Question

我有一个数据库并且有2个模式叫DWFR和DWFR3，我需要做的是比较2 schmea并获取匹配的表名以及DWFR模式中存在的表，这在DWFR3上是不可用的以及下面的条件

SELECT schema_name, table_name 
FROM tables 
WHERE schema_name = 'DWFR' 
    AND table_name NOT LIKE 'RA%' 
    AND table_name NOT LIKE 'ZZ%' 
    AND table_name NOT LIKE 'DELETE%' 
    AND table_name NOT LIKE '%TEST%' 
    AND table_name NOT LIKE 'XX%' 
    AND table_name NOT LIKE 'ROB%' 
    AND table_name IN (
            SELECT table_name 
            FROM tables 
            WHERE schema_name = 'DWFR3' 
                AND table_name NOT LIKE 'RA%'
                AND table_name NOT LIKE 'ZZ%'
                AND table_name NOT LIKE 'DELETE%' 
                AND table_name NOT LIKE '%TEST%' 
                AND table_name NOT LIKE 'XX%'
                AND table_name NOT LIKE 'ROB%'
        )
ORDER BY schema_name, table_name;

这将获得匹配的表名，但我也希望DWFR中的表名不是DWFR3上的表。

Answer 1

您可以使用LEFT OUTER JOIN从一组中选择所有数据行，从第二组中选择匹配。

我在脚本中使用了SQL CTE公用表表达式，您可以将其视为具有其他用途的子选择

以下是您可以如何使用案例

with t2 as (
    select table_name
    from tables
    where schema_name = 'DWFR3'
)
select t1.table_name, t2.table_name
from tables t1
left outer join t2
    on t1.table_name = t2.table_name
where t1.schema_name = 'DWFR'

您还需要将附加要求或WHERE子句附加到上面的脚本

中

我使用CTE的原因可以解释如下。实际上，实际的解决方案应该如下所示。遗憾的是，HANA似乎不支持使用JOIN上的ON子句的其他过滤条件

select t1.table_name, t2.table_name
from tables t1
left outer join tables t2
    on t1.table_name = t2.table_name and t2.schema_name = 'DWFR3
where t1.schema_name = 'DWFR'

由于这个原因，我必须比应用ON，join条件更早地过滤JOIN的LEFT部分

Answer 2

在两个模式中查找匹配的表名：

select
    'DWFR' as schema_name,
    table_name
from
    (
        select table_name from tables where schema_name = 'DWFR'
        intersect
        select table_name from tables where schema_name = 'DWFR3'
    ) x
where
    table_name not like 'RA%' and
    table_name not like 'ZZ%' and
    table_name not like 'DELETE%' and
    table_name not like '%TEST%' and
    table_name not like 'XX%' and
    table_name not like 'ROB%';

在DWFR中查找表名但不在DWFR3中查找：

select
    'DWFR' as schema_name,
    table_name
from
    (
        select table_name from tables where schema_name = 'DWFR'
        except
        select table_name from tables where schema_name = 'DWFR3'
    ) x
where
    table_name not like 'RA%' and
    table_name not like 'ZZ%' and
    table_name not like 'DELETE%' and
    table_name not like '%TEST%' and
    table_name not like 'XX%' and
    table_name not like 'ROB%';

SQL查询在sap hana中

2 个答案: