C. SQL 關鍵字

​Table C.1 lists all tokens that are key words in the SQL standard and in PostgreSQL 11devel. Background information can be found in Section 4.1.1. (For space reasons, only the latest two versions of the SQL standard, and SQL-92 for historical comparison, are included. The differences between those and the other intermediate standard versions are small.)
SQL distinguishes between reserved and non-reserved key words. According to the standard, reserved key words are the only real key words; they are never allowed as identifiers. Non-reserved key words only have a special meaning in particular contexts and can be used as identifiers in other contexts. Most non-reserved key words are actually the names of built-in tables and functions specified by SQL. The concept of non-reserved key words essentially only exists to declare that some predefined meaning is attached to a word in some contexts.
In the PostgreSQL parser life is a bit more complicated. There are several different classes of tokens ranging from those that can never be used as an identifier to those that have absolutely no special status in the parser as compared to an ordinary identifier. (The latter is usually the case for functions specified by SQL.) Even reserved key words are not completely reserved in PostgreSQL, but can be used as column labels (for example, SELECT 55 AS CHECK, even though CHECK is a reserved key word).
In Table C.1 in the column for PostgreSQL we classify as “non-reserved” those key words that are explicitly known to the parser but are allowed as column or table names. Some key words that are otherwise non-reserved cannot be used as function or data type names and are marked accordingly. (Most of these words represent built-in functions or data types with special syntax. The function or type is still available but it cannot be redefined by the user.) Labeled “reserved” are those tokens that are not allowed as column or table names. Some reserved key words are allowable as names for functions or data types; this is also shown in the table. If not so marked, a reserved key word is only allowed as an “AS” column label name.
As a general rule, if you get spurious parser errors for commands that contain any of the listed key words as an identifier you should try to quote the identifier to see if the problem goes away.
It is important to understand before studying Table C.1 that the fact that a key word is not reserved in PostgreSQL does not mean that the feature related to the word is not implemented. Conversely, the presence of a key word does not indicate the existence of a feature.
Table C.1. SQL Key Words
Key Word
PostgreSQL
SQL:2011
SQL:2008
SQL-92
A
 
non-reserved
non-reserved
 
ABORT
non-reserved
 
 
 
ABS
 
reserved
reserved
 
ABSENT
 
non-reserved
non-reserved
 
ABSOLUTE
non-reserved
non-reserved
non-reserved
reserved
ACCESS
non-reserved
 
 
 
ACCORDING
 
non-reserved
non-reserved
 
ACTION
non-reserved
non-reserved
non-reserved
reserved
ADA
 
non-reserved
non-reserved
non-reserved
ADD
non-reserved
non-reserved
non-reserved
reserved
ADMIN
non-reserved
non-reserved
non-reserved
 
AFTER
non-reserved
non-reserved
non-reserved
 
AGGREGATE
non-reserved
 
 
 
ALL
reserved
reserved
reserved
reserved
ALLOCATE
 
reserved
reserved
reserved
ALSO
non-reserved
 
 
 
ALTER
non-reserved
reserved
reserved
reserved
ALWAYS
non-reserved
non-reserved
non-reserved
 
ANALYSE
reserved
 
 
 
ANALYZE
reserved
 
 
 
AND
reserved
reserved
reserved
reserved
ANY
reserved
reserved
reserved
reserved
ARE
 
reserved
reserved
reserved
ARRAY
reserved
reserved
reserved
 
ARRAY_AGG
 
reserved
reserved
 
ARRAY_MAX_CARDINALITY
 
reserved
 
 
AS
reserved
reserved
reserved
reserved
ASC
reserved
non-reserved
non-reserved
reserved
ASENSITIVE
 
reserved
reserved
 
ASSERTION
non-reserved
non-reserved
non-reserved
reserved
ASSIGNMENT
non-reserved
non-reserved
non-reserved
 
ASYMMETRIC
reserved
reserved
reserved
 
AT
non-reserved
reserved
reserved
reserved
ATOMIC
 
reserved
reserved
 
ATTACH
non-reserved
 
 
 
ATTRIBUTE
non-reserved
non-reserved
non-reserved
 
ATTRIBUTES
 
non-reserved
non-reserved
 
AUTHORIZATION
reserved (can be function or type)
reserved
reserved
reserved
AVG
 
reserved
reserved
reserved
BACKWARD
non-reserved
 
 
 
BASE64
 
non-reserved
non-reserved
 
BEFORE
non-reserved
non-reserved
non-reserved
 
BEGIN
non-reserved
reserved
reserved
reserved
BEGIN_FRAME
 
reserved
 
 
BEGIN_PARTITION
 
reserved
 
 
BERNOULLI
 
non-reserved
non-reserved
 
BETWEEN
non-reserved (cannot be function or type)
reserved
reserved
reserved
BIGINT
non-reserved (cannot be function or type)
reserved
reserved
 
