PHP Basics Tutorial--5 Database Summary

1. Connection to the database

$DBC = mysql_connect (hosetname, username, password);

2.Mysql Error Handling

Mysql_error (); Informative report showing errors

3. Create and select a database

Create: mysql_query (' Create DATABASE somedb ');

Checked: mysql_select_db ("Somedb"); Check the database before you run the query

4. Create a table

$query = "Create TABLE my_table (id INT PRIMARY KEY, information TEXT); Assign the creation statement first to a variable

mysql_query ($query);//Then put the variable into the mysql_query () function

5. Inserting data

With the CREATE table, each query assigns a variable and then passes the variable to the mysql_query () function:

$query = "INSERT into entries (entry_id, title, entry, data_entered) VALUES (0," title "," $entry ", Now ())";

mysql_query ($query);

6. Secure query data

For a query entered by a user, use Mysql_real_escape_string ($var) to escape a potentially dangerous character such as a single quotation mark (which will be preceded by a backslash)

7. Retrieving data from a database

You need to copy the results of the query to a variable:
$query = "SELECT * from users WHERE (name = MyName)";

$result = MySQL ($query);

8. Delete Data

$query = "DELETE from users WHERE name = myname LIMIT 1";

$result = MySQL ($query);

9. Update

$query = UPDATE tablename SET column1 = value, Colunmn2 = value WHERE some_column = value ";

$result = MySQL ($query);

Coded test: ws.php

 
 
 

 
  
  
<title>Test</title> 
 
 



 -->
Connect to the database and select
if ($dbc = @mysql_connect (' localhost ', ' root ', ')} {
	if (@mysql_select_db (' MyData ')) {
		print '
selected!
';
	} else{
		print '
Can not select error: '. Mysql_error (). '
';
	}
} else{
	print '
Can not connect. Error: '. Mysql_error (). '
';
}
Creating table
/* $create = ' CREATE TABLE myTable (
		ID INT UNSIGNED not NULL auto_increment PRIMARY KEY,
		name Varcha R () not NULL
	) ';p rint '
Create ...
";
	
	if (@mysql_query ($create)) {
		print '
created!
';
	} else {
		print '
Can not create error: '. Mysql_error (). '
';
	} Mysql_close ();
Insert data
$insert = ' INSERT into myTable (ID, name) VALUES (12345, "Charles") ";
if (@mysql_query ($insert)) {
		print '
inserted!
';
	} else {
		print '
Can not insert error: '. Mysql_error (). '
';
	} Mysql_close ();

? >
	

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