In mysql, the time type is datetime , orm is sequelize , how to get the data within 7 days and 30 days in the table, how to write the query conditions (is it where date_col > 7 days ago datetime), and whether sequelize provides a more convenient way...
b-tree structure if the name field is an index, then if there are seven pieces of data in the table, all nodes in the b-tree also have seven pieces of data, so isn t scanning the entire data area as efficient as scanning the entire index area? ...
[RowDataPacket {name: zhang3 , password: undefined , random: null}, RowDataPacket {name: zhang3 , password: undefined , random: null}, RowDataPacket {name: zhang3 , password: undefined , random: null}, RowDataPacket {name: zhang3 ...
$ymdh = date( Y m d H ); $findOrderSoFar = mysqli_fetch_array($pdo->query( "SELECT count(public_order_id) as num FROM `order_record` WHERE FROM_UNIXTIME(add_time, %Y %m %d %H ) = {$ymdh} " )); $i $i = $findOrd...
for example, 10 pieces of data I took out of the database and paged into two pages to upset the order is 10 pieces of data to be disrupted and then paged how to deal with it? Tp framework ...
how does 1.mysql export a data table of 6 million records? 2. I ve tried that direct export will overload the database. ...
how does mysql export a data table from the beginning to the end of a field? ...
discuss a few questions, thank you! 1 the working principle of aof storage is used by Magi Redis? 2 how does aof rewrite work? In which processes the main thread and the generated new thread play a role respectively. ...
the database to the right of idea cannot connect to the mysql service in the virtual machine the same step is used to install a mysql service on the cloud server, but the connection to the virtual machine will fail, and it should not be a problem with...
func DBGetAdd(t string, n string, v string) map[string]string { sql := "insert into "+t+"("+n+") values("+v+")" ret, err := DB.Exec(sql); d := map[string]string{} if err != nil { ...
docker for windows uses windows container to start mysql:latest error and switch to linux container to start normally. start command: docker run-- name mysql_01-e MYSQL_ROOT_PASSWORD=root-d mysql docker log: ...
the following code implements tagging the data. After a carPlate appears (set to 2 for the first time), the mark is invalid within 1 hour (set to 1), the first one for more than 1 hour is set to 2, and so on. the main problem is that I have several ta...
in wordpress, the attachment is saved in the same table as the article, but all the information in the attachment is saved according to the following format. Why this format? by the way, how did this format come from? a:5:{s:5:"width";i:800...
recently, I am working on a book information management system. There is a table marc that stores the information of books. There are more than 20 fields in it. when importing data, it is required to check the duplicates according to 7 fields, and the...
with regard to mysql transaction rollback, how to roll back if multiple statements are involved? for example: sql ...
Connect to the database in the framework automatically generated by express connect.js Code const mysql = require( mysql ); const db = mysql.createConnection({ host: localhost , port: 3306, user: root , database: ningxia }) d...
the company has two Wifi that are both telecom, and the online server has access to port 3306. when making a connection, it will connect for a long time, and then timeout or return an error. prompt ERROR 2026 (HY000): SSL connection error: error:00...
SELECT DATE_FORMAT("2019-01-01", "%x%v") AS currentWeek; % v the week begins on Monday, and the following results are obtained: 20160101 (5)-> 201553 20170101 (Sun)-> 201652 20180101 (1)-> 201801 20181231 (1)-> 201901 20190...
would you like to ask if mysql supports it? Placeholder ...
there is a need for to find the same current week as mysql for other purposes SELECT DATE_FORMAT(NOW(), "%v") - 1 AS currentWeek this is written by another person. I m thinking about implementing this requirement in code. What I m worrie...
I don t understand why this is window in this broken code. Thank you for your understanding. Thank you. var o = { fn:() => { console.log(this) } } o.fn() ...
Both then and catch in promise can handle exceptions, so what s the difference between them in handling exceptions? Promise.reject( error ).then(()=> {}, val=> { console.log(val); }); Promise.reject( error ).catch(val=> { console...
due to the needs of the project, the front-end js cannot cross domains, so I use nginx to reverse proxy. Since I am testing locally, I am a windows system. Nginx listens to 8010. Apache listens to 8080. Local hosts 127.0.0.1 mychain.com nginx is con...
HTTP ERROR 500 is reported after our website is upgraded to php7, but I turn on the error message output and there is no error message output. Here is my error message output code set_error_handler ( "_ errorHandler "); set_exception_handler ( "_ exc...
I installed carbon, with composer and got an error when using it: fatal error: Class CarbonCarbon not found I installed it using composer require nesbot carbon. The directory structure after installation is as follows: Do you want to set some...