The FORMAT function displays the number x by using commas as thousands delimiters, so that its format becomes ‘#,###,###.#####’ and performs rounding after the decimal point to express as many as dec digits after it. The return value is a string type.
FORMAT ( x , dec )
SELECT FORMAT(12000.123456,3), FORMAT(12000.123456,0);
format(12000.123456, 3) format(12000.123456, 0)
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'12,000.123' '12,000'