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What is the simple operation of database MySQL? in view of this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and easy way.

Take MySQL as an example.

Download, install, mysql and navicat.

Http://blog.csdn.net/bxdxstu/article/details/45746515

2. Knowledge related to database

What is a database will not be introduced. Database is divided into relational database and non-relational database. What we often see are relational databases, such as SQL Server, Mysql, oracle and so on. In view of my lack of talent and learning, I only have more contact with Mysql. So here I will talk about it according to mysql, and then write a good article after I have systematically learned oracle.

2.1 Operation of the database:

2.1.1 Show all databases:

Show databases

2.1.2 create a new database:

Create database database name

2.1.3 Delete the database:

Drop database database name

2.1.4 Select the database you created:

Use database name

2.2 basic operation of the data table:

2.2.1 creation of data tables

Create a table:

CREATE TABLE table name (

Field name 1 Database Type 1 [constraint 1]

Field name 2 Database Type 2 [constraint 2]

Field name 3 Database Type 3 [constraint 3]

Field name 4 Database Type 4 [constraint 4]

...

)

The constraint condition states that PRIMARY KEY identifies the attribute as the primary key, and can uniquely identify the corresponding record NOT NULL that the attribute cannot identify the value of the attribute for empty AUTO_INCREMENT and automatically increase the value of the attribute. UNIQUE identifies that the value of the attribute is the foreign key that uniquely FOREIGN KEY identifies the attribute, and the DEFAULT identification associated with the primary key of a table is the default value set by the data.

Example:

# because I have too many databases here, so select the database first:

Use sys

# create student data sheet

Create table student (

Id int PRIMARY KEY AUTO_INCREMENT

Name varchar (20)

Passwd char (20)

Age int

);

# create a data sheet for student details

Create table stu_detail (

Deid int PRIMARY KEY AUTO_INCREMENT

Birthday DATE

Father varchar (20) NOT NULL

Mother varchar (20) NOT NULL

Sid int

Foreign key (sid) references student (id)

);

Run, and the result is as follows: two tables are created:

2.2.2 View table structure

DESC Datasheet name

SHOW CREATE TABLE Datasheet name

I'll copy it here and see:

Table: student

Create Table:

CREATE TABLE `student` (

`id`int (11) NOT NULL AUTO_INCREMENT

`name` varchar (20) DEFAULT NULL

`passwd` char (20) DEFAULT NULL

`age`int (11) DEFAULT NULL

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8

2.2.3 modify the table name

ALTER TABLE sys_config RENAME sys_conf

2.2.4 modify fields

Change the name and data type of the field:

ALTER TABLE table name CHANGE old field name new field name new data type

Before modification:

After modification:

Add fields:

ALTER TABLE table name ADD field name data type [Integrity constraint] [FIRST | ALTER attribute name 2]

FIRST: where the insert field should be placed.

The results are as follows:

Add a field after / before the specified field:

ALTER TABLE` table name `TABLE` field name `field type AFTER | BEFFORE `field name`

After adding:

Add an index on the specified field:

ALTER TABLE table name ADD PRIMAY KEY (field)

2ALTER TABLE table name ADD UNIQUE (field name); # add unique index

Before execution:

After execution:

2.2.5 deleting a field

ALTER TABLE table name DROP field name

After execution:

2.2.6 Delete field primary key

ALTER TABLE table name DROP PRIMARY KEY

ALTER TABLE table name DROP INDEX index name

2.2.7 Delete table

DROP TABLE table name

After execution, the table no longer exists:

The answer to the question about the simple operation of the database MySQL is shared here. I hope the above content can be of some help to you. If you still have a lot of doubts to be solved, you can follow the industry information channel to learn more about it.

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