PHP MySQL Database

PHP MySQL Database

Classification of databases:

Hierarchical database: Text structure similar to XML (HTML)

Mesh Database:

Relational database:

Mainstream database:

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MySQL is a relational database management system

Sql:struct Query Language structured queries language. is actually an "international" standard

A variety of relational databases, in fact, is to achieve (and expand) the standard of a product

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The nature and performance of database storage:

The essence is that a large number of "data values" through the database management system for some complex but logical structure of the clear and orderly storage

Performance: In fact, the file is stored

Common terminology for relational databases:

Statistics: data;

Databases: Database;

Database management system: DBMS; Database management System

Table (data Sheet): table;

Fields: Field

Columns: Column

Row: Row

Records: Record

Basic structure of the database system:

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MySQL system-level operations and basic syntax rules:

Command line mode: NET Start/stop mysql

Service mode: Control Panel > Administrative Tools > Services > MySQL > Start/stop

Login/Exit Basic operation:

Mysql-hlocalhost-uroot-p;

Mysql-h127.0.0.1-utest-p;

Backup/RESTORE Database:

Backup: mysqldump-h server address-u user name-P database name > file name to store

Recovery: mysql-h server address-u user name-p database name < database name to recover

Basic code and procedures for manipulating databases in PHP:

1: Connect to database: $mylink = mysql_connect ("localhost", ' root ', ' root ');

2: Set the connection code (usually UTF8): mysql_set_charset (' UTF8 '); can also be used: mysql_query ("Set names UTF8");

3: Select the database (if necessary): mysql_select_db ("database name"); Also available: mysql_query ("Use database name");

4: Execute SQL command

$result = mysql_query ("Almost any SQL statement");

The returned results usually need to be handled in two different situations:

If it is a statement with no return data:

If $result is true, indicates successful execution

If $result is false, it indicates that the execution failed

If there is a statement that returns data:

If $result is false, it indicates that the execution failed

Otherwise, the execution succeeds and you need to continue extracting the data from the results and showing it

Supplemental SQL statements:

Set names GBK;

Use DatabaseName;

DESC Table Name: Displays the "Structure information" of a table and returns a result set (similar to a SELECT statement)

Functions to supplement PHP operations:

$record = mysql_fetch_array (result set $result);

Mysql_num_rows ($result); Get the number of rows in the result set

Mysql_num_fields ($result); Get the number of columns in the result set

Mysql_field_name ($result, $i); Gets the name of the I field in the result set (I starts with 0)

mSQL Data Definition Language DDL (language):

Database definition statement:

1: Create the database: creates the [if not exists] databasename [charset character set][collate character collation];

Description

1:if NOT exists is used to determine if the database name exists, and the statement is not executed if it exists

2: Character set: The character encoding name used when the intent data is stored in this database is usually utf8, or it can be GBK

3: Character collations are not usually set, but instead use the default rules for the strings you set (each character set has a default collation);

What is collation: Set the rules for how all the characters in a character set are sequenced

Show all character sets: Show CharSet;

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Show all collations in MySQL: Show collation;

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2: Modify the database, so-called modify the database is to modify the data option value

ALTER DATABASE name character set= new character set collate= new proofing set;

3: Delete Database

drop database name;

Other Database related statements:

Select (Enter) a database: use database name;

Show all databases: show databases;

Displays the creation statement for a database: show create database name;

field type, i.e. data type

Table definition Statements

View definition Statements

Database (table) Design Introduction:

mSQL Data Manipulation language DML (manipulation language)

Insert data:

Delete data:

To modify the data:

PHP MySQL Database