Adding new column with static value to a select query result [duplicate] - php

Question

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add extra column to sql query result with constant value
(2 answers)
Closed 5 months ago.
I want to know what is the best approach if I want to perform select query to MySQL database and then add a new column to the result array which will be exported to a file at later time?
To clarify the process, assume the table have the following data:
id name lastname email
1 john doe example#example.com
2 jane doe example2#example2.com
if I perform the following select query :
$query = "SELECT * from table_name";
$result = mysqli_query($conn, $query);
I get the previous result , and then I want to add a new column to it with static value for all the rows like the following:
Important note: I want to add the column to the returned result not to the database ,because this result is written into a file at a later time.
const_value id name lastname email
samevalue 1 john doe example#example.com
samevalue 2 jane doe example2#example2.com
currently I'm doing this using PHP:
while($row = mysqli_fetch_assoc($result))
{
array_unshift($row , 'samevalue');
}
So is there an easy method of doing this in php or in MySQL during the query ?

Answer 1

You can do that in the original query if that makes sense to your process like this
SELECT 'SameValue' as const_value, id, lastname, email from table_name;
If you really want to do it in PHP then something like this
while($row = mysqli_fetch_assoc($result))
{
$row['const_value'] = 'SameValue';
. . . your other code
}
Or if you want to keep all the rows for later processing
$rows = [];
while($row = mysqli_fetch_assoc($result))
{
$row['const_value'] = 'SameValue';
$rows[] = $row
}