实体类型Entity types

Kusto 查询在某个附加到 Kusto 群集的 Kusto 数据库的上下文中执行。Kusto queries execute in the context of some Kusto database that is attached to a Kusto cluster. 数据库中的数据按表排列,供查询引用。在表中,数据的组织形式是由列和行组成的矩形网格。Data in the database is arranged in tables, which the query may reference, and within the table it is organized as a rectangular grid of columns and rows. 另外,查询可以引用数据库中的存储函数,这些函数是查询片段,可供重复使用。Additionally, queries may reference stored functions in the database, which are query fragments made available for reuse.

  • 群集是用于保存数据库的实体。Clusters are entities that hold databases. 群集没有名称,但可以引用,方法是:将 cluster() 特殊函数与群集的 URI 配合使用。Clusters have no name, but they can be referenced by using the cluster() special function with the cluster's URI. 例如,cluster("https://help.kusto.chinacloudapi.cn") 引用一个保存 Samples 数据库的群集。For example, cluster("https://help.kusto.chinacloudapi.cn") is a reference to a cluster that holds the Samples database.

  • 数据库是命名实体,用于保存表和存储函数。Databases are named entities that hold tables and stored functions. 所有 Kusto 查询都在某个数据库的上下文中运行,而该数据库的实体可以通过没有限定的查询引用。All Kusto queries run in the context of some database, and the entities of that database may be referenced by the query with no qualifications. 另外,可以使用 database() 特殊函数引用群集的其他数据库或者其他群集的数据库。Additionally, other databases of the cluster, or databases or other clusters, may be referenced using the database() special function. 例如: cluster("https://help.kusto.chinacloudapi.cn").database("Samples")For example, cluster("https://help.kusto.chinacloudapi.cn").database("Samples") 是一个通用引用,可以引用特定数据库。is a universal reference to a specific database.

  • 是用于保存数据的命名实体。Tables are named entities that hold data. 表有一组排序的列,有零个或零个以上的数据行,每个行为表的每个列保存一个数据值。A table has an ordered set of columns, and zero or more rows of data, each row holding one data value for each of the columns of the table. 表在引用时,可以只按名称引用(前提是它们位于数据库的查询上下文中),也可以使用数据库引用对其进行限定。Tables may be referenced by name only if they are in the database in context of the query, or by qualifying them with a database reference otherwise. 例如,cluster("https://help.kusto.chinacloudapi.cn").database("Samples").StormEvents 是一个通用引用,引用 Samples 数据库中的特定表。For example, cluster("https://help.kusto.chinacloudapi.cn").database("Samples").StormEvents is a universal reference to a particular table in the Samples database. 也可使用 table() 特殊函数来引用表。Tables may also be referenced by using the table() special function.

  • 是命名实体,有一个标量数据类型Columns are named entities that have a scalar data type. 在查询中引用列时,是相对于表格数据流引用的,该流位于引用列的特定运算符的上下文中。Columns are referenced in the query relative to the tabular data stream that is in context of the specific operator referencing them.

  • 存储函数是命名的实体,方便重用 Kusto 查询或查询部件。Stored functions are named entities that allow reuse of Kusto queries or query parts.

  • 外部表是引用存储在 Kusto 数据库外部的数据的实体。External tables are entities that reference data stored outside Kusto database. 外部表用于将数据从 Kusto 导出到外部存储,还可用于查询外部数据而无需将其引入到 Kusto 中。External tables are used for exporting data from Kusto to external storage as well as for querying external data without ingesting it into Kusto.