Function Schema_GetConstraint

src/schema/schema.c:649–694

retrieves constraint returns NULL if constraint was not found

// retrieves constraint 
// returns NULL if constraint was not found
Constraint Schema_GetConstraint
(
	const Schema *s,            // schema from which to get constraint
	ConstraintType t,           // constraint type
	const Attribute_ID *attrs,  // constraint attributes
	uint attr_count             // number of attributes
) {
	// validations
	ASSERT(s          != NULL);
	ASSERT(attrs      != NULL);
	ASSERT(attr_count > 0);

	// search for constraint
	uint n = array_len(s->constraints);
	for(uint i = 0; i < n; i++) {
		Constraint c = s->constraints[i];

		// check constraint type
		if(Constraint_GetType(c) != t) {
			continue;
		}

		// make sure constraint attribute count matches
		const Attribute_ID *c_attrs;
		uint n = Constraint_GetAttributes(c, &c_attrs, NULL);
		if(n != attr_count) {
			continue;
		}

		// match each attribute
		bool match = true;  // optimistic
		for(uint j = 0; j < n; j++) {
			if(c_attrs[j] != attrs[j]) {
				match = false;
				break;
			}
		}

		if(match == true) {
			return c;
		}
	}

	// no constraint was found
	return NULL;
}

// get all constraints in schema
const Constraint *Schema_GetConstraints