what do you usually consider when adding an index? I usually add an index by querying a few fields in the where clause and adding an index to those fields. ...
SELECT A.VA_REGION_NAME AS AREA_NAME, A.VA_CIG_TRADEMARK AS CIG_NM, B.DE_BS_CXB AS CXB_REL, A.DE_BS_CXB_PRE AS CXB_PRE FROM DCDW.FAC_SCC_ZY_REGION_CXB_PRE A LEFT JOIN DCDW.FAC_SCC_ZY_REGION_CXB B ON B.VA_CIG_TRADEMARK = A.VA_CIG_TRADEMARK AND A.VA_RE...
my younger brother has been changing the back-end project recently, but I can t solve it with a bug. I think my back-end knowledge is too lacking, so I ve come here to ask for advice. the process is like this: the front end has uploaded information,...
problem description I want the XH field to increase from 1, because it is of varchar type, so I use this way, but I find that the XH field in my data table starts to increase from 217, why the environmental background of the problems and what method...
use leftJoin multi-table join lookup. Finally, a field in select is a field from count in one of the right tables, but if there is no count data in that table, the entire query will lose the result. Now you want to keep the data in the left table if the...
oracle snooping could have been set up, but suddenly I couldn t connect to the database, so I deleted the original listening file, and then reproduced the installation and found the following problems the hostname also has a correspondence, so sud...
how does Oracle trigger insert or update events after a given time? only once is triggered search on the Internet is triggered repeatedly. How can it be triggered only once? ...
all the lsnrctl instructions have no information. I m not sure whether to start the listener or not. What to do ...
question: select * from table where created_at > where is the problem? How to solve? answer: time writes dead, closes, time opens, there must be closing time. The question is, why should it be a closed interval when querying this time field? It ...
how to restore the database after copying the files in the oradata in the source database? ...
the speed of querying directly on the client is very fast, but the speed in the code is much slower, and the amount of data is about 1 million . this is the query code: List<String> result = new ArrayList<>(); String sql = "SE...
problem description due to the needs of the course, I want to install Oracle12c in Fedora . Now I have completed the preliminary configuration verification. When I run runInstaller , the Oracle installation interface can appear, but there is an er...
The table structure before is like this 2 sql4alias_namealias_name2alias_name3 ...
the requirement is to query the latest 3 transactions of each customer. The sql is similar to the following: select * from ( select , rank() over(partition by order by ) as ranking from ) where ranking > 3 how to use st...
scenario: when the business level deletes (physically deletes) a piece of data from Table A, the data is inserted into Table B. set up a trigger on table A CREATE OR REPLACE TRIGGER cmsinfo AFTER delete ON tablea for each row BEGIN IF DELETING THEN ...
on a recent project, I found that all data types of entity classes are strings, no matter what type of oracle database can be inserted and do not need to be converted. Did the bottom layer of jdbc help me convert it? ...
alter table tn modify CONTENT clob; 1.CONTENT is the keyword 2. Keep reminding me that the ORA-22858 data type change is invalid ...
close also indicates no response, stuck, need to close the process and reopen it? ...
there was a character type problem when using mybatisGenerator to map oracle database tables. the fields represented by number (122.3) in oracle may be converted to bigDecimal , or to Short . In theory, should all be bigDecimal ? oracle (table i...
Environment: Spring3 SpringMvc Hiberate4 SqlServer2005 Oracle11g now it s time to replace the sqlServer database with the oracle database. After changing the database configuration, the project can start normally, but an error will be reported as soo...