Question

我想在我的架构hr中找到空表的数量，并且我已经为它编写了代码：

set serveroutput on;


Declare
d Number;
c varchar2(25);
cursor c1 is SELECT DISTINCT OWNER, OBJECT_NAME FROM DBA_OBJECTS WHERE OBJECT_TYPE = 'TABLE' AND OWNER = 'HR';

Begin
 for r in c1
Loop
select count(*) into d
from (r.object_name);
if (d = 0) then
dbms_output.put_line(r.object_name||'is Empty');
end if;
end loop;
end;

但它在（r.object_name）的这一行抛出错误。任何人都可以帮助我吗？

Answer 1

查询dba_tables.num_rows不可靠，因为这是估算值。如果从未对表进行过分析，则可能无法反映正确的行数。

此处也不需要动态SQL。基于计算所有表的行数的my answer，您只需添加where条件：

select table_name
from (
  select table_name, 
         to_number(extractvalue(xmltype(dbms_xmlgen.getxml('select count(*) c from '||owner||'.'||table_name)),'/ROWSET/ROW/C')) as row_count
   from all_tables
   where owner = 'HR'
)
where row_count = 0;

Answer 2

您需要dynamic SQL（execute immediate）：

declare
  d number;
  v_sql varchar2(1000);

  cursor c1 is select object_name 
    from all_objects 
    where object_type = 'TABLE' and owner = 'HR';

begin
  for r in c1 loop
      v_sql := 'select count(*) from HR.'||r.object_name;
      execute immediate v_sql into d;
      if d = 0 then
          dbms_output.put_line(r.object_name||' is empty');
      end if;
  end loop;
end;

Answer 3

在Oracle中，您可以使用以下查询。

select    count(*) from    dba_tables  where    OWNER = 'XXXX' and num_rows =0;

查询以查找模式名称HR中的空表数

3 个答案: