gistfile1.txt

SET @settingName = "feeMID", @companyId = 1;

SELECT COALESCE(company_setting.value, default_setting.value) AS value
FROM default_setting
LEFT JOIN company_setting
ON company_setting.default_setting_id
WHERE default_setting.name = @settingName
AND company_setting.company_id = @companyId

SET @SettingName = "feeMID", @companyid = 1;

SELECT COALESCE(
(
SELECT cs.value
FROM default_setting ds
INNER JOIN company_setting cs
ON cs.default_setting_id
WHERE cs.company_id = @companyid
AND ds.name = @SettingName
),
(
SELECT ds.value
FROM default_setting ds
INNER JOIN company_setting cs
ON cs.default_setting_id
WHERE cs.company_id = @companyid
AND ds.name = @SettingName
)
) AS value;

SET @SettingName = "test", @companyid = 1;

SELECT COALESCE(
(
SELECT cs.value
FROM company_setting cs
LEFT JOIN default_setting ds
ON cs.default_setting_id = ds.id
WHERE cs.company_id = @companyid
AND ds.name = @SettingName
),
(
SELECT ds.value
FROM default_setting ds
WHERE ds.name = @SettingName
)
) AS value