above, subqueries, separate execution can query the result set, as the chart



SQL for

So the question to the

IN the face after 29 data query result set, total query result set is empty

But from the query result set inside any a number with=to perform data


Post for the first time, do not know to have described clearly, bosses help explain

CodePudding user response:

SQL can be read very bad,
Sub queries data, a single query data, in theory, the complete bidirectional query should also have data,
So I doubt directly: your son alone query and eventually run the query

CodePudding user response:

Use the exists
And are free of in time attention value, remember NVL processing,

CodePudding user response:

reference 1st floor CEOCAO response:

SQL reading can be very bad,
Sub queries data, a single query data, in theory, the complete bidirectional query should also have data,
So I doubt directly: your son alone query and eventually run the query is not the same as

Diagram shows execution of SQL, in exactly the same subquery, doubt I want to with you, why can alone, combined with its to
not?

CodePudding user response:

Whether the query result set character type fields and inconsistent reason, convert the same type to try?

CodePudding user response:

Do you have this hair - oracle database to view

CodePudding user response:

Don't believe what see, the problem of a single seizure, explain attendance_ilink do have wangxiang1 these data in the table, but you see in the subquery and wangxiang1 you input is not necessarily consistent, suspected in the subquery data encoding, but copy out change, directly if there is a wangxiang1 look at in the query of the subquery data, should not,