MySQL, Concatenate two columns

Question

There are two columns in a MySQL table: SUBJECT and YEAR.

I want to generate an alphanumeric unique number which holds the concatenated da

Answer 1

In php, we have two option to concatenate table columns.

First Option using Query

In query, CONCAT keyword used to concatenate two columns

SELECT CONCAT(`SUBJECT`,'_', `YEAR`) AS subject_year FROM `table_name`;

Second Option using symbol ( . )

After fetch the data from database table, assign the values to variable, then using ( . ) Symbol and concatenate the values

$subject = $row['SUBJECT'];
$year = $row['YEAR'];
$subject_year = $subject . "_" . $year;

Instead of underscore( _ ) , we will use the spaces, comma, letters,numbers..etc

Answer 2

You can use php built in CONCAT() for this.

SELECT CONCAT(`name`, ' ', `email`) as password_email FROM `table`;

change filed name as your requirement

then the result is

and if you want to concat same filed using other field which same then

SELECT filed1 as category,filed2 as item, GROUP_CONCAT(CAST(filed2 as CHAR)) as item_name FROM `table` group by filed1 

then this is output

Answer 3

You can use the CONCAT function like this:

SELECT CONCAT(`SUBJECT`, ' ', `YEAR`) FROM `table`

Update:

To get that result you can try this:

SET @rn := 0;

SELECT CONCAT(`SUBJECT`,'-',`YEAR`,'-',LPAD(@rn := @rn+1,3,'0'))
FROM `table`

Answer 4

$crud->set_relation('id','students','{first_name} {last_name}');
$crud->display_as('student_id','Students Name');