engine innodb

Internal connection Query Meaning: Find the relationship between a table and a table or a bridge. The connection query is used when querying two or more than two tables. join| Cross join| INNER join via on join condition (all three ways)

before MySQL 5.6.6, the default behavior of timestamp is: The timestamp column defaults to not nullif the NULL property is not explicitly declared. (While other data types, null values are allowed if no display is declared as NOT null.)

BackgroundThe Start_time,end_time time field in the previous Business feedback table was automatically updated over time, which is not the business will, and the serious point is that it is going to fail.There are date,datetime,timestamp time types

Transferred from: http://blog.csdn.net/wyzxg/article/details/7700394MySQL official website configuration description Address: http://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.htmlOther references:"High performance MySQL"-8.4.5 innodb buffer

This is to distinguish between the easily confusing concept of lock and latch. In the database, lock and latch can be locks, but they have different meanings.Latch is generally called a latch (lightweight lock) because it requires a very short time

1. Background of the problem(1) Student form (school number, name, age, gender)Student (S#,sname,sage,ssex)(2) Course Schedule (course number, course name, teacher number)Course (c#,cname,t#)(3) Score table (School number, course number,

1. The following is a table statement that is exported directly from the database.1-- ----------------------------2--Table structure forFiles3-- ----------------------------4 DROP TABLE IF EXISTS ' files ';5 CREATE TABLE ' files ' (6' ID 'int(11)

First, maintain the partitionFor the maintenance of the table, we generally have the following methods: CHECK table, OPTIMIZE table, ANALYZE table and Repair table.In these ways, the same applies to partitions. Below, we explain the various roles.1.

Insert into products (Prod_id,prod_name,pro_price) VALUES (' Avno1 ', '. 5 ton Anvil ', 5.99);Insert into products (Prod_id,prod_name,pro_price) VALUES (' Avno2 ', ' 1 Ton Anvil ', 9.99);Insert into products (Prod_id,prod_name,pro_price) VALUES ('

Suddenly received an alarm SMS, prompted that there is a group of servers MHA has been switched, log on to the server after the error log (where the relevant INSERT statement has been processed):MySQL version: 5.5.24151221 -: Wu: -Innodb:assertion

MySQL replace into and on duplicate key update test notesMysql> CREATE TABLE tbl_insert_tmp (ID int (5), Addr_number Int (ten), name varchar, primary key (ID), unique key Udx_add R_number (Addr_number));Query OK, 0 rows affected (0.05 sec)Mysql>

A new framework was built, using spring boot replacements to simplify the original cumbersome spring configuration, using spring annotations to manage transactions, and persistent layers using MyBatis.Connection to MySQL database The process of

/* MySQL Data Transfer Source host:localhost Source Database:book Target host:localhost Target Database:book date:2008-7-25 13:55:48 */ SET foreign_key_checks=0; -- ---------------------------- --Table structure for T_book -- --------------

With the company's business needs, it took two weeks to implement a small payment system, though small spite, all kinds of necessary modules such as account lock, transactional assurance, running water reconciliation are fully realized, the whole

Today continue to see the teacher to recommend the simple and simple MySQL database development This book, see INNODB Database Foreign Key Association problem, encountered a problem, the book is written on the parent table can be modified to sync to

Previous articles covered the Spring cloud SSO integration scenario, the Spring + JWT + Redis solution, the seamless integration of different systems, the unified SSO single Sign-on interface management, the authorization for each application

FOREIGN KEY constraint exception phenomenonIn the following example, there is no insertion failure that violates the referential constraint.create database `a-b`;use `a-b`;SET FOREIGN_KEY_CHECKS=0;create table t1(c1 int primary key, c2 int)

Background:Self-growth is a very common data attribute, and in MySQL everyone is willing to let the field of the self-growth attribute be a primary key. In particular InnoDB, because of the characteristics of the InnoDB clustered index, using fields

Concept: A table consisting of one or more physical partitionsType: RANGE HASH LIST KEYThe following main implementation range and hashA. Range type partition Table 1. By primary KEY partitioningDROP TABLE IF EXISTSP_user;CREATE TABLEP_user

In routine maintenance, the threads are often blocked, causing the database to respond very slowly, and see how to obtain which thread is causing the blocking.Blog Address:http://blog.csdn.net/hw_libo/article/details/390808091. Environment