SELECT - Amazon Timestream

本文為英文版的機器翻譯版本，如內容有任何歧義或不一致之處，概以英文版為準。

SELECT

SELECT 陳述式可用來從一或多個資料表擷取資料。Timestream 的查詢語言支援下列SELECT陳述式語法：

[ WITH with_query [, ...] ]
            SELECT [ ALL | DISTINCT ] select_expr [, ...]
            [ function (expression) OVER (
            [ PARTITION BY partition_expr_list ]
            [ ORDER BY order_list ]
            [ frame_clause ] )
            [ FROM from_item [, ...] ]
            [ WHERE condition ]
            [ GROUP BY [ ALL | DISTINCT ] grouping_element [, ...] ]
            [ HAVING condition]
            [ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ] select ]
            [ ORDER BY order_list ]
            [ LIMIT [ count | ALL ] ]

where

  • function (expression) 是支援的視窗函數之一。

  • partition_expr_list 是：

    expression | column_name [, expr_list ]

  • order_list 是：

    expression | column_name [ ASC | DESC ] 
[ NULLS FIRST | NULLS LAST ]
[, order_list ]

  • frame_clause 是：

    ROWS | RANGE
{ UNBOUNDED PRECEDING | expression PRECEDING | CURRENT ROW } |
{BETWEEN
{ UNBOUNDED PRECEDING | expression { PRECEDING | FOLLOWING } |
CURRENT ROW}
AND
{ UNBOUNDED FOLLOWING | expression { PRECEDING | FOLLOWING } |
CURRENT ROW }}

  • from_item 是下列其中一個：

    table_name [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
from_item join_type from_item [ ON join_condition | USING ( join_column [, ...] ) ]

  • join_type 是下列其中一個：

    [ INNER ] JOIN
LEFT [ OUTER ] JOIN
RIGHT [ OUTER ] JOIN
FULL [ OUTER ] JOIN

  • grouping_element 是下列其中一個：

    ()
expression