one-level subquery can get the result correctly, and multi-layer nested subquery reports an error. Is there any other way to avoid reporting an error select (select id from a where user_id=b.id), b. * from b;-- this can get normal results select (se...
For the items of o2o, the table is as follows: Store shop id name Commodity goods id name cat_id shop_id price Category cat id name search: query the goods that meet the criteria according to the category, list the store, and list the product data. I...
I have a field of type VARCHAR that has a time data stored in it, but I want to compare it with it because I only want to leave the largest time in the same data, because the format of the time data is such a data with spaces. ...
ask SQL SERVERE how to insert a row of data intermittently, that is, a few fields in the first row and then several fields ...
the user guesses the score of a game, which is about < table > < thead > < tr > < th > id < th > < th > team1 (home team scores) < th > < th > team2 (visiting team scores) < th > < tr > < thead > < tbody > < tr > < td > 1 < td > < td > 1 < ...
where exists (select 1 from All_1 t where t.a=All_1.an and t.b > All_1.b) select * from All_1 this compound sentence? How do you solve it? ...
2018-06-08 id select day,itemId,orderNum from test where day = 2018-06-08 8720 20 want such a result ...
How can this be done in one operation instead of two? < H1 >! usr local bin python3 < H1 > import cx_Oracle con = cx_Oracle.connect ( scott tiger@localhost:1512 ORCLPDB1 , encoding= "UTF-8 ") cursor = con.cursor () cursor.execute ( "CREATE ...
DELETE FROM tusers WHERE (code,name) in(SELECT code,name FROM tusers GROUP BY code,name HAVING COUNT(*) > 1) Why can t I write like this? How do you write this? ...
I set the GETDATE default value for the DATATIME data type. As a result, create a new query editor window wants to copy the table. After another name, the excute result shows that couldnt create constraint or index SQL if you don t add this default val...
column name or number of suplied values does not match table defination what do you mean? no matter how you look it up, you can t find out the problem ...
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...
I want to delete the same data only the one with the largest datetime type in the ta field where exists (select 1 from hahha t where t.ta=hahha.ta and t.ta > hahha.ta) select * from hahha previously this condition can delete the value type, but now...
users upload words through the web page, limiting the total number of words uploaded by each user and the space occupied by all words. If the words are not duplicated, how to design a database to save each word uploaded by a user? to ensure that the tota...
in the above table, if you want to find out the number of people in each department, what should you do? ask for divine guidance! the result is like this: number of employees in the department Technical Department 23 Logistics 10 ...
SELECT Table_1. , Table_2. , Table_3.* FROM ((Table_1 INNER JOIN Table_2 ON Table_1.DataTime = Table_2.DataTime) INNER JOIN Table_3 ON Table_2.DataTime = Table_3.DataTime) where Table_1.DataTime = 1 is not necessarily merging three tables with the same ...
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 ...
No place was found. ...
is it feasible to delete and then insert when updating database tables? the contents of the table are many-to-many relationships ...
the structure of the table is as follows: the unread message I am implementing now is: SELECT `n`.`id` FROM `message` AS `m` WHERE `m`.`id` NOT IN ( SELECT `m_s`.`message_id` FROM `message_status`...
as mentioned above, pressing the picture long on the mobile end can display a pop-up window to save the picture. Now there is a need to press a button to trigger the pop-up window on the mobile side to save the picture, and then save the picture. Can thi...
the following is a countdown, but there is no processing, there is a 00 situation, I thought that I could not find the entry point to solve this problem, so it is like asking for advice on how to deal with this. example of 00 situation: for example, ...
recently, a set of APP,APP internal data is shared on a customized machine. If I want to do a set of internal communication between APP processes, I used aidl at first and found that aidl is easy to disconnect in the case of multiple concurrency. And it ...
type UserInfo struct { UserId int `json:"user_id"` Nickname string `json:"nickname"` } func (data UserInfo) A() int{ return 1 } func (data *UserInfo) B() int{ return 2 } ... c.HTML(http.St...
what can be done to transfer the value of 1.vue mobile input to the background 2. After getting this design draft, what do you need to think about vue operation data? 3. Some selected dates require components to implement input. Can they still be loop...