SELECT 后的保留关键字

Question

在字段列表之前的 SQL 中的 SELECT 语句之后，有没有办法知道所有可能的（可接受的）关键字？

编辑

参考数据库是MySQL

Answer 1

Reserved Keywords in MySql

关键字是在 SQL 中具有重要意义的词。某些关键字，如 SELECT、DELETE 或 BIGINT，是保留的，需要特殊处理才能用作标识符，如 table 和列名。这可能也适用于内置函数的名称。

允许非保留关键字作为标识符而不用引号。如果您引用保留字，则允许将其用作标识符

Reserved Keywords 在 MSSQL 服务器中：

Microsoft SQL 服务器使用保留关键字来定义、操作和访问数据库。保留关键字是 Transact-SQL 语言语法的一部分，SQL 服务器使用它来解析和理解 Transact-SQL 语句和批处理。

尽管在语法上可以使用 SQL 服务器保留关键字作为 Transact-SQL 脚本中的标识符和对象名称，但您只能通过使用分隔标识符来执行此操作。

Answer 2

查看文档。

例如：mysql 5.0 documentation

Answer 3

PostgreSQL9.4

http://www.postgresql.org/docs/9.4/static/sql-select.html

[ WITH [ RECURSIVE ] with_query [, ...] ]
SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ]
    [ * | expression [ [ AS ] output_name ] [, ...] ]
    [ FROM from_item [, ...] ]
    [ WHERE condition ]
    [ GROUP BY expression [, ...] ]
    [ HAVING condition [, ...] ]
    [ WINDOW window_name AS ( window_definition ) [, ...] ]
    [ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ] select ]
    [ ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...] ]
    [ LIMIT { count | ALL } ]
    [ OFFSET start [ ROW | ROWS ] ]
    [ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ]
    [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT ] [...] ]

where from_item can be one of:

    [ ONLY ] table_name [ * ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
    [ LATERAL ] ( select ) [ AS ] alias [ ( column_alias [, ...] ) ]
    with_query_name [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
    [ LATERAL ] function_name ( [ argument [, ...] ] )
                [ WITH ORDINALITY ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
    [ LATERAL ] function_name ( [ argument [, ...] ] ) [ AS ] alias ( column_definition [, ...] )
    [ LATERAL ] function_name ( [ argument [, ...] ] ) AS ( column_definition [, ...] )
    [ LATERAL ] ROWS FROM( function_name ( [ argument [, ...] ] ) [ AS ( column_definition [, ...] ) ] [, ...] )
                [ WITH ORDINALITY ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
    from_item [ NATURAL ] join_type from_item [ ON join_condition | USING ( join_column [, ...] ) ]

and with_query is:

    with_query_name [ ( column_name [, ...] ) ] AS ( select | values | insert | update | delete )

TABLE [ ONLY ] table_name [ * ]

MySQL 5.6

https://dev.mysql.com/doc/refman/5.6/en/select.html

SELECT
    [ALL | DISTINCT | DISTINCTROW ]
      [HIGH_PRIORITY]
      [STRAIGHT_JOIN]
      [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT]
      [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS]
    select_expr [, select_expr ...]
    [FROM table_references
      [PARTITION partition_list]
    [WHERE where_condition]
    [GROUP BY {col_name | expr | position}
      [ASC | DESC], ... [WITH ROLLUP]]
    [HAVING where_condition]
    [ORDER BY {col_name | expr | position}
      [ASC | DESC], ...]
    [LIMIT {[offset,] row_count | row_count OFFSET offset}]
    [PROCEDURE procedure_name(argument_list)]
    [INTO OUTFILE 'file_name'
        [CHARACTER SET charset_name]
        export_options
      | INTO DUMPFILE 'file_name'
      | INTO var_name [, var_name]]
    [FOR UPDATE | LOCK IN SHARE MODE]]

SQL 服务器 2014

https://msdn.microsoft.com/en-us/library/ms189499.aspx

<SELECT statement> ::=  
    [ WITH { [ XMLNAMESPACES ,] [ <common_table_expression> [,...n] ] } ]
    <query_expression> 
    [ ORDER BY { order_by_expression | column_position [ ASC | DESC ] } 
  [ ,...n ] ] 
    [ <FOR Clause>] 
    [ OPTION ( <query_hint> [ ,...n ] ) ] 
<query_expression> ::= 
    { <query_specification> | ( <query_expression> ) } 
    [  { UNION [ ALL ] | EXCEPT | INTERSECT }
        <query_specification> | ( <query_expression> ) [...n ] ] 
<query_specification> ::= 
SELECT [ ALL | DISTINCT ] 
    [TOP ( expression ) [PERCENT] [ WITH TIES ] ] 
    < select_list > 
    [ INTO new_table ] 
    [ FROM { <table_source> } [ ,...n ] ] 
    [ WHERE <search_condition> ] 
    [ <GROUP BY> ] 
    [ HAVING < search_condition > ]

SELECT 后的保留关键字

Reserved keywords after SELECT

mysql

sql

select

keyword

PostgreSQL9.4

MySQL 5.6

SQL 服务器 2014