like operator with variable string - sql

Question

i am using LIKE operator in sql but is show some error.here is my code
<?php
header('Access-Control-Allow-Origin: *');
$con=mysqli_connect("url","xxxx","password","xxxx");
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
exit();
}
$callback =$_GET['callback'];
DECLARE #alpha nchar(1)
SET #alpha = 'A'
$result= mysqli_query($con,"SELECT * FROM demo WHERE Name LIKE #alpha + '%'");
$var= array();
while($row = mysqli_fetch_assoc($result))
{
$var[]=$row;
}
echo $callback."(".json_encode($var).")";
mysqli_close($con);
?>
it works properly when i am using it without alpha i.e when i give string directly.but when i am useing with vaiable it shows an error "Unexpected token <"

Answer 1

I am not a PHP expert, so am not sure of the syntaxes...but you can try the following:
SET #alpha = "A"
$result= mysqli_query($con,"SELECT * FROM demo WHERE Name LIKE '" + #alpha + "%'");
i.e. use the PHP strings within double inverted commas (") and the SQL strings within single inverted commas (')
Also, changing the second line as above should result in the SQL query:
SELECT * FROM demo WHERE Name LIKE 'A%' which is what I think you want. I am not sure if using the variable name within the string will result in getting its value or embed it as it is in the query.