BINARY
reserved (can be function or type)
reserved
reserved
 
BIT
non-reserved (cannot be function or type)
 
 
reserved
BIT_LENGTH
 
 
 
reserved
BLOB
 
reserved
reserved
 
BLOCKED
 
non-reserved
non-reserved
 
BOM
 
non-reserved
non-reserved
 
BOOLEAN
non-reserved (cannot be function or type)
reserved
reserved
 
BOTH
reserved
reserved
reserved
reserved
BREADTH
 
non-reserved
non-reserved
 
BY
non-reserved
reserved
reserved
reserved
C
 
non-reserved
non-reserved
non-reserved
CACHE
non-reserved
 
 
 
CALL
 
reserved
reserved
 
CALLED
non-reserved
reserved
reserved
 
CARDINALITY
 
reserved
reserved
 
CASCADE
non-reserved
non-reserved
non-reserved
reserved
CASCADED
non-reserved
reserved
reserved
reserved
CASE
reserved
reserved
reserved
reserved
CAST
reserved
reserved
reserved
reserved
CATALOG
non-reserved
non-reserved
non-reserved
reserved
CATALOG_NAME
 
non-reserved
non-reserved
non-reserved
CEIL
 
reserved
reserved
 
CEILING
 
reserved
reserved
 
CHAIN
non-reserved
non-reserved
non-reserved
 
CHAR
non-reserved (cannot be function or type)
reserved
reserved
reserved
CHARACTER
non-reserved (cannot be function or type)
reserved
reserved
reserved
CHARACTERISTICS
non-reserved
non-reserved
non-reserved
 
CHARACTERS
 
non-reserved
non-reserved
 
CHARACTER_LENGTH
 
reserved
reserved
reserved
CHARACTER_SET_CATALOG
 
non-reserved
non-reserved
non-reserved
CHARACTER_SET_NAME
 
non-reserved
non-reserved
non-reserved
CHARACTER_SET_SCHEMA
 
non-reserved
non-reserved
non-reserved
CHAR_LENGTH
 
reserved
reserved
reserved
CHECK
reserved
reserved
reserved
reserved
CHECKPOINT
non-reserved
 
 
 
CLASS
non-reserved
 
 
 
CLASS_ORIGIN
 
non-reserved
non-reserved
non-reserved
CLOB
 
reserved
reserved
 
CLOSE
non-reserved
reserved
reserved
reserved
CLUSTER
non-reserved
 
 
 
COALESCE
non-reserved (cannot be function or type)
reserved
reserved
reserved
COBOL
 
non-reserved
non-reserved
non-reserved
COLLATE
reserved
reserved
reserved
reserved
COLLATION
reserved (can be function or type)
non-reserved
non-reserved
reserved
COLLATION_CATALOG
 
non-reserved
non-reserved
non-reserved
COLLATION_NAME
 
non-reserved
non-reserved
non-reserved
COLLATION_SCHEMA
 
non-reserved
non-reserved
non-reserved
COLLECT
 
reserved
reserved
 
COLUMN
reserved
reserved
reserved
reserved
COLUMNS
non-reserved
non-reserved
non-reserved
 
COLUMN_NAME
 
non-reserved
non-reserved
non-reserved
COMMAND_FUNCTION
 
non-reserved
non-reserved
non-reserved
COMMAND_FUNCTION_CODE
 
non-reserved
non-reserved
 
COMMENT
non-reserved
 
 
 
COMMENTS
non-reserved
 
 
 
COMMIT
non-reserved
reserved
reserved
reserved
COMMITTED
non-reserved
non-reserved
non-reserved
non-reserved
CONCURRENTLY
reserved (can be function or type)
 
 
 
CONDITION
 
reserved
reserved
 
CONDITION_NUMBER
 
non-reserved
non-reserved
non-reserved
CONFIGURATION
non-reserved
 
 
 
CONFLICT
non-reserved
 
 
 
CONNECT
 
reserved
reserved
reserved
CONNECTION
non-reserved
non-reserved
non-reserved
reserved
CONNECTION_NAME
 
non-reserved
non-reserved
non-reserved
CONSTRAINT
reserved
reserved
reserved
reserved
CONSTRAINTS
non-reserved
non-reserved
non-reserved
reserved
CONSTRAINT_CATALOG
 
non-reserved
non-reserved
non-reserved
CONSTRAINT_NAME
 
non-reserved
non-reserved
non-reserved
CONSTRAINT_SCHEMA
 
non-reserved
non-reserved
non-reserved
CONSTRUCTOR
 
non-reserved
non-reserved
 
CONTAINS
 
reserved
non-reserved
 
CONTENT
non-reserved
non-reserved
non-reserved
 
CONTINUE
non-reserved
non-reserved
non-reserved
reserved
CONTROL
 
non-reserved
non-reserved
 
CONVERSION
non-reserved
 
 
 
CONVERT
 
reserved
reserved
reserved
COPY
non-reserved
 
 
 
CORR
 
reserved
reserved
 
CORRESPONDING
 
reserved
reserved
reserved
COST
non-reserved
 
 
 
