Concatenating Multiple Rows From a Select Into a Single Line and Generating JSON From a Query [SQL SERVER]

To concatenate multiple rows into one:

SELECT CAST((
    SELECT COLUNA1 + ' - ' COLUNA2 FROM TABELA FOR XML PATH('')
) AS VARCHAR(MAX));

So, to generate JSON from a query:

SELECT '[' + CAST((
    SELECT '{"coluna1":' + COLUNA1 + '","coluna2":"' + COLUNA2 + '"},' FROM TABELA FOR XML PATH('')
) AS VARCHAR(MAX)) + ']';