亚洲国产日韩欧美一区二区三区,精品亚洲国产成人av在线,国产99视频精品免视看7,99国产精品久久久久久久成人热,欧美日韩亚洲国产综合乱

PHP MySQL ???

WHERE ?? ???? ????? ? ?????. ?? ??? ??? ?? ???? ???? ????


??

< table width=" -642">
    類型    詳細(xì)解釋
   基本語法 select 字段 from 表 where where條件;
   示例select * from money where age = 29;
   示例說明查詢MyGuests表中年齡為29的所有結(jié)果
?? ??? ?? ?? ?? ??? ?? ????? ?? ?? ??? = 29? ??? * ??; < td width="193" valign="top" style="border-width: 1px; border-style: solid; word-break: break-all;"> ?MyGuests ????? 29?? ?? ??? ?????

?? ?? ???????.

?

?? ?? "MyGuests" ????? ?? FirstName? ????? =' Mary' ?:

<?php
 header("Content-type:text/html;charset=utf-8");    //設(shè)置編碼
 $servername = "localhost";
 $username = "root";
 $password = "root";
 $dbname = "test";
 $con=mysqli_connect($servername, $username, $password, $dbname);
 // 檢測(cè)連接
 if (mysqli_connect_errno())
 {
     echo "連接失敗: " . mysqli_connect_error();
 }
 
 $result = mysqli_query($con,"SELECT * FROM MyGuests
 WHERE FirstName='Mary'");
 
 while($row = mysqli_fetch_array($result))
 {
     echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email'];
     echo "<br>";
 }
 ?>

???? ?? ??:

4.png


??? ??? ???? FirstName='Mary'? ?? ???? ???? ????.

?? phpadmin? ???? MyGuests ???? Age ??? ?????.

?? ???? ???? ??? ????.

14.png

?

?? where ?? ???? Age? 25? ??? ???? ?????.

<?php
 header("Content-type:text/html;charset=utf-8");    //設(shè)置編碼
 $servername = "localhost";
 $username = "root";
 $password = "root";
 $dbname = "test";
 $con=mysqli_connect($servername, $username, $password, $dbname);
 // 檢測(cè)連接
 if (mysqli_connect_errno())
 {
     echo "連接失敗: " . mysqli_connect_error();
 }
 
 $result = mysqli_query($con,"SELECT * FROM MyGuests
 WHERE Age<25 ");
 
 while($row = mysqli_fetch_array($result))
 {
     echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email']."----".$row['Age'];
     echo "<br>";
 }
 ?>

???? ?? ??:

1.png

?? ??? ??? ?? ????

< /tr>
     符號(hào)     說明
     >  大于
     <  小于
     >=  大于等于
     <=  小于等于
??
??
> ?? ?
< ??
> = ??? ??
<= ??? ??
     !=  不等于
     =   等于

?? ???

< td width="193" valign="top" style="border-width: 1px; border-style: solid; word-break: break-all;"> ?
       符號(hào)      說明
     or   或者
     and    并且

??

??
?? ??
???

?? ?? ??? ?? ??????.

?

9.png

'firstname'='Julie' ? Age? ???? ?????. =24 ???
<?php
 header("Content-type:text/html;charset=utf-8");    //設(shè)置編碼
 $servername = "localhost";
 $username = "root";
 $password = "root";
 $dbname = "test";
 $con=mysqli_connect($servername, $username, $password, $dbname);
 // 檢測(cè)連接
 if (mysqli_connect_errno())
 {
     echo "連接失敗: " . mysqli_connect_error();
 }
 
 $result = mysqli_query($con,"SELECT * FROM MyGuests
 WHERE Firstname='Julie' AND Age=24 ");
 
 while($row = mysqli_fetch_array($result))
 {
     echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email']."----".$row['Age'];
     echo "<br>";
 }
 ?>
???? ?? ??:
???? ??
||
<?php header("Content-type:text/html;charset=utf-8"); //設(shè)置編碼 $servername = "localhost"; $username = "root"; $password = "root"; $dbname = "test"; $con=mysqli_connect($servername, $username, $password, $dbname); // 檢測(cè)連接 if (mysqli_connect_errno()) { echo "連接失敗: " . mysqli_connect_error(); } $result = mysqli_query($con,"SELECT * FROM MyGuests WHERE FirstName='Mary'"); while($row = mysqli_fetch_array($result)) { echo $row['firstname'] . "----" . $row['lastname'] ."----".$row['email']; echo "<br>"; } ?>