MySQL

ASCII (STR)Returns the ASCII code value of the leftmost character of the string str. If Str is an empty string, returns 0. If STR is NULL, returns NULL. MySQL Tutorial > select ASCII (' 2 '); -> 50 Mysql> Select ASCII (2); -> 50 Mysql>

MySQL tutorial Add new user and modify password method Format: Mysqladmin-u username-P Old password password new password 1, to root add a password ab12. First enter the directory Mysqlbin in DOS, and then type the following command:

Recommendation I: null value does not necessarily occupy space Here I first give you a literacy. Some database tutorial administrators think that null values do not occupy system resources, in fact, this is a mistaken understanding. They do not

MySQL Tutorial common command set Create database name; Create a database tutorial Use DatabaseName; Select Database Drop database name deletes databases directly, without alerting Show tables; Show Table Describe TableName; Detailed

To randomly generate string code as follows: Define a random string method in the MySQL tutorial, and then call this method in the SQL statement. Random string function definition method:Select Round (Round (rand (), 4) *10000);It would be nice

The following query selects all records and its date_col value is within the last 30 days: MySQL Tutorials > select something from tablewhere To_days (now ())-To_days (Date_col) DayOfWeek (date)Returns the week index of date (1= Sunday, 2 =

MySQL Tutorial clear table truncate and delete differences This article demonstrates how to use the truncate command, and the difference between delete and truncateHere's a list of all the data instances that are deleted from a MySQL table.

PHP Tutorial Calling the MySQL tutorial stored procedures methodOn the internet for a long time did not find a good about PHP to invoke the MySQL stored procedure method, I will write a simple about the call to the MySQL stored procedure instance,

If you are in the MySQL tutorial version 5 above, I want to tell you there are three MySQL paging stored process instances Oh, the stored procedure is MySQL 5.0 after the support, now look at this stored procedure, look at a simple stored procedure

Recently, I took over a running project and encountered a problem when pulling it to the local machine for running. When I inserted the database, the error Incorrect integer value: "for column 'id' at row 1 was reported.Literally, the auto-increment

In my opinion, limit should be the most frequently used method in mysql. Next we will explain the role of limit and how to use it correctly.SELECT * FROM table LIMIT [offset,] rows | rows OFFSETThe LIMIT clause can be used to force the SELECT

MySQL is a commonly used RDBMS (RelationalDatabaseManagementSystem/relational database management system), and other relational database management systems such as PostgreSQL, Oracle, and DB2. The importance of database performance does not need to

When the power is down, some innodb tables are broken. phpmyadmin shows that the Table is in use and reports #145-Table '. /shbc/user_order_logs 'is marked as crashed and shoshould be retried red.The myisam table was damaged once in the past. for

FunctionCourse list data displayRequirement1. Normally open classes are displayed on the front, while closed classes are displayed on the back.2. Normal classes start in descending order of course class time3. The completion time of the class is in

When you work on a very large table, you may occasionally need to run many queries to obtain a small subset of a large amount of data, instead of running these queries on the entire table, instead, MySQL can find a few required records each time,

MYSQL should be the most popular WEB backend database. WEB development languages have developed rapidly recently. PHP, Ruby, Python, and Java have their own characteristics? Why do I have to go to the tornado ?? Why? Therefore, zookeeper MYSQL is

Backup bat:@ Set destfile = ICBC_mysql % date :~ 0, 4% % date :~ 5, 2% % date :~ 8, 2%. SQL@ Set ftpfile = ICBC_mysql % date :~ 0, 4% % date :~ 5, 2% % date :~ 8, 22.16.rar@ Echo: date: % date :~ 0, 4% % date :~ 5, 2% % date :~ 8, 2%@ Echo backup

An error is always prompted when importing SQL statements today.The code is as follows:ERROR 2013 (HY000): Lost connection to MySQL server during queryERROR 2006 (HY000): MySQL server has gone awayNo connection. Trying to reconnect...ERROR 2002 (HY00

I have been using Ubuntu for a long time and used to install it online. In centos, use rmp package to install it first, and record the following steps:1. Check and uninstall MySQL installed on the local machineRpm-qa | grep-I mysqlCheck