5.MySQL database Operation steps

First step: Log in to MySQL Server

Step two: Select the database you want to work with now

Step three: Set the character set of the request and return data

Fourth Step: Execute SQL Statements

L Add record: INSERT into News (title,content) VALUES (' title ', ' content ')

L Delete Record: Delete from news WHERE id=180

L Modify Record: UPDATE news SET title = ' new title ', content = ' new content ' WHERE id=180

L Query record: SELECT id,title,hits from News WHERE id<100 ORDER by id desc LIMIT 10,10

To Import test Data saixinjituan.sql steps

steps for php+mysql database programming

L First step:PHP connection to MySQL Server

L Second Step: Select the database you want to work with now

L Step Three: Set the character set of the requested or returned data

L Fourth Step: Execute various SQL statements.

PHP Connection to MySQL server

1,mysql_connect ()

L Description:PHP connects to MySQL server.

L Syntax:resource $link = mysql_connect ($hostname, $username, $password)

L Parameters:

U $hostname: is the domain name or IP address of the MySQL server . You can also add a port number (3306). such as:localhost:3306

U $username: is The user name of the MySQL server. such as:root

U $password: is the MySQL Server user password. such as:root

L return value: Returns a resource identifier if execution succeeds. Returns FALSE if the execution fails .

2.exit ()

L Description: Output a message and abort the script to continue running down.

L Syntax:void exit ([$msg])

L parameter:$msg is optional. If omitted, only the script run is aborted.

L Example: Exit (" error in PHP connection ")

3,mysql_error ()

L Description: Returns the text error message of the last MySQL execution Failure .

L Syntax:mysql_error ()

4, shielding system error @

Description:@ can mask various function call errors, or contain file errors, but cannot be used before function definitions or class definitions.

Select MySQL database

mysql_select_db ()

L Description: Select the database that you want to manipulate now

L Syntax: bool mysql_select_db (String $database _name [, Resource $link])

L Parameters:

U $database _name: Specifies the name of the database to select.

U $link: Optional. Specifies the current active connection. If omitted, the active connection is open on the previous one.

L return value: Returns TRUE if the database selected is successful . Returns FALSE if the database selection fails .

Set The data character set returned by MySQL

mysql_query ("set names UTF8")

Description: To The MySQL server sends a request or returns the data character set of the request result.

mysql_query ()

L Description: Send a MySQL query.

L Syntax:resource mysql_query (string $query [, Resource $link = NULL])

L Parameters:

U $query: refers to the SQL statement to be sent .

N Add Record: $query = "INSERT into News (title,content) VALUES (' title ', ' content ')"

N Delete Record: $query = "Delete from news WHERE id=10"

N Modify Record: $query = "UPDATE News SET title = ' new title ', content = ' new ' where id=80 '

N Query record: $query = "SELECT * FROM news WHERE id<100"

U $link: Optional. Refers to the last active connection that was opened.

L return value

If you execute the Select,SHOW,DESCRIBE command, the result set is returned on success and FALSE on failure .

The U result set is also a resource identifier, which is a reference address to MySQL data.

If you execute a different SQL statement, the execution returns TRUEsuccessfully, and the execution failure returns FALSE.

L Example:

U $result = mysql_query ("SELECT * FROM News WHERE id<100")

U $result = mysql_query ("DELETE from News WHERE id=100")

To fetch a row of data from the result set

1,mysql_fetch_row ()

N Description: Gets a row from the result set as an enumeration array.

n Syntax:array mysql_fetch_row (resource $result)

n parameter:$result is a result set variable.

n return value: Returns an enumerated array, which is a positive integer subscript starting at 0. The subscript here is corresponding to the table's field subscript.

n Example: $arr = Mysql_fetch_row ($result)

2,mysql_fetch_array ()

U description: Takes a row out of the result set and returns as a mixed array.

U syntax:array mysql_fetch_array (resource $result [, int $ result_type])

U parameter:

U $result: refers to the result set variable.

U $result _type: Refers to the type of the returned array. Value:mysql_both,mysql_assoc,mysql_num

N mysql_both: Default. That is, both subscripts exist.

N MYSQL_ASSOC: An array of only character subscripts. Equivalent to the function of MYSQL_FETCH_ASSOC ().

N mysql_num: An array of only integer subscripts. Equivalent to the function of mysql_fetch_row ().

n more than three parameters are constants, system constants must be all uppercase.

U return value: Returns an array, as to what array, depending on the second argument.

u Example:

U $arr = mysql_fetch_array ($result)// mixed array

U $arr = mysql_fetch_array ($result, MYSQL_ASSOC)// associative array

U $arr = mysql_fetch_array ($result, Mysql_num)// Enumeration Array

3,mysql_fetch_assoc ()

U description: Takes a row from the result set and returns it as an associative array.

U syntax:array mysql_fetch_assoc (resource $result)

u example: $arr = Mysql_fetch_assoc ($result)

PHP function Supplement

1.include syntax structure

L Description: Contains and runs the specified file.

L Syntax: include $filename or include ($filename)

L Example: include "include/conn.php"

PHP function Supplement

1.include syntax structure

L Description: Contains and runs the specified file.

L Syntax: include $filename or include ($filename)

L Example: include "include/conn.php"

2.require grammatical structure

L Description: Contains and runs the specified file.

L Syntax: Require $filename or require ($filename)

L Example:require "include/conn.php"

Note:include and require are both included and run files, but there is a difference.

If the included file does not exist,include will report a warning error and the script continues to run down.

require will report a fatal error, and the script will immediately terminate execution.

3.Header ()

L Description: send a custom http message , in other words:the format or character set of the data returned by PHP.

L Syntax:void Header (string $string)

L Example:

U header ("Content-type:text/html;charset=utf-8")// set The character set of PHP return data

U header ("location:http:www.sina.com.cn"); page Jump

jump inu JS: location.href = "http://www.sina.com.cn"

U HTML Jump:<meta http-equiv = "Refresh" content = "2;url = http://www.sina.com.cn" >

URL Uniform Resource Locator.

http://www.sina.com.cn/index.php ? Username=yao & Userpwd=123456#top

? before is the file name. ? followed by a query string.

query string:? username=yao&userpwd=123456//location.search

after the query string, it is the anchor name. such as:#top

3.Header ()

L Description: send a custom http message , in other words:the format or character set of the data returned by PHP.

L Syntax:void Header (string $string)

L Example:

U header ("Content-type:text/html;charset=utf-8")// set The character set of PHP return data

U header ("location:http:www.sina.com.cn"); page Jump

jump inu JS: location.href = "http://www.sina.com.cn"

U HTML Jump:<meta http-equiv = "Refresh" content = "2;url = http://www.sina.com.cn" >

URL Uniform Resource Locator.

http://www.sina.com.cn/index.php ? Username=yao & Userpwd=123456#top

? before is the file name. ? followed by a query string.

query string:? username=yao&userpwd=123456//location.search

after the query string, it is the anchor name. such as:#top

UrlEncode ()

Description: encoded URL string

Syntax: String UrlEncode (String $str)

Description: Returns the string, in addition to-_, in this string . all non-alphanumeric characters will be replaced with a percent ( % ) followed by a two-digit hexadecimal number, the space is encoded as a plus sign ( + ).

Example:urlencode (" period ") =%e7%ac%ac32%e6%9c%9f

UrlDecode ()

Description: decoding an encoded URL string

Syntax: string urldecode (String $str)

5.MySQL database Operation steps