid == idxrec->indexrelid);

	/* Must get indclass and indoption the hard way */
	indclassDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
									Anum_pg_index_indclass, &isnull);
	Assert(!isnull);
	indclass = (oidvector *) DatumGetPointer(indclassDatum);
	indoptionDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
									 Anum_pg_index_indoption, &isnull);
	Assert(!isnull);
	indoption = (int2vector *) DatumGetPointer(indoptionDatum);

	/*
	 * Fetch the pg_class tuple of the index relation
	 */
	ht_idxrel = SearchSysCache(RELOID,
							   ObjectIdGetDatum(indexrelid),
							   0, 0, 0);
	if (!HeapTupleIsValid(ht_idxrel))
		elog(ERROR, "cache lookup failed for relation %u", indexrelid);
	idxrelrec = (Form_pg_class) GETSTRUCT(ht_idxrel);

	/*
	 * Fetch the pg_am tuple of the index' access method
	 */
	ht_am = SearchSysCache(AMOID,
						   ObjectIdGetDatum(idxrelrec->relam),
						   0, 0, 0);
	if (!HeapTupleIsValid(ht_am))
		elog(ERROR, "cache lookup failed for access method %u",
			 idxrelrec->relam);
	amrec = (Form_pg_am) GETSTRUCT(ht_am);

	/*
	 * Get the index expressions, if any.  (NOTE: we do not use the relcache
	 * versions of the expressions and predicate, because we want to display
	 * non-const-folded expressions.)
	 */
	if (!heap_attisnull(ht_idx, Anum_pg_index_indexprs))
	{
		Datum		exprsDatum;
		bool		isnull;
		char	   *exprsString;

		exprsDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
									 Anum_pg_index_indexprs, &isnull);
		Assert(!isnull);
		exprsString = DatumGetCString(DirectFunctionCall1(textout,
														  exprsDatum));
		indexprs = (List *) stringToNode(exprsString);
		pfree(exprsString);
	}
	else
		indexprs = NIL;

	indexpr_item = list_head(indexprs);

	context = deparse_context_for(get_rel_name(indrelid), indrelid);

	/*
	 * Start the index definition.	Note that the index's name should never be
	 * schema-qualified, but the indexed rel's name may be.
	 */
	initStringInfo(&buf);

	if (!colno)
		appendStringInfo(&buf, "CREATE %sINDEX %s ON %s USING %s (",
						 idxrec->indisunique ? "UNIQUE " : "",
						 quote_identifier(NameStr(idxrelrec->relname)),
						 generate_relation_name(indrelid),
						 quote_identifier(NameStr(amrec->amname)));

	/*
	 * Report the indexed attributes
	 */
	sep = "";
	for (keyno = 0; keyno < idxrec->indnatts; keyno++)
	{
		AttrNumber	attnum = idxrec->indkey.values[keyno];
		int16		opt = indoption->values[keyno];

		if (!colno)
			appendStringInfoString(&buf, sep);
		sep = ", ";

		if (attnum != 0)
		{
			/* Simple index column */
			char	   *attname;

			attname = get_relid_attribute_name(indrelid, attnum);
			if (!colno || colno == keyno + 1)
				appendStringInfoString(&buf, quote_identifier(attname));
			keycoltype = get_atttype(indrelid, attnum);
		}
		else
		{
			/* expressional index */
			Node	   *indexkey;

			if (indexpr_item == NULL)
				elog(ERROR, "too few entries in indexprs list");
			indexkey = (Node *) lfirst(indexpr_item);
			indexpr_item = lnext(indexpr_item);
			/* Deparse */
			str = deparse_expression_pretty(indexkey, context, false, false,
											prettyFlags, 0);
			if (!colno || colno == keyno + 1)
			{
				/* Need parens if it's not a bare function call */
				if (indexkey && IsA(indexkey, FuncExpr) &&
				 ((FuncExpr *) indexkey)->funcformat == COERCE_EXPLICIT_CALL)
					appendStringInfoString(&buf, str);
				else
					appendStringInfo(&buf, "(%s)", str);
			}
			keycoltype = exprType(indexkey);
		}

		/* Provide decoration only in the colno=0 case */
		if (!colno)
		{
			/* Add the operator class name, if not default */
			get_opclass_name(indclass->values[keyno], keycoltype, &buf);

			/* Add options if relevant */
			if (amrec->amcanorder)
			{
				/* if it supports sort ordering, report DESC and NULLS opts */
				if (opt & INDOPTION_DESC)
				{
					appendStringInfo(&buf, " DESC");
					/* NULLS FIRST is the default in this case */
					if (!(opt & INDOPTION_NULLS_FIRST))
						appendStringInfo(&buf, " NULLS LAST");
				}
				else
				{
					if (opt & INDOPTION_NULLS_FIRST)
						appendStringInfo(&buf, " NULLS FIRST");
				}
			}
		}
	}

	if (!colno)
	{
		appendStringInfoChar(&buf, ')');

		/*
		 * If it has options, append "WITH (options)"
		 */
		str = flatten_reloptions(indexrelid);
		if (str)
		{
			appendStringInfo(&buf, " WITH (%s)", str);
			pfree(str);
		}

