Interested in the open-source community and php. I have a little time to understand the simple functions of php.
Topic: Simple PHP functions
Brief introduction: PHP is simple and clear function syntax
Suitable for: interested in open-source communities, php, and a little time to learn about php
Note: I hope you can still give bricks.
1. related to mysql
Mysql_connect
Establish a connection with the MySQL server
Syntax
The code is as follows:
Resource mysql_connect (string server [, string usingname [, string password [, bool new_link [, int client_flags])
Eg:
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_data_seek
Move the internal query pointer to the query row
Syntax
The code is as follows:
Bool mysql_data_seek (resource result_indetifier, int row_number)
Eg:
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ DB_NAME = "flag ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_select_db ($ DB_NAME );
$ Res = mysql_query ("SELECT * from product ");
$ Row = mysql_fetch_array ($ res );
For ($ I = 0; $ I <$ num; $ I ++)
$ Row = mysql_fetch_array ($ res );
Mysql_data_seek ($ res, 0); // move the pointer back to the first row of the query result
Mysql_fetch_array
Store the query results in an array (one record for each array element)
Syntax
The code is as follows:
Array mysql_fetch_array (resource result [, int result_type])
Eg
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ DB_NAME = "flag ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_select_db ($ DB_NAME );
$ Res = mysql_query ("SELECT * from product ");
$ Row = mysql_fetch_array ($ res );
Mysql_fetch_object
A row of query results is obtained and stored as an object. the usage of MySQL_fetch_array () is the same. The difference is that mysql_fetch_object () can only obtain query results by field name.
Echo $ row-> fieldname; // correct usage
Echo $ row-> 0; // Incorrect usage
Syntax
The code is as follows:
Object mysql_fetch_object (resource result)
Eg
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ DB_NAME = "flag ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_select_db ($ DB_NAME );
$ Res = mysql_query ("SELECT * from product ");
$ Row = $ mysql_fetch_object ($ res );
While ($ row)
{
Echo $ row à p _ id;
Echo $ row à p _ name;
}
Mysql_insert_id
After adding a message using the INSERT command, you can use this function to obtain the unique id of the newly added record.
Syntax
The code is as follows:
Int mysql_insert_id ([esource link_identifier])
Eg
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ DB_NAME = "flag ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_select_db ($ DB_NAME );
$ SQLStr "insert into produce (p_id, p_name) VALUES ('', 'php book ')";
$ Res = mysql_query ($ res );
$ P_id = mysql_insert_id ();
Mysql_num_rows
There are several rows in the query result.
Syntax
The code is as follows:
Int mysql_num_rows (resource result)
Eg
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ DB_NAME = "flag ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_select_db ($ DB_NAME );
$ Res = mysql_query ("SELECT * from product ");
$ Num = mysql_num_rows ($ res );
Mysql_query
Send a query statement of SQL syntax
Syntax
The code is as follows:
Resource mysql_query (string query [, resource link_identifier])
Eg
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ DB_NAME = "flag ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_select_db ($ DB_NAME );
$ Res = mysql_query ("SELECT * from product ");
Mysql_select_db
Select the name of the database to be accessed
Syntax
The code is as follows:
Bool mysql_select_db (string database_name [, resource link_identifier])
Eg
$ DB_HOST = "localhost ";
$ DB_LOGIN = "root ";
$ DB_PASSWORD = "123456 ";
$ DB_NAME = "flag ";
$ Conn = mysql_connect ($ DB_HOST, $ DB_LOGIN, $ DB_PASSWORD );
Mysql_select_db ($ DB_NAME );
2. file system functions
Copy
Copy text
Syntax
Bool copy (string source, string dest)
Eg
Copy(“abc.txt ","/tmp/newabc.txt ");
Fclose
Close a pointer to open a file
Syntax
Bool fclose (resource handle)
Eg
$Fpw.fopen(“abc.txt "," w ");
Fclose ($ fp );
Fgets
Retrieve the column content from the position indicated by the file pointer
Syntax
String fgets (resource handle [, int length])
Eg
$Fpw.fopen(“abc.txt "," w ");
$ Txtdata = fgets ($ fp, 4096 );
File
Read the entire file content to the array
Syntax
Array file (string filename [, int use_include_path [, resource context])
Eg
$Content1_file(“abc.txt ");
File_exists
Check whether the file exists
Syntax
Bool file_exists (string filename)
Eg
If (file_exists(“abc.txt "))
Echo "this file exists ";
Else
Echo "this file does not exist ";
Filesize
Get file size
Syntax
Int filesize (string filename)
Eg
Inclusizeinclufilesize(“abc.txt ");
Fopen
Open a file or url
Syntax
Resource fopen (string filename, string mode [, bool use-include_path [, resource zcontext])
Eg
$Fp=fopen(“abc.txt ");
$ Fp = fopen ("http://www.jb51.net/bacteroid/", ”r ");
Fputs
Write data to a file
Syntax
Int fputs (resource handle, string [, int length])
Eg
$Fp=fopen(“abc.txt ");
Fputs ($ fp, "helloworld !");
Fseek
Set the position indicated by the file pointer
Syntax
Int fseek (resource handle, int offset [, int whence])
Eg
$Fpw.fopen(“abc.txt "," w ");
$ Txtdata = fgets ($ fp, 4096 );
Fseek ($ fp, 0); // point the pointer back to the starting position
Mkdir
Create a directory
Syntax
Bool mkdir (string pathname [, int mode [, bool recursive [, resource context])
Eg
Mkdir ("ljt/newfolder ");
Unlink
Delete an object
Syntax
Int unlink (string filename );
Eg
Unlink(cmdabc.txt ");
3. date and time functions
Data
Returns the local time/date in the specified format.
