keywords and reserved words

docs-2.0/3.ngql-guide/1.nGQL-overview/keywords-and-reserved-words.md

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+# Keywords
+
+Keywords have significance in nGQL. It can be classified into reserved keywords and non-reserved keywords.
+
+Non-reserved keywords are permitted as identifiers without quoting. To use reserved keywords as identifiers, quote them with backticks such as `AND`.
+
+!!! Note
+
+    Keywords are case-insensitive.
+
+```ngql
+nebula> CREATE TAG TAG(name string);
+[ERROR (-7)]: SyntaxError: syntax error near `TAG'
+
+nebula> CREATE TAG `TAG` (name string);
+Execution succeeded
+
+nebula> CREATE TAG SPACE(name string);
+Execution succeeded
+```
+
+- `TAG` is a reserved keyword. To use `TAG` as an identifier, you must quote it with backticks.
+
+- `SPACE` is a non-reserved keyword. You can use it as an identifier without quoting it.
+
+## Reserved keywords
+
+```ngql
+ADD
+ALTER
+AND
+AS
+ASC
+BALANCE
+BOOL
+BY
+CASE
+CHANGE
+COMPACT
+CREATE
+DATE
+DATETIME
+DELETE
+DESC
+DESCRIBE
+DISTINCT
+DOUBLE
+DOWNLOAD
+DROP
+EDGE
+EDGES
+EXISTS
+EXPLAIN
+FETCH
+FIND
+FIXED_STRING
+FLOAT
+FLUSH
+FORMAT
+FROM
+GET
+GO
+GRANT
+IF
+IN
+INDEX
+INDEXES
+INGEST
+INSERT
+INT
+INT16
+INT32
+INT64
+INT8
+INTERSECT
+IS
+LIMIT
+LOOKUP
+MATCH
+MINUS
+NO
+NOT
+NULL
+OF
+OFFSET
+ON
+OR
+ORDER
+OVER
+OVERWRITE
+PROFILE
+PROP
+REBUILD
+RECOVER
+REMOVE
+RETURN
+REVERSELY
+REVOKE
+SET
+SHOW
+STEP
+STEPS
+STOP
+STRING
+SUBMIT
+TAG
+TAGS
+TIME
+TIMESTAMP
+TO
+UNION
+UPDATE
+UPSERT
+UPTO
+USE
+VERTEX
+WHEN
+WHERE
+WITH
+XOR
+YIELD
+```
+
+## Non-reserved keywords
+
+```ngql
+ACCOUNT
+ADMIN
+ALL
+ANY
+ATOMIC_EDGE
+AUTO
+AVG
+BIDIRECT
+BIT_AND
+BIT_OR
+BIT_XOR
+BOTH
+CHARSET
+CLIENTS
+COLLATE
+COLLATION
+COLLECT
+COLLECT_SET
+CONFIGS
+CONTAINS
+COUNT
+COUNT_DISTINCT
+DATA
+DBA
+DEFAULT
+ELASTICSEARCH
+ELSE
+END
+ENDS
+FALSE
+FORCE
+FUZZY
+GOD
+GRAPH
+GROUP
+GROUPS
+GUEST
+HDFS
+HOST
+HOSTS
+INTO
+JOB
+JOBS
+LEADER
+LISTENER
+MAX
+META
+MIN
+NOLOOP
+NONE
+OPTIONAL
+OUT
+PART
+PARTITION_NUM
+PARTS
+PASSWORD
+PATH
+PLAN
+PREFIX
+REGEXP
+REPLICA_FACTOR
+RESET
+ROLE
+ROLES
+SEARCH
+SERVICE
+SHORTEST
+SIGN
+SINGLE
+SKIP
+SNAPSHOT
+SNAPSHOTS
+SPACE
+SPACES
+STARTS
+STATS
+STATUS
+STD
+STORAGE
+SUBGRAPH
+SUM
+TEXT
+TEXT_SEARCH
+THEN
+TRUE
+TTL_COL
+TTL_DURATION
+UNWIND
+USER
+USERS
+UUID
+VALUE
+VALUES
+VID_TYPE
+WILDCARD
+ZONE
+ZONES
+```