Query extremely slow - mysql

Question

I am running the below query, but its extremeely slow. Dows anyone have any advice on how I can optimize it to improve performance.
The main user table only has 2700 row.
The query is:
SELECT
(
SELECT
core_org_chart.translation
FROM
core_org_chart
WHERE
(
core_org_chart.id_dir = t1.idOrg
)
) AS region,
(
SELECT
core_org_chart.translation
FROM
core_org_chart
WHERE
(
core_org_chart.id_dir = t2.idOrg
)
) AS level1,
(
SELECT
core_org_chart.translation
FROM
core_org_chart
WHERE
(
core_org_chart.id_dir = t3.idOrg
)
) AS level2,
(
SELECT
core_org_chart.translation
FROM
core_org_chart
WHERE
(
core_org_chart.id_dir = t4.idOrg
)
) AS level3,
core_user.firstname AS firstname,
core_user.lastname AS lastname,
core_user.email AS email,
core_user.register_date AS register_date,
core_user.lastenter AS lastenter,
(
SELECT
core_field_son.translation
FROM
(
core_field_son
JOIN core_field_userentry ON (
(
core_field_userentry.user_entry = core_field_son.idSon
)
)
)
WHERE
(
(
core_field_userentry.id_user = core_user.idst
)
AND (
core_field_userentry.id_common = 4
)
)
) AS Gender,
(
SELECT
core_field_son.translation
FROM
(
core_field_son
JOIN core_field_userentry ON (
(
core_field_userentry.user_entry = core_field_son.idSon
)
)
)
WHERE
(
(
core_field_userentry.id_user = core_user.idst
)
AND (
core_field_userentry.id_common = 6
)
)
) AS Race,
IF (
(core_user.valid = 1),
'Active',
'Suspended'
) AS UserStatus,
(
SELECT
jet_designations.designation
FROM
jet_designations
WHERE
(
jet_designations.id = core_user.designation
)
) AS UserDesignation,
(
SELECT
jet_designations.designation
FROM
jet_designations
WHERE
(
jet_designations.id = core_user.reports_to
)
) AS Manager
FROM
(
(
(
(
(
core_org_chart_tree t1
LEFT JOIN core_org_chart_tree t2 ON (
(
t2.idParent = t1.idOrg
)
)
)
LEFT JOIN core_org_chart_tree t3 ON (
(
t3.idParent = t2.idOrg
)
)
)
LEFT JOIN core_org_chart_tree t4 ON (
(
t4.idParent = t3.idOrg
)
)
)
JOIN core_group_members ON (
(
core_group_members.idst =
IF (
isnull(t2.idOrg),
t1.idst_ocd,
IF (
isnull(t3.idOrg),
t2.idst_ocd,
IF (
isnull(t4.idOrg),
t3.idst_ocd,
t4.idst_ocd
)
)
)
)
)
)
JOIN core_user ON (
(
core_user.idst = core_group_members.idstMember
)
)
)
WHERE
(t1.lev = 1)

Answer 1

you are using multiple queries in one, joining them will improve performance.