Syntax
String date (string format [, int timestamp])
Eg
$ Time = date ("Y-m-d g: I: s ");
Getdate
Obtain date and time information
Syntax
Array getdata ([int timestamp])
Eg
$ Now = getdate ();
$ Year = $ now ["year"];
$ Month = $ now ["month"];
Gettimeofday
Obtain the current time (including Greenwich Mean Time)
Syntax
Array gettimeofday (void)
Eg
$ Time = gettimeofday ();
4. string processing functions
Explode
Splits a string into an array based on the specified delimiter.
Syntax
Array explode (string separator, string [, int limit])
Eg
$ Str = "a, B, c ";
$ Res = explode (",", $ str); // $ res [0] =
Implode
Concatenates the array content into a string
Syntax
String implode (string glue, array pieces)
Eg
$ Newarray = array ('A', 'B', 'C ');
$ Res = implode (",", $ newarray); // $ res = a, B, c
Strlen
Returns the length of a string.
Syntax
Int strlen (string)
Eg
Strlen ("www.gxnu.edu.cn"); // returns 15
Substr
Obtains a specified part of the character string (sub-string)
Syntax
String substr ("www.gxnu.edu.cn",); // return "ww. gxnu"
5. mathematical function library
Ceil
Unconditionally carry the decimal part of the floating point number
Syntax
Float ceil (float value)
Eg
Echo ceil (9.99); // returns 10
Echo ceil (9.12); // returns 10
Cos
Returns the cosine of a floating point value.
Syntax
Float cos (float arg)
Eg
$ Numcos = cos (0.5 );
Floor
Remove the decimal part of the floating point number unconditionally.
Syntax
Float floor (floor value)
Eg
Echo floor (9.12); // return 9
Echo floor (9.99); // return 9
Rand
Generates a random value in a range.
Syntax
Int rand ([int min, in max])
Eg
$ Num = rand (0,100); // generates a random value between 1 and 100.
Round
Rounds the decimal part of a floating point number to carry.
Syntax
Float round (float value)
Eg
Float round (9.99) // returns 10
Float round (9.12) // return 9
Sin
Returns the sine of a floating point value.
Syntax
Float sin (float arg)
Eg
$ Numsin = sin (0.5 );
6. Session functions
Session_register
Description: variables in one or more sessions
Syntax
Bool session_register (mixed name [, mixed...])
Eg
$ Name = "flag ";
Session_register ("name ");
Session_start
Initialize Session information
Syntax
Bool session (void)
Eg
Session_start ();
7. array functions
Count
There are several array functions in the calculation array.
Syntax
Int count (mixed var [, int mode])
Eg
Count ($ array );
List
Assign the element values in the array to the variable.
Syntax
Void list (mixed varname, mixed ...)
Eg
$ Array = array (a, B, c );
List ($ str1, $ str2, $ str3) = $ array; // $ str1 =
Range
Creates an array within the specified range.
Syntax
Array range (int low, int high [, int step])
Eg
$ Array = array (0, 9 );
Shuffle
Re-random sorting of elements in the array
Syntax
Bool shuffle (array)
Eg
Shuffle ($ array );
