Can a user input query in WFA have IF THEN ELSE

Question

Below is my query and when I save it WFA throws the following error.Illegal user input query 'IF '${vfilerName}' != 'vfiler0' THEN
SELECT
vol.name,
array.ip AS 'array.ip'
FROM
storage.vfiler AS vfl,
storage.volume AS vol,
storage.array AS array
WHERE
vol.vfiler_id = vfl.id... HERE is my actual query. IS an  IF THEN ELSE supported or I am doing something wrong.... IF '${vfilerName}' != 'vfiler0' THEN
SELECT
vol.name,
array.ip AS 'array.ip'
FROM
storage.vfiler AS vfl,
storage.volume AS vol,
storage.array AS array
WHERE
vol.vfiler_id = vfl.id
AND vfl.name = '${vfilerName}'
AND vol.array_id = array.id
AND (
array.ip = '${arrayName}'
OR array.name = '${arrayName}'
AND vol.name = '${volName}'
ORDER BY
vol.name DESC
ELSE
SELECT
vol.name AS 'name',
array.ip AS 'array.ip',
array.name AS 'array.name'
FROM
storage.volume AS vol
JOIN
storage.array AS array
ON vol.array_id = array.id
WHERE
array.ip = '${arrayName}'
OR array.name = '${arrayName}'
END IF

Answer 1

Yes you can use IF, but you cannot use Select ..... IF.... Select... ELSE.... SELECT... . It's not a valid SQL statement. If you want many SELECT statements you should use UNION but most of the time you won't need it. I've create a query that uses and it may help you. Take a look at the way I use IF. SELECT
    export_policy.name 'Nome das políticas',
    GROUP_CONCAT(if(rw_rule='sys'
    OR rw_rule='any',
    export_rule.clientmatch,
    null)) 'REGRAS RW',
    GROUP_CONCAT(if((ro_rule='sys'
    OR ro_rule='any')
    AND rw_rule='none',
    export_rule.clientmatch,
    null)) 'Regras RO'
FROM
    cm_storage.export_policy
INNER JOIN
    cm_storage.export_rule
        ON export_policy.id=export_rule.policy_id
JOIN
    cm_storage.vserver
        ON export_policy.vserver_id=vserver.id
WHERE
    vserver.name='${VserverName}'
    AND export_policy.name!='default'
GROUP BY
    export_policy.name You can have some reference of IF usage here: https://dev.mysql.com/doc/refman/5.1/en/control-flow-functions.html#function_if