Question

I m using Oracle DB and I would like to write a SQL query that I could then call with JDBC. I m not very familiar with SQL so if someone can help me, that could be great ! Here is the problem. I have a table MY_TABLE wich contains a list of another tables, and I would like to keep only the nonempty tables and those that their names start by a particular string. The query I wrote is the following :

 select TABLE_NAME 
 from MY_TABLE 
 where TABLE_NAME like  %myString%  
 and (select count(*) from TABLE_NAME where rownum=1)<>0 
 order by TABLE_NAME;`

问题来自第二次选举考试,但我不知道我如何利用国家选举考试委员会的价值。

是否有人的想法?

感谢。

[补充评论]

实际上,我需要测试“无杀伤人员地雷”表中的五美元观点。但是,如果我能找到另一个桌子,把所有这些观点也列入其中,并用一个NUM。 ROWS一栏也是完美的!

Answer 1

标准版本不允许你以可变数值或地籍持有人取代盘点的结构要素,如表格名称或栏目。

这样做有几个途径。

Generate a separate SQL statement for each table name listed in MY_TABLE, and execute each in turn. Brute force, but effective.
Interrogate the system catalog directly.
Investigate whether there are JDBC metadata operations that allow you to find out about the number of rows in a table without being tied to the system catalog of the specific DBMS you are using.

Answer 2

您能使用或认为可以使用 TABLES? 那么,问询会更加容易

select TABLE_NAME 
from USER_TABLES 
where TABLE_NAME like  %myString%  
and Num_ROWS > 0
order by TABLE_NAME;`

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