php connect mysql database operation class

This is a relatively full mysql operation Oh, yesterday wrote a simple link mysql database code, relative to this, that is the easiest, this is a data query, update, delete, and other operations .
* /

class mysql {

private $ db_host; / / database host
private $ db_user; / / database user name
private $ db_pwd; / / Database password
private $ db_database; / / database name
private $ conn; / / database connection ID;
private $ sql; / / sql statement executed
private $ result; // query resource identifier
private $ coding; / / Database coding, gbk, utf8, gb2312
private $ show_error = true; / / Debugging local use, printing error

/ **
* Constructor
*
* @access public
* @parameter string $ db_host database host
* @parameter string $ db_user database user name
* @parameter string $ db_pwd database password
* @parameter string $ db_database database name
* @parameter string $ coding
* @return void
* /
public function __construct ($ db_host, $ db_user, $ db_pwd, $ db_database, $ coding) {
$ this-> db_host = $ db_host;
$ this-> db_user = $ db_user;
$ this-> db_pwd = $ db_pwd;
$ this-> db_database = $ db_database;
$ this-> coding = $ coding;
$ this-> connect ();
}

/ **
* Link database
*
* @access private
* @return void
* /
private function connect () {

$ this-> conn = @mysql_connect ($ this-> db_host, $ this-> db_user, $ this-> db_pwd);
if (! $ this-> conn) {
// show_error is on, printing error
if ($ this-> show_error) {
$ this-> show_error ('error message: link database failed!');
}
}

if (! @ mysql_select_db ($ this-> db_database, $ this-> conn)) {
// failed to open the database
if ($ this-> show_error) {
$ this-> show_error ('error message: open the database failed!');
}
}

if (! @ mysql_query ("set names $ this-> coding")) {
// set the encoding failed
if ($ this-> show_error) {
$ this-> show_error ('error message: set the encoding failed!');
}
}
}

/ **
* Executable query to add modify delete any sql statement
*
* @access public
* @parameter string $ sql sql statement
@return resource Resource identifier
* /
public function query ($ sql) {
$ this-> sql = $ sql;
$ result = mysql_query ($ this-> sql, $ this-> conn);
if (! $ result) {
// query execution failed, printing error
$ this-> show_error ("Wrong sql statement:", $ this-> sql);
} else {
// return resource identifier
return $ this-> result = $ result;
}
}

/ **
* Query all the databases in the mysql server
*
* @access public
* @return void
* /
public function show_databases () {
$ this-> query ("show databases");
// Print the total number of databases
echo "Existing database:". mysql_num_rows ($ this-> result);
echo "<br />";
$ i = 1;
// Loop out the name of each database
while ($ row = mysql_fetch_array ($ this-> result)) {
echo "$ i $ row [database]". "<br />";
$ i ++;
}
}

/ **
* Query all the table name under the database
*
* @access public
* @return void
* /
public function show_tables () {
$ this-> query ("show tables");
// Print the total number of tables
echo "Database {$ this-> db_database}" mysql_num_rows ($ this-> result). "Sheet:";
echo "<br />";
// Construct an array index, loop out all the database table name
$ column_name = "tables_in_". $ this-> db_database;
$ i = 1;
// Loop out the name of each table
while ($ row = mysql_fetch_array ($ this-> result)) {
echo "$ i $ row [$ column_name]". "<br />";
$ i ++;
}
}

/ **
Get recordsets, get array - index and correlation
*
* @access public
* @return void
* /
public function fetch_array () {
return mysql_fetch_array ($ this-> result);
}

/ **
* Simplify select query
*
* @access public
* @parameter string $ table table name
* @parameter string $ field field name
* @return resource
* /
public function findall ($ table, $ field = '*') {
return $ this-> query ("select $ field from $ table");
}

/ **
* Simplified delete query
*
* @access public
* @parameter string $ table table name
* @parameter string $ condition Query conditions
* @return resource
* /
public function delete ($ table, $ condition) {
return $ this-> query ("delete from $ table where $ condition");
}

/ **
* Simplified insert insert statement
*
* @access public
* @parameter string $ table table name
* @parameter string $ field field name
* @parameter string $ value Insert value
* @return resource
* /
public function insert ($ table, $ field, $ value) {
return $ this-> query ("insert into $ table ($ field) values ​​('$ value')");
}

/ **
* Simplify the update insert statement
*
* @access public
* @parameter string $ table table name
* @parameter string $ update_content Updated content
* @parameter string $ condition condition
* @return resource
* /
public function update ($ table, $ update_content, $ condition) {
return $ this-> query ("update $ table set $ update_content where $ condition");
}

/ **
* Get the ID generated by the previous insert operation
*
* @access public
* @return integer
* /
public function insert_id () {
return mysql_insert_id ();
}

/ **
* Calculate the result set number
*
* @access public
* @return integer
* /
public function num_rows () {
return mysql_num_rows ($ this-> result);
}

/ **
* Query the number of fields and field information
*
* @access public
* @parameter string $ table table name
* @return void
* /
public function num_fields ($ table) {
$ this-> query ("select * from $ table");
echo "<br />";
// print the number of fields
echo "Number of fields:". $ total = mysql_num_fields ($ this-> result);
echo "<pre>";
// The mysql_fetch_field () function takes the column information from the result set and returns it as an object.
for ($ i = 0; $ i <$ total; $ i ++) {
print_r (mysql_fetch_field ($ this-> result, $ i));
}
echo "</ pre>";
echo "<br />";
}

/ **
* Output sql statement error message
*
* @access public
* @parameter string $ message message
* @return void
* /
public function show_error ($ message = '', $ sql = '') {
echo "<fieldset>";
echo "<legend> error message: </ legend> <br />";
echo "<div style = 'font-size: 14px; clear: both; font-family: verdana, arial, helvetica, sans-serif;'>";
// Cause of printing error
echo "Cause of the error:". mysql_error (). "<br /> <br />";
// print error message
// mysql_error () function returns the text of a mysql operation error message.
echo "<div style = 'height: 20px; background: # ff0000; border: 1px # ff0000 solid'>";
echo "<font color = 'white'>". $ message. "</ font>";
echo "</ div>";
// Print error sql statement
echo "<font color = 'red'> <pre>". $ sql. "</ pre> </ font>";
echo "</ div>";
echo "</ fieldset>";
}
}
//Instructions

$ mysql = new mysql ($ dbhost, $ dbuser, $ dbpwd, $ dbname, $ coding);
?>