as 运算符as operator
将名称绑定到运算符的输入表格表达式,从而允许查询多次引用表格表达式的值,而不会中断查询,并通过 let 语句绑定名称。Binds a name to the operator's input tabular expression, thus allowing the query to reference the value of the tabular expression multiple times without breaking the query and binding a name through the let statement.
语法Syntax
T |
as
[hint.materialized
=
true
] NameT |
as
[hint.materialized
=
true
] Name
参数Arguments
- T :表格表达式。T : A tabular expression.
- 名称 :表格表达式的临时名称。Name : A temporary name for the tabular expression.
hint.materialized
:如果设置为true
,则表格表达式的值将被具体化,就像它已由 materialize() 函数调用包装了一样。hint.materialized
: If set totrue
, the value of the tabular expression will be materialized as if it was wrapped by a materialize() function call.
备注
as
提供的名称将用于 union 的withsource=
列、find 的source_
列和 search 的$table
列。The name given byas
will be used in thewithsource=
column of union, thesource_
column of find, and the$table
column of search.- 在 join 的外部表格输入 (
$left
) 中使用运算符命名的表格表达式也可用于 join 的表格内部输入 ($right
)。The tabular expression named using the operator in a join's outer tabular input ($left
) can also be used in the join's tabular inner input ($right
).
示例Examples
// 1. In the following 2 example the union's generated TableName column will consist of 'T1' and 'T2'
range x from 1 to 10 step 1
| as T1
| union withsource=TableName T2
union withsource=TableName (range x from 1 to 10 step 1 | as T1), T2
// 2. In the following example, the 'left side' of the join will be:
// MyLogTable filtered by type == "Event" and Name == "Start"
// and the 'right side' of the join will be:
// MyLogTable filtered by type == "Event" and Name == "Stop"
MyLogTable
| where type == "Event"
| as T
| where Name == "Start"
| join (
T
| where Name == "Stop"
) on ActivityId