When SQL*Plus performs some select queries, you will encounter some situations where the result is "unselected row". There are many reasons for this. Below I will list what I encountered in practice one by one.
1. Enter select table_name from all_tables where owner='scott'; when querying how many tables there are in a user, pressing the Enter key will report the problem of unselected rows.
The reason is that the case input is incorrect, just change to select table_name from all_tables where owner='SCOTT';.
2. Enter select object_name,object_id from user_objects where instr(object_name,'LOG')>0 in Oracle10g SQL*Plus; when viewing a table with a log character, the prompt of unselected rows is also returned. At this time, it is not that the case of the input characters is incorrect, but that there is indeed no data in the database that meets this filtering criteria. Change it to select count(object_name) from user_objects where instr(object_name,'LOG')>0; when re-querying, you will find that the return result is as follows:
COUNT(OBJECT_NAME)
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0
To be continued, and we also welcome additions to discuss common progress together. . .