Function _Validate_CREATE_Entities

src/ast/ast_validations.c:301–322

Validate each entity referenced in a single path of a CREATE clause.

// Validate each entity referenced in a single path of a CREATE clause.
static AST_Validation _Validate_CREATE_Entities
(
	const cypher_astnode_t *path,  // ast-node (pattern-path)
	rax *defined_aliases           // bound vars
) {
	uint nelems = cypher_ast_pattern_path_nelements(path);
	 // Redeclaration of a node is not allowed only when the path is of length 0, as in: MATCH (a) CREATE (a).
	 // Otherwise, using a defined alias of a node is allowed, as in: MATCH (a) CREATE (a)-[:E]->(:B)
	if(nelems == 1) {
		const cypher_astnode_t *node = cypher_ast_pattern_path_get_element(path, 0);
		const cypher_astnode_t *identifier = cypher_ast_node_pattern_get_identifier(node);
		if(identifier) {
			const char *alias = cypher_ast_identifier_get_name(identifier);
			if(raxFind(defined_aliases, (unsigned char *)alias, strlen(alias)) != raxNotFound) {
				ErrorCtx_SetError("The bound variable '%s' can't be redeclared in a CREATE clause", alias);
				return AST_INVALID;
			}
		}
	}

	return AST_VALID;
}

// make sure an identifier is bound
static AST_Validation _Validate_referred_identifier