As the error states, you need to make sure your columns all have valid identifiers (and although COUNT(NOMBRE)
is a valid expression, it is not a valid identifier to name the column in the view).
You can either name it in the view's signature:
CREATE OR REPLACE VIEW emplpersuc (nombre, nombre_count) AS
SELECT s.NOMBRE,
COUNT(s.NOMBRE)
FROM VENTA v
JOIN SUCURSAL s
ON SUCURSAL_CODIGO_SUCURSAL=CODIGO_SUCURSAL
GROUP BY s.NOMBRE
ORDER BY COUNT(s.NOMBRE) DESC;
or with a column alias in the query:
CREATE OR REPLACE VIEW emplpersuc AS
SELECT s.NOMBRE,
COUNT(s.NOMBRE) AS nombre_count
FROM VENTA v
JOIN SUCURSAL s
ON SUCURSAL_CODIGO_SUCURSAL=CODIGO_SUCURSAL
GROUP BY s.NOMBRE
ORDER BY COUNT(s.NOMBRE) DESC;