Introduction to PDO, Flower thousand bones Synopsis _php Tutorial

Introduction to PDO, flowers thousand bones synopsis

PHP link database After six months need to replace MySQL for cluster mode or have the money to upgrade the ORACL database, when the changes are quite large, high cost. If you use PDO before, it's easy to meet the problem again.

To turn on PDO:

Open the php.ini file, you will need to open the DLL extension in front of the ";" Remove.

; Extension=php_pdo_firebird.dll

; Extension=php_pdo_mysql.dll

; Extension=php_pdo_oci.dll

; Extension=php_pdo_odbc.dll

Test can be used

Open Php.info () to see:

Using syntax

$db->setattribute (Pdo::attr_case, PDO::case_upper); $rs $db->query ("SELECT * from foo"); $rs->setfetchmode (PDO::fetch_assoc); $result _arr $rs-Fetchall (); Print_r ($result _arr);

SetAttribute ():

Pdo::case_lower--Force column names to be lowercase
Pdo::case_natural--column names are in the original way
Pdo::case_upper--Force column name to uppercase

Setfetchmode ():

PDO::FETCH_ASSOC--Associative array form
Pdo::fetch_num--Digital Index array form
Pdo::fetch_both--both array form, this is the default
Pdo::fetch_obj-In the form of an object, similar to the previous mysql_fetch_object ()

Exception handling:

Try{    $db=NewPDO ($dsn,$user,$passwd);}Catch(pdoexception$e){    Print $e->getmessage ();//Return exception Information    Print $e->getcode ();//return Exception Code    Print $e->getfile ();//returns the file name of the exception that occurred    Print $e->getline ();//returns the line number of the code where the exception occurred    Print $e->gettrace ();//backtrace () array    Print $e->gettraceasstring ();//Gettrace () information that has been rasterized into a string}$count=$db-exec("INSERT into Info_u set name,nickname = ' Hefe ', job=1;");Print $db-ErrorCode ();Print_r($db-errorinfo ());--------------------------------------------------

[message:protected] = sqlstate[hy000] [1045] Access denied for user ' coffee ' @ ' localhost ' (using Password:yes)

[String:Exception:private] =

[Code:protected] = 1045

[File:protected] =/alidata/www/webpage/signup.php

[Line:protected] = 11

[Trace:Exception:private] = = Array

(

[0] = = Array

(

[File] =/alidata/www/webpage/signup.php

[Line] = 11

[Function] = __construct

[Class] = PDO

[Type] =

[Args] = Array

(

[0] = Mysql:host=localhost;dbname=fengchao

[1] = coffee

[2] = Coffe

)

)

)

[Previous:Exception:private] =

[ErrorInfo] =

42s22

Array (    [0] = = 42s22    [1] = 1054    [2]= = ' name ' in ' Field List ' ) 

In the new link, exception handling is performed with Pdoexception (); Exception handling using ErrorInfo () and errorcode () when executing exection ();

ErrorCode () returns:

00000//Perform normal

1054//unknown column ' x ' in ' Field List ' fields X does not appear in the field

1110//field appears two times two times

1062//duplicate entry ' X ' for key ' PRIMARY ' repeating primary key

......

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