Programmer Help

First create a students table The SQL script is as follows: create table students( id int primary key auto_increment, age int, name varchar(20), city varchar(20) ) character set utf8; insert into students values(null, 22, 'lisa', 'Hangzhou'); insert into students values(null, 16, 'rock', 'Shanghai'); insert into students values ...

I sorted out some sql statements for beginners, and customized the basic skills necessary for playing mysql database. It is very suitable for beginners to learn! Student list create table student_info ( id int unsigned auto_increment primary key, studentname varchar(10), gender enum('male','female') ); insert in ...

Sometimes, the database table has such a requirement, which requires a record creation time and a record modification time.  The ideal design is that the initial value of the update time is the same as the creation time: CREATE TABLE `test_table` (   `id` INT( 10 ) NOT NULL,   `create_time` TIMESTAMP NOT NULL DEF ...

mysql 5.7 installation This is a series of articles ShardingSphere The first article in this article is about how to build a master for Mysql.The setup environment is centos 7.7 and the database version is 5.7.Three virtual machines are needed, one master and two slaves. Readers can create virtual machines on their own computers, or they can b ...

1. Add delete entity It is very easy to add and delete entities in the secondary development of C ා ObjectARX. The main codes are as follows: Add entity: objId = btr.AppendEntity(entity); trans.AddNewlyCreatedDBObject(entity, true); Delete entity: entity.Erase(true); 2. Basic process In the code YunyouXueYuan namespace, add the Tools class. Thi ...

Note: https://github.com/sunrainwater/oracle-11g.git There is a complete installation code on Clone git code and generate image Direct execution: docker run -it –privileged –name oracle11g -p 1521:1521 -v /data:/install oracle-11g-scripts (no bash will be added to the last side, otherwise it will not be executed au ...

JFinal DB.tx() transaction rollback In order to operate multiple data to the database, transactions are needed. There are encapsulated transaction applications in JFinal Writing: Db.tx(new IAtom(){ 　　@Override 　　public boolean run() throw SQLException{ 　　// Write the operation to be performed and the operation result here result by boole ...

What is multi instance In short, multiple instances of MySQL are to open multiple different server ports on one server at the same time and run multiple MySQL service processes at the same time. These service processes provide services by listening to different service ports on different socket s. Two different mult ...

Using brew to install mysql brew install mysql After the installation is successful, use the following command to start / shut down the service brew services start mysql brew services stop mysql Set up a soft connection for mysql.bin ln -s /usr/local/Cellar/mysql/5.7.21/bin/mysql /usr/bin Enter mysql ...

The basic import and export statements are //Import / export database under specified user and instance orcl impdp/expdp user/pwd@orcl directory=DATA_PUMP_DIR Data ﹣ pump ﹣ dir is the default export path of oracle database files. It is generally the / admin / orcl (instance name) / dpdump directory under the orac ...