COUNT
 
reserved
reserved
reserved
COVAR_POP
 
reserved
reserved
 
COVAR_SAMP
 
reserved
reserved
 
CREATE
reserved
reserved
reserved
reserved
CROSS
reserved (can be function or type)
reserved
reserved
reserved
CSV
non-reserved
 
 
 
CUBE
non-reserved
reserved
reserved
 
CUME_DIST
 
reserved
reserved
 
CURRENT
non-reserved
reserved
reserved
reserved
CURRENT_CATALOG
reserved
reserved
reserved
 
CURRENT_DATE
reserved
reserved
reserved
reserved
CURRENT_DEFAULT_TRANSFORM_GROUP
 
reserved
reserved
 
CURRENT_PATH
 
reserved
reserved
 
CURRENT_ROLE
reserved
reserved
reserved
 
CURRENT_ROW
 
reserved
 
 
CURRENT_SCHEMA
reserved (can be function or type)
reserved
reserved
 
CURRENT_TIME
reserved
reserved
reserved
reserved
CURRENT_TIMESTAMP
reserved
reserved
reserved
reserved
CURRENT_TRANSFORM_GROUP_FOR_TYPE
 
reserved
reserved
 
CURRENT_USER
reserved
reserved
reserved
reserved
CURSOR
non-reserved
reserved
reserved
reserved
CURSOR_NAME
 
non-reserved
non-reserved
non-reserved
CYCLE
non-reserved
reserved
reserved
 
DATA
non-reserved
non-reserved
non-reserved
non-reserved

B.5. History of Units

D. SQL 相容性

Last updated -1

Key Word	PostgreSQL	SQL:2011	SQL:2008	SQL-92
`A`		non-reserved	non-reserved
`ABORT`	non-reserved
`ABS`		reserved	reserved
`ABSENT`		non-reserved	non-reserved
`ABSOLUTE`	non-reserved	non-reserved	non-reserved	reserved
`ACCESS`	non-reserved
`ACCORDING`		non-reserved	non-reserved
`ACTION`	non-reserved	non-reserved	non-reserved	reserved
`ADA`		non-reserved	non-reserved	non-reserved
`ADD`	non-reserved	non-reserved	non-reserved	reserved
`ADMIN`	non-reserved	non-reserved	non-reserved
`AFTER`	non-reserved	non-reserved	non-reserved
`AGGREGATE`	non-reserved
`ALL`	reserved	reserved	reserved	reserved
`ALLOCATE`		reserved	reserved	reserved
`ALSO`	non-reserved
`ALTER`	non-reserved	reserved	reserved	reserved
`ALWAYS`	non-reserved	non-reserved	non-reserved
`ANALYSE`	reserved
`ANALYZE`	reserved
`AND`	reserved	reserved	reserved	reserved
`ANY`	reserved	reserved	reserved	reserved
`ARE`		reserved	reserved	reserved
`ARRAY`	reserved	reserved	reserved
`ARRAY_AGG`		reserved	reserved
`ARRAY_MAX_CARDINALITY`		reserved
`AS`	reserved	reserved	reserved	reserved
`ASC`	reserved	non-reserved	non-reserved	reserved
`ASENSITIVE`		reserved	reserved
`ASSERTION`	non-reserved	non-reserved	non-reserved	reserved
`ASSIGNMENT`	non-reserved	non-reserved	non-reserved
`ASYMMETRIC`	reserved	reserved	reserved
`AT`	non-reserved	reserved	reserved	reserved
`ATOMIC`		reserved	reserved
`ATTACH`	non-reserved
`ATTRIBUTE`	non-reserved	non-reserved	non-reserved
`ATTRIBUTES`		non-reserved	non-reserved
`AUTHORIZATION`	reserved (can be function or type)	reserved	reserved	reserved
`AVG`		reserved	reserved	reserved
`BACKWARD`	non-reserved
`BASE64`		non-reserved	non-reserved
`BEFORE`	non-reserved	non-reserved	non-reserved
`BEGIN`	non-reserved	reserved	reserved	reserved
`BEGIN_FRAME`		reserved
`BEGIN_PARTITION`		reserved
`BERNOULLI`		non-reserved	non-reserved
`BETWEEN`	non-reserved (cannot be function or type)	reserved	reserved	reserved
`BIGINT`	non-reserved (cannot be function or type)	reserved	reserved
`BINARY`	reserved (can be function or type)	reserved	reserved
`BIT`	non-reserved (cannot be function or type)			reserved
`BIT_LENGTH`				reserved
`BLOB`		reserved	reserved
`BLOCKED`		non-reserved	non-reserved
`BOM`		non-reserved	non-reserved
`BOOLEAN`	non-reserved (cannot be function or type)	reserved	reserved
`BOTH`	reserved	reserved	reserved	reserved
`BREADTH`		non-reserved	non-reserved
`BY`	non-reserved	reserved	reserved	reserved