First, user management:1. New User:
>create USER name identified by ' Ssapdrow ';
2. Change Password:
>set PASSWORD for Name=password (' FDDDFD ');
3. Rights Management
>show GRANTS for name; View name User Rights
>
-- Create a data table --[Use the database name to create the data tableGoCreate table name to be created(Field name data type [length] [null | NOT NULL] [primary key],... ... ... ... ,Field name data type [length] [null | NOT NULL]) go create
Overview
1. Database
A> Create a database
-- Determine whether the database exists and delete the database:
Use master
GoIf exists (select * From sysdatabases where name = 'Teach ')Drop database teach
Go
Note: The
ALTER table-sql Command
Modify the structure of the table programmatically.Grammar
ALTER TABLE TableName1ADD | ALTER [COLUMN] FieldName1FieldType [(Nfieldwidth [, Nprecision])][NULL | Not NULL][CHECK LExpression1 [ERROR CMessageText1]][DEFAULT
I. SQL statement syntax 1.ALTER TABLEALTER table is used to update the structure of existing tables.ALTER TABLE TableName (ADD| DROP column DataType [null| Not NULL] [CONSTRAINTS]2.COMMITCOMMIT is used to write things to the
Description : The following words may have multiple meanings , This document is intended to be interpreted only for programming . words are not much, practice makes perfect, read and write every day, the effect is good. If there are errors , Please
ObjectiveMYSQL/MARIADB is an open-source small-scale relational database management system, because of its small size, speed, low total cost of ownership, especially the open source, many small and medium-sized web sites in order to reduce the total
[Android] [Memory Leak] Inputmethodmanager memory leak phenomenon and its solutionphenomena : on the k_touch_v9 model of a particular model , an interface appears Inputmethodmanager hold a Activity, causes the Activity cannot be recycled . if the
Overview
In general, once the database structure has been designed, it cannot be easily changed because changes DDL (Data Definition Language) are expensive to operate, so you need to be cautious about database structure design.
However, business
Database and table, column operation, common function one, the establishment of databaseFormat: CREATE database "file name" Modify Database Format: ALTER database "file name" {} Deleting a database DROP database "file name"Ii. establishing the
Build a Table statementCREATE TABLE table_name(column_name DATATYPE [null| Not NULL],column_name DATATYPE [null| Not NULL],...[CONSTRAINT]);Example:CREATE Tabletest(ID VARCHAR () not NULL,T_date DATE not NULL,T_number number not NULL note at the end
Oracle Check Constraints
Oracle | PL/SQL Check constraints usage1. The target instance explains how to use the CHECK constraint (create, enable, disable, and delete) in Oracle. 2. What is the Check constraint? The CHECK constraint adds additional
MySQL page normal database file SQL garbled if your database is originally gbk encoding, save the following code as a PHP file, remember to fill in the following database name and database account password
MySQL page normal database file SQL garbled
Recently, considering the usage of temporary tables in the database write stored procedures
It is still unclear how the database is processed, whether it is consistent with the SQL server processing method.
Are there any problems, such as
Chapter 2 Introduction to database concepts and SQL
A relational database is a data structure in the two-dimensional table format. It is accessed Based on associations between data tables.
I. Basic concepts of databases
1. database structure:
The
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