SQL - 在雪花中一次查找多个表的记录数

Question

我想看到计数有 1 次表，而不是每个 运行。

对于 EX：

select COUNT(*) from  "Fact_MASTER ";
select COUNT(*) from  "Dim_MASTER ";
select COUNT(*) from  "Fact2 ";
select COUNT(*) from  "Dim2";   
select COUNT(*) from  "Fact3";
select COUNT(*) from  "Dim3"

我们有什么方法可以编写 CTE 来提取临时 table 中每个记录的记录计数，如下所示：

Answer 1

您可以使用 union all:

select 'Fact_MASTER', COUNT(*) from  "Fact_MASTER " union all
select 'Dim_MASTER', COUNT(*) from  "Dim_MASTER " union all
select 'Fact2', COUNT(*) from  "Fact2 " union all
select 'Dim2', COUNT(*) from  "Dim2" union all
select 'Fact3', COUNT(*) from  "Fact3" union all
select 'Dim3', COUNT(*) from  "Dim3"

Answer 2

您似乎希望每个计数都在单独的列中。如果是这样，您可以将每个查询转换为单独的子查询，并且 select 它们：

select 
    (select count(*) from "Fact_MASTER") as fact_master,
    (select count(*) from "Dim_MASTER ") as dim_master,
    (select count(*) from "Fact2")       as fact2,
    (select count(*) from "Dim2")        as dim2,
    (select count(*) from "Fact3")       as fact3
    (select count(*) from "Dim3")        as dim3

Answer 3

你试过吗运行:

SHOW TABLES;

如果您随后想将该信息用于其他用途，您可以进行后续操作，例如：

select "rows" as cnt
from table(result_scan(last_query_id()))
where "name" in (...);

如果您有一组要PIVOT的表格列表，您还可以使用result_scan()函数对数据进行透视：

https://docs.snowflake.com/en/sql-reference/constructs/pivot.html