Reserved keywords in UQL are terms with predefined meanings that influence query behavior. These words cannot be used as identifiers for aliases, schemas, properties, or other user-defined elements.
The following are reserved keywords in UQL:
| Category | Words  | 
|---|---|
| System Property | _id, _uuid, _from, _to, _from_uuid, _to_uuid | 
| System Table Alias | _graph, _graph_shard_N _nodeSchema, _nodeSchema_shard_N _edgeSchema, _edgeSchema_shard_N, _graphCount, _nodeProperty, _nodeProperty_shard_N, _edgeProperty, _edgeProperty_shard_N, _nodeIndex, _edgeIndex, _nodeFulltext, _edgeFulltext, _statistic, _top, _job, _policy, _user, _privilege, _algoList, _extaList, _hdcGraphList, _projectionList, _vector, _nodeVectorIndex, _edgeVectorIndex, _backupList | 
| System Alias | this,prev_n,prev_e | 
| Operator[1] | IN, NIN, CONTAINS, XOR, DISTINCT, IS NULL, IS NOT NULL | 
| Statement[1] | GROUP BY, ORDER BY, SKIP, LIMIT, WHERE, RETURN, WITH, UNCOLLECT, UNION, UNION ALL, CALL, OPTIONAL, EXPLAIN | 
| Modifiers[1] | AS, ASC, DESC | 
| Expression[1] | CASE, WHEN, THEN, ELSE, END | 
[1] Those reserved words are case-insensitive.