PHP operation MySQL

One, Tianlong eight steps

1. Connect to MySQL Database

1 $link=mysqli_connect("localhost", "root", "Meiyoumima");

2. Determine if the connection is successful

1 if ($link) {23echo "database connection succeeded! "; 4 }else{56die ("Database connection Failed"); 7 } 　　　　　　 　　　　　　

3. Setting the character set

1 mysqli_set_charset ($link, "UTF8");

4. Select a database

1 mysqli_select_db ($link, "demo");

5. Preparing SQL statements

1 $sql= "SELECT * from Stu";

6. Send SQL statements to the MySQL service

1 $result=mysqli_query($link,$sql); 　

7. Parse the result set

1 Echo"<center>";2     Echo";3     Echo"<table border= ' 1 ' width= ' >";4         Echo"<tr>";5             Echo"<th>ID</th>";6             Echo"<th> name </th>";7             Echo"<th> Gender </th>";8             Echo"<th> Age </th>";9             Echo"<th> class </th>";Ten             Echo"<th> Operations </th>"; One         Echo"</tr>"; A          -     //5. Parse the result set -     if($result&&mysqli_num_rows($result) >0){ the          while($rows=Mysqli_fetch_assoc($result)){ -             Echo"<tr align= ' center ' >"; -                 Echo"<td>{$rows[' ID ']} </td> "; -                 Echo"<td>{$rows[' Name ']} </td> "; +                 Echo"<td>{$rows[' Sex ']} </td> "; -                 Echo"<td>{$rows[' Age ']} </td> "; +                 Echo"<td>{$rows[' ClassName ']} </td> "; A                 Echo"<td> at <a href= ' # ' > Edit </a> - <a href= ' # ' > Delete </a> -</td> "; -             Echo"</tr>"; -         } -}Else{ in          die("No data is queried!") "); -     } to     Echo"</table>"; +     Echo"</center>";

8. Release the result set and close the database connection

1 Mysqli_free_result ($result); 2 Mysqli_close ($link); 　　 　　

Two or six-pulse Excalibur

1  　　 //1. Connect to the database server (if the connection succeeds as an object, if it fails, it returns a false)2     $link=Mysqli_connect("localhost", "root", "Meiyoumima") or die("Database connection failed! ");3     4     //2. Setting the Encoding5Mysqli_set_charset ($link, "UTF8");6     7     //3. Select a database8     mysqli_select_db($link, "Demo");9     Ten     //4. Define the SQL statement and send execution (if the send execution succeeds, is an object, if it fails, is a false) One     $sql= "SELECT * from Stu;"; A     $result=Mysqli_query($link,$sql); -      -     Echo"<center>"; the     Echo"; -     Echo"<table border= ' 1 ' width= ' >"; -         Echo"<tr>"; -             Echo"<th>ID</th>"; +             Echo"<th> name </th>"; -             Echo"<th> Gender </th>"; +             Echo"<th> Age </th>"; A             Echo"<th> class </th>"; at             Echo"<th> Operations </th>"; -         Echo"</tr>"; -          -     //5. Parse the result set -     if($result&&mysqli_num_rows($result) >0){ -          while($rows=Mysqli_fetch_assoc($result)){ in             Echo"<tr align= ' center ' >"; -                 Echo"<td>{$rows[' ID ']} </td> "; to                 Echo"<td>{$rows[' Name ']} </td> "; +                 Echo"<td>{$rows[' Sex ']} </td> "; -                 Echo"<td>{$rows[' Age ']} </td> "; the                 Echo"<td>{$rows[' ClassName ']} </td> "; *                 Echo"<td> $ <a href= ' # ' > Edit </a>Panax Notoginseng <a href= ' # ' > Delete </a> -</td> "; the             Echo"</tr>"; +         } A}Else{ the          die("No data is queried!") "); +     } -     Echo"</table>"; $     Echo"</center>"; $     //6. Close the database and release the result set -     Mysqli_free_result($result); -     Mysqli_close($link);

Three, common function operation

1. Mysqli_connect ();--Connect to the database and return a connection resource
Format: mysql_connect (host name, user, password);
--where parameters are optional, if not written, refer to the default configuration in php.ini

2. Mysqli_error (); --Get the error message just (last) to perform the database operation

3. Mysqli_errno (); --Get the error number that just (last) performed the database operation
Error number 0 means no error

4. mysqli_select_db (database name [, database connection]);
Select a database, equivalent to the Use library name statement

5. Mysqli_set_charset (character encoding);--Set character encoding
For example: Mysql_set_charset ("UTF8"); Equivalent to: mysql_query ("Set names UTF8");

6. Mysqli_query (SQL statement [, database connection]);--Send an SQL statement
If the SQL statement is queried, the result set is returned, and the other returns a Boolean value indicating whether the execution was successful.

7. Parse the result set function:
Mysqli_fetch_array (); ---parsing a result set in both associative and indexed arrays can also specify a second parameter to define the return format:
Mysql_both (0 associations and indexes)/mysql_num (2 index)/MYSQL_ASSOC (1 associations)

Mysqli_fetch_row (); --Parse the result set in an indexed array
*mysqli_fetch_assoc (); --parse result set with associative array
Mysqli_fetch_object (); --Parse the result set in object mode

8. Mysqli_free_result (Result set name);--release result set

9. Mysqli_close (database connection); --Close database connection

Mysqli_num_rows (result set); --Gets the number of data bars in the result set (specifically for queries)

Mysqli_num_fields (result set); --Get the number of columns in the result set (number of fields)

Mysqli_result (); --Positioning results
Echo Mysqli_result ($result, 0, 3). " <br/> "; Gets the value in the 4th column of the 1th piece of data
Echo Mysqli_result ($result,.). " <br/> "; Gets the value in the 3rd column of the 2nd piece of data
Echo Mysqli_result ($result, 5,4). " <br/> "; Gets the value in the 5th column of the 6th piece of data

13.mysqli_affected_rows-gets the number of record rows affected by the Insert,update or DELETE query associated with the number of record rows affected by the previous MySQL operation.

Mysqli_insert_id-get the ID from the previous insert operation

PHP operation MySQL