PDO (20161107)

Pdo

Mysqli is for MySQL database extension, is specifically to access the MySQL database

PDO is an extended class of database access that accesses multiple databases through a single class, which is a data access abstraction layer that combines classes

can access other databases, which is the abstraction layer of data access

<! DOCTYPE html Public"-//w3c//dtd XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >PHP//PDO//1. Access to different database//2. The transaction function can be restored by a rollback operation. To prevent SQL injection//pdo from being used ./*//1. Object $dsn = "Mysql:dbname=mydb;host=localhost"; " Driver Name: Database name, server address "$pdo = new PDO ($DSN," root "," 123 "),//2. Write SQL statement $sql =" Update Nation set Name= ' orc ' where code= ' n013 ' ";//3. Executes the SQL statement//$r = $pdo->query ($sql), returns another object after executing the query, and needs to find "= $pdo->exec ($sql) through another object;*///The transaction function is either fully executed or all failed//created$dsn= "Mysql:dbname=1016;host=localhost";$pdo=NewPDO ($dsn, "root", "Database Password");//set the exception mode, throw an exception if an error occurs$pdo->setattribute (pdo::attr_errmode,pdo::errmode_exception);/*Set Property (name, value) Note Do not enclose double quotation marks*///Write SQL statements$sql 1= "INSERT into nation values (' n007 ', ' Korean ')";$sql 2= "INSERT into nation values (' n008 ', ' Yi ')";//start a transaction, execute two SQL statements, eventually commit to the transaction, and then the transaction will determine if there is a problem and throw the problem if there is a problemTry//try to do it.{    //Start a transaction    $pdo-BeginTransaction (); $pdo-exec($sql 1); $pdo-exec($sql 2); //Commit a transaction    $pdo-commit ();}Catch/*caught*/(pdoexception$e)//a type of PDO throw{    //$e->getmessage (); Show error message// rollback    $pdo-rollBack ();}/*final//Final execution of the content, out of error are executed, the general write off code (PHP is not common) {}*/?></body>1107test.php
<! DOCTYPE html Public"-//w3c//dtd XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >PHP//created Objects$dsn= "Mysql:dbname=1016;host=localhost";$pdo=NewPDO ($dsn, "root", "Database Password");//Write SQL statements, preprocessing statements$sql= "SELECT * From Nation";//ready to execute$st=$pdo->prepare ($sql);//Execution$st-execute ();//read data fetch one line or fetch allVar_dump($st->fetchall (PDO::Fetch_assoc));?></body>1107chaxun.php
<! DOCTYPE html Public"-//w3c//dtd XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >PHP//created Objects$dsn= "Mysql:dbname=1016;host=localhost";$pdo=NewPDO ($dsn, "root", "Database Password");//Write SQL statements, pre-processing statements, using the name placeholder (name placeholder) preceded by a colon$sql= "INSERT into nation values (: Code,:name)";//ready to execute$st=$pdo->prepare ($sql);//Binding Parameters/*$st->bindparam (": Code", $code, PDO::P aram_str); $st->bindparam (": Name", $name, PDO::P aram_str); $code = " n011 "; $name =" Tujia nationality ";*///using associative arrays$attr=Array("Code" = "n012", "name" = "Buyi");//Execution$st->execute ($attr);//Summary: Name placeholder, with an associative array;? placeholder, indexed array of?></body>1107namezhanwei.php
<! DOCTYPE html Public"-//w3c//dtd XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" >PHP//created Objects$dsn= "Mysql:dbname=1016;host=localhost";$pdo=NewPDO ($dsn, "root", "Database Password");//Write SQL statement, preprocessing statement with question mark occupy position$sql= "INSERT into nation values (?,?)";//prepares the SQL statement to return the statement object with a variable to receive the returned statement object$st=$pdo->prepare ($sql);//bind parameter bind binding param parameter starting from 1 index with question mark stance/*Simplified Pre-$st->bindparam (1, $code), $st->bindparam (2, $name);//Can be assigned in the back or in front $code= "n022"; $name = "Dwarf clan" ;*///simplified array of arrays$attr=Array("n010", "Mongolian");//commit execution, not to SQL statements, has passed.Var_dump($st->execute ($attr));//Execute successfully returns TRUE if the failed return false//preprocessing statement is used in the. placeholder, give the array the time to give the index array, order to correspond to?></body>1107sqlzhuru.php
PDO (20161107)