如何使用mysql将一个表中的所有列集成到另一个表的一列中

Question

table 1: employee

name| mobile| location
alex| 123   | australia
john| 456   | paris
kohl| 678   | australia

table 2:employment

id|location |data
1 |australia|[{"name":"alex","mobile":"123"},{"name":"kohl","mobile":"678"}]
2 |paris    |[{"name":"john","mobile":"456"}]

i have two tables named "employee" and "employment". How can i get all the column values of employee table into one column of employment table as shown in table 2. I am new to SQL querying. I honestly don't have any idea on how to proceed. Any pointers and suggestions are appreciated.

Answer 1

You can use the following solution using CONCAT and GROUP_CONCAT to get this result:

SELECT location, CONCAT("[", GROUP_CONCAT(CONCAT('{"name":"', name, '","mobile":"', mobile, '"}')), "]") AS data
FROM employee
GROUP BY location

demo: http://sqlfiddle.com/#!9/ab25ee/2/0

To JOIN the employee table with the employment you can use the following solution:

SELECT employment.id, employment.location, CONCAT("[", GROUP_CONCAT(CONCAT('{"name":"', name, '","mobile":"', mobile, '"}')), "]") AS data 
FROM employment INNER JOIN employee ON employment.location = employee.location 
GROUP BY id, location

demo: http://sqlfiddle.com/#!9/12f9c9/1/0