Summarize knowledge points in the data

mysql database notes DQL: query statement 1. Sort query 2. Aggregate function 3. Group query 4. Paging query constraint Relationship between multiple tables normal form Backup and restore of database DQL: query statement Sort query Syntax: order by clause order by sort field 1, sort by 1, sort field 2, sort by 2 Sort by: ...

Posted on Fri, 19 Nov 2021 02:39:08 -0500 by thecard

Solutions to errors in ORACLE SELECT INTO syntax ORA-01422 and ORA-01403

background In Oracle functions or stored procedures, the following syntax is usually used to assign values to variables: -- Single variable assignment SELECT [Field 1] INTO [Variable 1] FROM [data sheet] WHERE [query criteria]; -- Multivariable assignment SELECT [Field 1], [Field 2] INTO [Variable 1], [Variable 2] FROM [data sheet] WHERE [qu ...

Posted on Fri, 19 Nov 2021 01:45:29 -0500 by lead2gold

MySQL - triggers and events

trigger We may have the following requirements when using MySQL: Before inserting or updating data into t1 table, the data is automatically verified. The value of m1 column must be between 1 and 10. The verification rules are as follows: If the value of the m1 column of the inserted record is less than 1, press 1 to insert.If the value of ...

Posted on Wed, 17 Nov 2021 21:05:06 -0500 by sneamia

Flask project housing list page, orders, docking Alipay, database optimization

House List Page from . import api from flask import g, current_app, jsonify, request, session from ihome.utils.response_code import RET from ihome.models import Area, House, Facility, HouseImage, User, Order from ihome import db, constants, redis_store from ihome.utils.commons import login_required from ihome.utils.image_storage import ...

Posted on Wed, 17 Nov 2021 12:09:18 -0500 by altergothen

How to obtain the same enterprise level full link gray scale capability in 20 minutes?

Introduction: MSE microservice engine will launch the professional version of service governance, providing out of the box and complete professional microservice governance solutions to help enterprises better realize microservice governance capabilities. If your system can quickly have a complete full link gray-scale capability as described in ...

Posted on Wed, 17 Nov 2021 03:57:10 -0500 by WBSKI

Getting started with python django getting started with models operation

I have 10 years of java development experience and now work in Telecom. I need to learn python and record my learning records. Later, we will continue to share real work experience and projects. Welcome to learn from each other!! Please point out that the article is not rigorous 1. Create a model class Open models.py of the pay application to ...

Posted on Tue, 16 Nov 2021 20:29:33 -0500 by ethan89

Introduction to activiti learning

catalogue Introduce dependency   Create activiti.cfg.xml configuration file (fixed name) Building activit y related data tables         Mode 1:          Mode 2:   Table structure          2 general data sheets (act_ge_) &nbsp ...

Posted on Tue, 16 Nov 2021 19:49:59 -0500 by Adam W

Oracle developer intermediate Lesson 8 (Merge) experiment

summary This experiment refers to the in DevGym Experimental guide. Create environment create table bricks_for_sale ( colour varchar2(10), shape varchar2(10), price number(10, 2), primary key ( colour, shape ) ); create table purchased_bricks ( colour varchar2(10), shape varchar2(10), price number(10, 2), pr ...

Posted on Tue, 16 Nov 2021 11:24:25 -0500 by jstngk

I used Python to make a mailbox bomber to send e-mail to the finance. Unexpectedly, she chased me and shouted six

A project in recent work has the requirement to automatically send some information emails to the specified mailbox, so how to use Python to realize the function of automatically sending emails? Next, let's simply say. Send mail using Python SMTP SMTP (Simple Mail Transfer Protocol) is the simple mail transfer protocol. In other words, it is ...

Posted on Tue, 16 Nov 2021 06:12:21 -0500 by Wildthrust

mysql partition management and maintenance of operation and maintenance tool

mysql partition management and maintenance of operation and maintenance tool The above two blogs briefly introduce what partitions and sub partitions are. This document mainly introduces partition management If you have a large amount of data, it is recommended not to try the operation * *. It should be because a large number of operatio ...

Posted on Tue, 16 Nov 2021 03:54:09 -0500 by saint4