Embedding query operations in MySQL IF statements

Is there a way to run insert query in IF statement, I know the syntax of if statement is IF (condition, statement to be executed if condition is true, statement to be executed if condition is false) My question is if it is possible to run insert statement based on condition, For example IF((select c...

P粉155832941 2024-02-17 16:44:15 0  1  480

javascript - Asking for help with a question about indexedDB

As shown below, the primary key of a piece of data I stored is timeStamp. What I know is that I can find this data by getting the primary key value, but can't I retrieve the data by querying other values ​​in it? Can query conditions similar to SQL statements not be implemented? (Find them all and t...

某草草 2017-06-05 11:13:09 0  2  684

php - Is there any performance problem if the sql statement is written like this? ? How to improve? ?

Multi-table joint query + subquery + conditional query + sorting {code...} Related data tables: csp_car_brand, vehicle brand table: csp_car_type, vehicle type table: csp_car_source, vehicle source table: csp_car_model, vehicle model table (specific to the brand model): ...

高洛峰 2017-05-24 11:30:34 0  1  607

mongodb的java开发中使用两个字段相等查询条件应该怎么写？

也就是类似sql中的where 字段A=字段B这样的条件，我查了下网上有些帖子中写的用$where的方式我查询的时候会出错，类似于：new Document("$where",new Document("字段A", "字段B"))，请教应该怎么写才对？

黄舟 2017-04-28 09:06:01 0  1  610

javascript - mongoose sorting of query results

The set of collections I now get through mongoose query looks like this: {code...} I hope to sort it like this: {code...} That is, under the condition of sex ascending order, _id will then ascend. I currently set it when querying in mongoose: {code...} This becomes an array of _id in ascending order...

滿天的星座 2017-05-02 09:26:10 0  1  795

mongodb 文档数组查询的一个问题

1对多群发消息，文档结构如下： { "from_uid" : 10000, "to_uid" : [ {代码...} ]} 其中to_uid.user_id=100002,设置为is_del=1。执行以下指令的时候，这个文档还会显示。 貌似查询条件里的"to_uid.user_id" "to_u...

滿天的星座 2017-04-27 09:02:45 0  2  810

laravel - laravle Eloquent ORM updates multiple records at one time

Eloquent updates multiple records in batches. Instead of assigning values ​​to multiple fields in one record in batches, it makes different modifications to different records based on different conditions. Similar to batch insertion: {code...} Is there any similar statement {code...}? The function i...

phpcn_u1582 2017-05-16 16:54:58 0  1  580

java - Should newbies use springmvc directly or springboot?

Convert PHP to Java, have a basic understanding of the Java language, have done some Android research using Java, and roughly understand that springboot is similar to a packaged thing. I heard that newcomers have trouble solving problems when using it. Springmvc needs to combine and install componen...

伊谢尔伦 2017-05-17 10:04:37 0  5  668

SELECTING with multiple WHERE conditions on the same column

Okay, I think I might be overlooking something obvious/simple here... but I need to write a query that only returns records that match multiple criteria on the same column... My table is a very simple Link settings for applying flags to users...IDcontactidflagflag_type-------------------------------...

P粉384366923 2023-08-23 19:08:16 0  2  445

Why doesn't the URL constructor encode parentheses in the query string?

In JavaScript, the URL constructor does not encode brackets and parentheses when they appear in a query string, whereas encodeURI or encodeURIComponent always encodes them. This confuses me because most sources say to use encodeURI/encodeURIComponent for encoding when you include special characters ...

P粉287254588 2023-09-03 21:05:00 0  1  467

php - Some questions about adding index to mysql database

I have some questions about mysql indexes. I have consulted a lot of information, but the information is very vague. There are several types of indexes that I don’t know how to add: 1. How to add groupby indexes? Add an index alone or add it together with search conditions? 2. How to add a query ind...

学习ing 2017-06-30 09:53:12 0  4  922

How to use RTK queries with selectors

I'm building a project using ReduxToolkit and RTK queries and trying to get some entries from the API. I'm using the normalize data method of createEntityAdapter because in a certain component I need the data as an array, so I ended up using a selector. Now my problem is that since I added the filte...

P粉729198207 2023-12-28 11:46:38 0  1  684

PHP method to get query parameters sent to script

A friend contracted with some WordPress agency to create a web page that creates a custom URL based on the input data the user enters on a form to redirect to a 3rd party API that displays some car rental data, this WordPress plugin is done using elementor , the problem is, when the redirect query p...

P粉459578805 2024-03-29 13:45:30 0  1  416

Ways to fix issue 2003 (HY000): Unable to connect to MySQL server 'db_mysql:3306' (111)

I recently tried to containerize my FastAPIPython server (also for replication/doubling purposes). Before, I had just a MySQL server in a Docker container and everything was fine, but when I also made my web server a service, it couldn't connect to the MySQL server, so now the application doesn't wo...

P粉178132828 2023-09-05 11:18:47 0  1  773

Experiment with sorting after query limit

So this is my first question here, please forgive me if something is wrong. I'm trying to make a sort query based on constraints. So there is a Customers table with 90 records. I want to first perform a query limited to 3 records, and then sort the results of this query by a column called ContactNam...

P粉237125700 2023-09-05 14:46:42 0  1  703

CSS Grid: Create new row when child content overflows column width

I have a two column layout based on CSS grid. When the content of the second column exceeds 1fr I want to create a new row. As it currently stands, the content simply overflows the column. One requirement of this layout is that the items in the right menu column are in one row. I achieve this with: ...

P粉212114661 2023-09-05 15:18:28 0  1  594

PHP full text search functionality using AND, OR and NOT operators

Newbie question: I'm trying to implement a full text search on a search string using php and eloquent. $searchstring="+(victimsuspect)+crime-covid";$searchresult=RssItem::whereRaw("MATCH(description)AGAINST('$searchstring'INBOOLEANMODE)")->ge

P粉076987386 2023-09-05 15:06:32 0  1  552

Shortest way to convert all PHP types to string

I'm writing a general system that I hope can one day be applied to fields like medicine (i.e. it's "scientific"). I think the best way is to represent all the data in php with strings (true will be "true", false will be "false" and so on). The reason for this is that in...

P粉369196603 2023-09-05 15:34:44 0  1  981

How to get average of DATETIME column in MySQL while grouping by other columns

I'm creating and populating a MySQL table using the following query: SETtime_zone='+00:00';CREATETABLEtimestamp_n_datetime(idINT,timeDATETIME,avg_timeDATETIME);INSERTINTOtimestamp_n_datetime(id,time,avg_time)VALUES("1","2023-01-0310:

P粉460377540 2023-09-05 11:46:21 0  1  495

Multi-device (mobile phone) synchronization - React Native

I'm trying to create a Lightshow that will launch on all users' mobile devices at the same time (can have up to 2000-3000 users). All users will use the Internet (Wi-Fi or mobile data). In our FE we use Apollo for subscriptions and it works like a charm. But the problem is, user A can get subscribed...

P粉151466081 2023-09-05 11:58:38 0  1  684