		/*
		 * If it's in a nondefault tablespace, say so, but only if requested
		 */
		if (showTblSpc)
		{
			Oid			tblspc;

			tblspc = get_rel_tablespace(indexrelid);
			if (OidIsValid(tblspc))
				appendStringInfo(&buf, " TABLESPACE %s",
							  quote_identifier(get_tablespace_name(tblspc)));
		}

		/*
		 * If it's a partial index, decompile and append the predicate
		 */
		if (!heap_attisnull(ht_idx, Anum_pg_index_indpred))
		{
			Node	   *node;
			Datum		predDatum;
			bool		isnull;
			char	   *predString;

			/* Convert text string to node tree */
			predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
										Anum_pg_index_indpred, &isnull);
			Assert(!isnull);
			predString = DatumGetCString(DirectFunctionCall1(textout,
															 predDatum));
			node = (Node *) stringToNode(predString);
			pfree(predString);

			/* Deparse */
			str = deparse_expression_pretty(node, context, false, false,
											prettyFlags, 0);
			appendStringInfo(&buf, " WHERE %s", str);
		}
	}

	/* Clean up */
	ReleaseSysCache(ht_idx);
	ReleaseSysCache(ht_idxrel);
	ReleaseSysCache(ht_am);

	return buf.data;
}


/*
 * pg_get_constraintdef
 *
 * Returns the definition for the constraint, ie, everything that needs to
 * appear after "ALTER TABLE ... ADD CONSTRAINT <constraintname>".
 */
Datum
pg_get_constraintdef(PG_FUNCTION_ARGS)
{
	Oid			constraintId = PG_GETARG_OID(0);

	PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
																false, 0)));
}

Datum
pg_get_constraintdef_ext(PG_FUNCTION_ARGS)
{
	Oid			constraintId = PG_GETARG_OID(0);
	bool		pretty = PG_GETARG_BOOL(1);
	int			prettyFlags;

	prettyFlags = pretty ? PRETTYFLAG_PAREN | PRETTYFLAG_INDENT : 0;
	PG_RETURN_TEXT_P(string_to_text(pg_get_constraintdef_worker(constraintId,
													   false, prettyFlags)));
}

/* Internal version that returns a palloc'd C string */
char *
pg_get_constraintdef_string(Oid constraintId)
{
	return pg_get_constraintdef_worker(constraintId, true, 0);
}

static char *
pg_get_constraintdef_worker(Oid constraintId, bool fullCommand,
							int prettyFlags)
{
	HeapTuple	tup;
	Form_pg_constraint conForm;
	StringInfoData buf;

	tup = SearchSysCache(CONSTROID,
						 ObjectIdGetDatum(constraintId),
						 0, 0, 0);
	if (!HeapTupleIsValid(tup)) /* should not happen */
		elog(ERROR, "cache lookup failed for constraint %u", constraintId);
	conForm = (Form_pg_constraint) GETSTRUCT(tup);

	initStringInfo(&buf);

	if (fullCommand && OidIsValid(conForm->conrelid))
	{
		appendStringInfo(&buf, "ALTER TABLE ONLY %s ADD CONSTRAINT %s ",
						 generate_relation_name(conForm->conrelid),
						 quote_identifier(NameStr(conForm->conname)));
	}

	switch (conForm->contype)
	{
		case CONSTRAINT_FOREIGN:
			{
				Datum		val;
				bool		isnull;
				const char *string;

				/* Start off the constraint definition */
				appendStringInfo(&buf, "FOREIGN KEY (");

				/* Fetch and build referencing-column list */
				val = SysCacheGetAttr(CONSTROID, tup,
									  Anum_pg_constraint_conkey, &isnull);
				if (isnull)
					elog(ERROR, "null conkey for constraint %u",
						 constraintId);

				decompile_column_index_array(val, conForm->conrelid, &buf);

				/* add foreign relation name */
				appendStringInfo(&buf, ") REFERENCES %s(",
								 generate_relation_name(conForm->confrelid));

				/* Fetch and build referenced-column list */
				val = SysCacheGetAttr(CONSTROID, tup,
									  Anum_pg_constraint_confkey, &isnull);
				if (isnull)
					elog(ERROR, "null confkey for constraint %u",
						 constraintId);

				decompile_column_index_array(val, conForm->confrelid, &buf);

				appendStringInfo(&buf, ")");

				/* Add match type */
				switch (conForm->confmatchtype)
				{
					case FKCONSTR_MATCH_FULL:
						string = " MATCH FULL";
						break;
					case FKCONSTR_MATCH_PARTIAL:
						string = " MATCH PARTIAL";
						break;
					case FKCONSTR_MATCH_UNSPECIFIED:
						string = "";
						break;
					default:
						elog(ERROR, "unrecognized confmatchtype: %d",
							 conForm->confmatchtype);
						string = "";	/* keep compiler quiet */
						break;
				}
				appendStringInfoString(&buf, string);

				/* Add ON UPDATE and ON DELETE clauses, if needed */
				switch (conForm->confupdtype)
				{
					case FKCONSTR_ACTION_NOACTION:
						string = NULL;	/* suppress default */
						break;
					case FKCONSTR_ACTION_RESTRICT:
						string = "RESTRICT";