PHP and MYSql connection and query

1. Connect to the database
1. mysql_connect: Open the MySQL link

mysql_connect('host', 'username', 'password')

2. mysql_select_db: open a database
mysql_select_db('database name', $ link identifier character) //If the link identifier is not filled in, it will default to the last opened connection

3. mysql_query("set names 'GBK'") solves the Chinese garbled problem;

　mysql_query("set names 'encoding (utf8 or GBK) ' ") //UTF8 cannot have "-"

2. Query data

1. mysql_query (SQL statement, connection identifier);

$sql="Select * FROM Test "
$result=mysql_query($sql ) //The connection identifier defaults to the last opened link

//Get error information

$result=@mysql_query($sql) or die(mysql_error())

2. Get the query results

　a , mysql_fetch_row($result);

　　$row=mysql_fetch_row($result);
　　 echo $row[0];

b、 mysql_fetch_array($result); sult);
echo $ row[0];
echo $row['key'];


Explanation: The functions of mysql_fetch_array and mysql_fetch_row are basically the same, except that in addition to using the offset starting from 0 as an index, it can also use the domain name as an index.
Value returns all field values ​​of the next row and saves them in an array. Returns false if there is no row.