1.PHP操作MySQL数据库类

/*1.测试是否建立起连接*/

$hostname = "localhost";

$usr = "root";

$pw = "321";

$link = mysql_connect($hostname,$usr,$pw) or die(mysql_error());

if($link)

{

       echo "ok";

}else {

       echo "down";

}

mysql_close($link);

/*2.测试连接是否存活 */

$link = mysql_connect("localhost","root","321");

$isok = mysql_ping($link);

if($isok){

       echo "the server is ok";

}else{

       echo "the server is down";

}

/*3. 建立连接之后执行一个查询SQL语句得到结果集之后显示其中的记录信息*/

$link = mysql_connect("localhost","root","321");

mysql_query("set names gb2312");

mysql_select_db("php");

$sql="select * from test";

$result = mysql_query($sql);

while($row = mysql_fetch_array($result))

{

       echo "id is :".$row[id]." and the name is:".$row[name]."
";

}

//释放结果

mysql_free_result($result);

/*4. 实现类似JAVA中的方式哦。*/

$link = mysql_connect("localhost","root","321");

mysql_query("set names gb2312");

mysql_select_db("php");

$sql=sprintf("select * from test where name='%s'",mysql_real_escape_string("d"));

$result = mysql_query($sql);

while($row = mysql_fetch_array($result))

{

       echo "id is :".$row[id]." and the name is:".$row[name]."
";

}

//释放结果

mysql_free_result($result);

 

/*5.如果SQL执行之后只有一条记录的话那就没有必要进行WHILE操作了。*/

$link = mysql_connect("localhost","root","321");

if(is_resource($link))

{

       mysql_query('SET NAMES gb2312;');

       mysql_select_db("php");

       $sql = "select * from test where name='d'";

       $result = mysql_query($sql);

       echo "id is:".mysql_result($result,0,"id")."
";

       echo "name is:".mysql_result($result,0,"name")."
";

}else{

       $ping = mysql_ping($link);

       if($ping)

       {

              echo "ping ok";

       }else{

              echo mysql_error();

       }

}

//突然发现PHP中的函数实在是有些多的。所以要总结！

/*6. 执行更新SQL语句。比如DELETE操作计算影响的行数*/

$link = mysql_connect("localhost","root","321");

mysql_query("set names gb2312");

mysql_select_db("php");

$sql = "delete from test where id=1";

mysql_query($sql);

echo "影响的行数:".mysql_affected_rows();

mysql_close($link);

/*7.得到当前数据库中全部可用数据库*/

$link = mysql_connect("localhost","root","321");

$db_list = mysql_list_dbs($link);                //获取到一个DB的列表出来的。

$dbNum = mysql_num_rows($db_list);           //提取出来数目

while($i<$dbNum)

{

       echo mysql_db_name($db_list,$i)."\n";

       echo "

\n";

       $i++;

}

/*9. 获取字段的长度*/

$link = mysql_connect("localhost","root","321");

mysql_select_db("php");

$sql="select * from test where id=3";

$result=mysql_query($sql);

$length = mysql_field_len($result,1);

echo "字段长度为:".$length;

/*10.获取当前操作表名*/

$link = mysql_connect("localhost","root","321");

mysql_select_db("php");

$sql="select * from test where id=3";

$result=mysql_query($sql);

$table=mysql_field_table($result,1);

echo "The table name is:".$table;

/*11.对数据表中的字段的一些操作*/

$link=mysql_connect("localhost","root","321");                 //打开Mysql连接

mysql_select_db("php");                                                               //选择数据库

$result=mysql_query("SELECT * FROM test");                              //执行查询

$fields=mysql_num_fields($result);                                                       //获取字段数

$table=mysql_field_table($result,0);                                                       //获取表名

for($i=0;$i<$fields;$i++)                                                                      //循环读取记录

{

  $type=mysql_field_type($result,$i);                                            //获取字段类型

  $name=mysql_field_name($result,$i);                                                //获取字段名

  $len=mysql_field_len($result,$i);                                                       //获取字段长度

  $flags=mysql_field_flags($result,$i);                                           //获取字段标识

  echo $type." ".$name." ".$len." ".$flags."\n";                                       //输出信息

  echo "

";

}

mysql_free_result($result);                                                            //释放结果集

mysql_close();                                                                                    //关闭连接