Common functions: Character functions: Length field character length Concat connection substring Substr intercept Substring Instr Insert substring Remove both ends of trim Upper to upperca
Category: Mysql
MySQL is a relational database management system, developed by the Swedish company MySQL AB, and currently belongs to an Oracle company. MySQL is the most popular relational database management system. In terms of web applications, MySQL is one of the best RDBMS (Relational Database Management System) application software.
Import Excel data for mysql using Navicat Premium
1. Create a data table based on sql.
2. Steps to insert data
3. Error message
1.Data too long for column’ccs_login_name’ at row 1
Modify the character length of ccs_login_na
MySQL main configuration
1.vim /etc/my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=
Why is MySQL assessment (TRUE or TRUE and FALSE) TRUE?
If you enter
SELECT (true or true and false) In mysql, It will return 1, which is true. Why is this happening? What is the order of evaluation in Boolean expressions?
If you enter
Spoon (Kettle) Basic Configuration (Connect MySQL and Oracle)
1. Download the spoon package and driver
The spoon package I use, including spoon7.1, Mysql driver and Oracle driver
link: https:// pan.baidu.com/s/16Q-iUNB7qGU0xlKbGTw-vg Extraction code: q9h5
If you have installed an Oracle database or oracle client locally, you can use its own Oracle driver,
Remember to deal with the experience of the mysql database
One day, the user table in the production environment suddenly locked the table for no reason. I thought it was just an occasional bug. So the first solution that came to my mind was simple and rud
Use node to do the background write interface for Express + MySQL + Node
1. Introduce the corresponding module
const express = require(‘express’)
// Create server express module, express framework coexists with native API , So you can use any native method attrib
Mysql master
1. Installmysql
(1) Unzipmysqlpackage and createmysqlUsers and creationmysqldata directory span>
tar zxvf mysql-5.6.43-linux -glibc2.12-x86_64.tar.gz
mv mysql-5.6.43-linux-glibc2
Mysql – Counting – Optimization of Each Connection
Results:
I have used three methods:
>Three sub-queries, each adding 1 (my)
>Three subqueries, no connection, use where to filter (SlimsGhost)
>Three connections (Solarflare)
I have us
MySQL – How to SUM Time?
I have a table with date and time values in this format:
Start
1/13/2009 7:00:00 AM
End
1/13/2008 2:57:00 PM
I use the’str to date’ function to convert them Date and