MS SQL Server Interview Question:

PHP ODBC - How To Create an Identity Column?

Submitted by: Administrator

Many tables require an ID column to assign a unique ID number for each row in the table. For example, if you have a table to hold forum member profiles, you need an ID number to identify each member. To allow SQL Server to automatically assign a new ID number for each new record, you can define the ID column with IDENTITY attribute as shown in the following sample script:

<?php
$con = odbc_connect('ggl_SQL_SERVER','sa','GlobalGuideLine');

$sql = "CREATE TABLE ggl_users ("
. " id INTEGER IDENTITY NOT NULL"
. ", name VARCHAR(80) NOT NULL"
. ", email VARCHAR(80)"
. ", time DATETIME"
. ")";
$res = odbc_exec($con, $sql);
if (!$res) {
print("Table creation failed with error: ");
print(odbc_error($con).": ".odbc_errormsg($con)." ");
} else {
print("Table ggl_users created. ");
}

odbc_close($con);
?>

If you run this script, a new table will be created with ID column defined as an identity column. It value will be auto-assigned each time a new record is inserted with an auto-incremented number. The sample script below inserts two records with ID values assigned by SQL Server:

If you run this script, you will get something
Submitted by: Administrator