Categories:: Data metric functions

BLANK_PERCENT（系统数据指标函数）¶

返回表中指定列的空列值的百分比。

This topic provides the syntax for calling the function directly. To learn how to associate the function with a table or view so it runs at regular intervals, see Associate a DMF.

语法

SNOWFLAKE.CORE.BLANK_PERCENT(<query>)

实参

query: 指定一个 SQL 查询，该查询仅投射单个列。

允许的数据类型

The column projected by the query must have the VARCHAR data type.

该函数会返回 NUMBER 值。

示例

测量 SSN 列的空白字段的百分比（US 社会保障号）：

SELECT SNOWFLAKE.CORE.BLANK_PERCENT(
  SELECT
    ssn
  FROM hr.tables.empl_info
);

+-------------------------------------------------------------------+
| SNOWFLAKE.CORE.BLANK_PERCENT(SELECT ssn FROM hr.tables.empl_info) |
+-------------------------------------------------------------------+
| 1                                                                 |
+-------------------------------------------------------------------+