MySQL

PHP

Web Technology

Logging in to Command Line

• Start -> Programs -> AppServ -> MySQL Command Line Client

• Enter Password, then you’ll be working as root.

Browsing Databases

• Some useful commands to begin with– status;– show databases; - show all databases– use <database_name>; – show tables;– desc <table_name>– create database <database_name>

• Create a new database

CREATE DATABASE webtech

Create a User

• It is a good idea to create a username to manage tables in new created database

• Proper privileges can be granted to a particular user so that only a user who has right access can manage the table

GRANT <previledge> [(col1, col2, … colN)] ON database.[table] TO user@host IDENTIFIED BY 'passwd';

GRANT select ON webtech.tct_phone TO tct@localhost IDENTIFIED BY ‘tct';

MySQL Privilege Scope

Create a Table

CREATE TABLE tct_phone (STD_ID INT NOT NULL AUTO_INCREMENT PRIMARY KEY,STD_FNAME VARCHAR( 64 ) NOT NULL ,STD_LNAME VARCHAR( 64 ) NOT NULL ,STD_PHONE VARCHAR( 12 ) NOT NULL

);

CREATE TABLE <table_name> (column_name1 <col_type> ….., ............

)

SELECT Statements

• Select all records (rows) from a table

• Select some columns of all records from a table

SELECT * FROM <table_name>;

SELECT col1, col2,….colx FROM <table_name>;

SELECT * FROM tct_phone;

SELECT std_id, std_fname, std_lname FROM tct_phone;

SELECT Statements (cont.)

• Select some records from a table

• WHERE clause could be any boolean expression

• ORDER BY clause (either asc or desc)

SELECT * FROM tct_phone WHERE std_id > 20;

SELECT * FROM <table_name> WHERE <condition>;

SELECT * FROM tct_phone WHERE std_id > 20 and std_fname like ‘sor%’;

SELECT * FROM tct_phone WHERE std_id > 20 and std_fname like ‘sor%’ ORDER BY std_fname desc;

Connecting to Database Using PHP

$hostname = “localhost”;$dbUser = “tct”;$dbPass = “tct”;$conn = mysql_connect($hostname, $db_user, $password) or die(“Cannot open connection”);

mysql_connect(HOSTNAME, USER, PASSWD);

Selecting a Database

mysql_select_db(“webtech”, $conn ) or die ("Cannot open database");

mysql_select_db(DATABASE, CONNECTION);

Making Query

• Making query to opened database

• Checking the number of fields from the query

• Checking the number of records we get

mysql_query($query);

mysql_num_fields($result)

mysql_affected_rows()

How to Retrieve the Records

• There are a number of ways to get them:$name_row = mysql_fetch_row($result)

$row = mysql_fetch_object($result)

$row = mysql_fetch_array($result)

while ($name_row = mysql_fetch_row($result)) print("$name_row[0] $name_row[1] $name_row[2] <BR>\n");

while ($row = mysql_fetch_object($result)) print("$row->std_id -> $row->std_fname $row->std_lname<BR>\n");

while ($row = mysql_fetch_array($result)) print($row[std_id '].$row[std_fname '].$row[std_lname'] <BR>\n");

Example Code$conn = mysql_connect(‘localhost’, ‘tct’, ‘tct’) or die("Cannot open connection");mysql_select_db(“webtech”, $conn ) or die ("Cannot open database");mysql_db_query("tct_phone","SET NAMES utf8");//Use UTF8 for Thai font

$query = "select * from tct_phone";

$result = mysql_query($query);$num_fields = mysql_num_fields($result);

echo "<TABLE border=1>";echo "<TR>";for($i=0; $i < $num_fields; $i++) echo "<TH>".mysql_field_name($result, $i)."</TH>";echo "</TR>";while ($name_row = mysql_fetch_row($result)) {

echo "<TR>";for($i=0; $i < $num_fields; $i++) print("<TD>$name_row[$i] </TD>");echo "</TR>";

}echo "</table>";