Encapsulation of database operations in PHP_PHP tutorial

Encapsulation of database operations in PHP

A lot of dynamic web design involves database operations, but sometimes if other background databases are used as needed, a lot of program modifications are required. This is a tedious, time-consuming and error-prone task. In fact, we can use classes in PHP to encapsulate database operations, so that the written program can complete changes to the background database with very small changes.
Now we encapsulate it in dbfz.inc, and its design is as follows:

class dbInterface{ var $dbID=1; //Used to determine the database for the current operation, when When the dbID is 1, it represents MySql, when it is 2, it represents SQL Server, when it is 3, it represents ODBC or others.
var $dbHost; //The domain name of the host where the database is located
var $dbUsername; //Database user name
var $dbPassword; //User password
//Set the host, username and password functions
function setParameter($host,$username,$password){
$this->dbUsername=$username;
$this->dbHost=$host;
$this->dbPassword =$password;

} //Connection database function
function dbConnect(){
switch($this->dbID)
{
case 1;
return @mysql_connect($this->dbHost,$this->dbUsername,$this->dbPassword);
case 2;
//Use functions that support SQL Server
case 3;
//Use functions that support ODBC
}
}
//Close the database function
function dbClose($dataHandle){
switch($this->dbID)
{
case 1;
mysql_close($dataHandle);
case 2;
//Use functions that support SQL Server
case 3;
//Use functions that support ODBC
}
}

//Execute SQL statement function
function dbQuery($dbName,$sql,$dbHandle){
switch($this->dbID)
{
case 1;
return @mysql_db_query($dbName,$sql,$dbHandle);
case 2;
//Use functions that support SQL Server
case 3;
//Use functions that support ODBC
}
}

//Retrieve the current record function of the SQL return value
function dbFetchrow($dataHandle,$offset=-1){
switch($this->dbID)
{
case 1;
@mysql_data_seek($dataHandle,$offset);
return @mysql_fetch_row($dataHandle);
case 2;
//Use a function that supports SQL Server
case 3;
//Use a function that supports ODBC
}
}

//Return the function to retrieve the number of records
function dbNumrows($dataHandle){
switch($this->dbID)
{
case 1;
return @mysql_num_rows($dataHandle);
case 2;
//Use functions that support SQL Server
case 3;
//Use functions that support ODBC
}
}

//Return to retrieve column number function
function dbNumcols ($dataHandle){
switch($this->dbID)
{
case 1;
return @mysql_num_fields($dataHandle);
case 2;
//Use Functions that support SQL Server
case 3;
//Use functions that support ODBC
}
}
}

The usage instructions are as follows:

Use the dbInterface class in the program to generate an object $test=new dbInterface;

Set parameters
test->$dbUsername; Username
test->$dbPassword; Password
test->$dbHost; host
void setParameter(string host, string username, string password);

Database connection: dbhandle test->dbConnect();

return value :fasle, database connection error
>0, database connection handle

database closed: void test->dbClose(dbhandle);

table operation: int test->dbQuery (string databasename, string sql, dbhandle); Execute SQL statement

return value: false, SQL execution error
>0, SQL execution is correct, and point to the SQL return value,

Data operation: int test->dbFetchrow(dataHandle, int offset); Retrieve the current record of SQL return value. After successful execution, the pointer moves to the next record
int test->dbNumrows(dataHandle); Get SQL execution The number of records obtained after (mainly SELECT statements)
int test->dbNumcols(dataHandle); The number of record fields obtained after SQL execution (mainly SELECT statements)

Now let’s send an example Explanation:

The database uses MQSQL: its host name is "localhost", user name is "root" and password is "".
There is a testdb database and table table1 in mysql. The table includes: name and pay fields

-----

require("testdb.inc"); //Load dbInterface class
$test = new dbInterface;//Generate an object using class dbInterface
$test->setParameter("localhost","root","");//Set database parameters
$db = $ test->dbConnect();//Connect to the database
$Query = "SELECT name,pay FROM table ";//Set SQL statement
$temp_result = $test->dbQuery("testdb",$ Query,$db); //Perform data master database operation
echo "
";
$ls_num = $test->dbNumrows($temp_result); //Get the number of records in the query result
echo $ls_num;
echo "
";
if (ls_num>0 )
{
$ls_col = $test->dbNumcols($db); //Get Number of columns in the table
echo $ls_col;
echo "
";
$cate_result=$test->dbFetchrow($temp_result,0);//Get the first row of the number of records
$hcid=$cate_result[0];//Get the value of name
$hcate=$cate_result[1];//Get the value of pay
echo $hcid;
echo "< br>";
echo $hcate;
}

?>