1. If you use select * from APowerB without any conditions, the result will be displayed associated with tables an and b, but the result will be repeated many times 2, and select * from a join b, will not add any query conditions, and the result will b...
is now working on a project, and the requirements are as follows * ppt * * ppt the current technique is to use jacob to manipulate ppt, tables. has been added. < H1 > and now the problem lies in the page added here, and the background image ca...
Table 1: appl_id, name, sex, id_No Table 2: appl_id, appl_date, busin_key in the following time period, find out the nearest time (appl_date) (appl_id) according to (id_No) (duplicate data in Table 1, appl_id is the associated primary key) to_date ...
for example, if you want to query the data after a certain day, you need to make the time field of the timestamp type accurate to the date before judging the query. I don t know what is the common way to deal with this situation. now two solutions ha...
I have several projects that reference dictionaries. The dictionaries of these projects are all cached, and then another project maintains the dictionary, but it cannot access the cached database. It can only put the new or changed data on the oracle, so...
there is a problem. What should I do if I want to take a record that matches multiple characters in a field? select * from actor where last_name like ( % DAVI% , MOSTEL% , ABC , kkk%aa ) the above sql statement is incorrect. Like does not sup...
I want to sort each person s type in descending order according to the sum of the sl of each person s sl. What should I do with ...
1. How to decompose (A, B)-> E, (C, D)-> E, A-> C, C-> An into BCNF,? 2, U = (Agraine Brecinct C pyrrhene E) F = {B-> Greco ce-> Breco C-> Areco B-> Dle le C-> D}. Decompose into BCNF? 3. The BCNF decomposition that I understand at present is to fin...
is like this, and the ultimate effect is to match the avatar address of the drink in the user table for each comment list first, query out the table_1 (article comment table) article comment result set then I found that these comments do not have...
SELECT * FROM `table_1` WHERE `reply_parent` IN (SELECT `reply_id` FROM (SELECT `reply_id` FROM `table_1` WHERE `reply_article`=69 AND `reply_type`=0 LIMIT 0, 5)AS t) UNION (SELECT * FR...
(SELECT * FROM `dozhan_reply` t1 WHERE `reply_parent` IN ( SELECT `reply_id` FROM ( SELECT `reply_id` FROM `dozhan_reply` WHERE `reply_article` = 69 AND `reply_type` = 0 LIMIT 0, 5 ) t )) UNION (SEL...
is there any way? such as recommended books, blogs, etc. ...
problem description : ABAA.id = B.aid B : : ...
after the execution of a SQL statement, it seems that the CPU occupancy of the Oracle database (12c) server has been pulled up, causing all database operations to be slowed down. SQL itself is not special. The logic is as follows: "select sum(a.sh...
normal hadoop execution hadoop what does it mean that multiple map=0%,reduce=0% appear in succession? Last error report: Error while processing statement: FAILED: Execution Error, return code 2 from org.apache.hadoop.hive.ql.exec.mr.MapRedTask ...
using PL SQL Developer to connect to Windows is normal, and the tns configuration is as follows (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.101)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = or...
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problem description orcaleABCAPHONEBPHONECPHONE: A B C ID PHONE ID PHONE ID PHONE a1 11111 b1 11111 c1 11111 a1 22222 b2 33333 c2 11111 now I want to change the PHONE=11111 in ...
Code: stmt, err := db.Prepare("begin TestPro(:1,:2,:3);end;") if err != nil { return "",err } defer stmt.Close() var mail string = "1" var pwd string = "2" var op_re_list string var result sql.Result result,e...
enable limit configuration alter system set resource_limit=true; create a connection number role named sess number of create profile sess limit sessions_per_user; assign to the user alter user username profile sess; when the maximum number of con...