Learning purpose: Learn to read data
Let’s look at two functions first:
1、mysql_query
Send a query string. Syntax: int mysql_query(string query, int [link_identifier]); Return value: integer
This function sends out a query string for MySQL to do related processing or execution. If the link_identifier parameter is not specified, the program will automatically look for the recently opened ID. When the query query string is UPDATE, INSERT and DELETE, the returned may be true or false; if the query string is SELECT, the new ID value is returned. When false is returned, it does not execute successfully but no return value, but the query string has an error.
2. mysql_fetch_object returns class information. Syntax: object mysql_fetch_object(int result, int [result_typ]); Return value: class
This function is used to split the query result into a class variable. If result has no data, return false.
Let's take a look at a simple example:
<?
$exec="select * from user";
$result=mysql_query($exec);
while($rs=mysql_fetch_object($result))
{
echo "username:".$rs->username."<br>";
}
?>
Of course, there is a username field in the table user, which is similar to the
<%
exec="select * from user"
set rs=("")
exec,conn,1,1
do while not
"username:"&rs("username")&"<br>"
loop
%>
Of course, we need to connect to the database first. Generally, we require_once(''); and it is the code for connecting to the database mentioned last time.
Two small commands can complete the work of reading data. Today, let’s talk about the addition, deletion and modification of data.