Example
One type of JOIN that is less known, is the FULL JOIN.
(Note: FULL JOIN is not supported by MySQL as per 2016)
A FULL OUTER JOIN returns all rows from the left table, and all rows from the right table.
If there are rows in the left table that do not have matches in the right table, or if there are rows in right table that do not have matches in the left table, then those rows will be listed, too.
Example 1 :
SELECT * FROM Table1
FULL JOIN Table2
ON 1 = 2
Example 2:
SELECT
COALESCE(T_Budget.Year, tYear.Year) AS RPT_BudgetInYear
,COALESCE(T_Budget.Value, 0.0) AS RPT_Value
FROM T_Budget
FULL JOIN tfu_RPT_All_CreateYearInterval(@budget_year_from, @budget_year_to) AS tYear
ON tYear.Year = T_Budget.Year
Note that if you're using soft-deletes, you'll have to check the soft-delete status again in the WHERE-clause (because FULL JOIN behaves kind-of like a UNION);
It's easy to overlook this little fact, since you put AP_SoftDeleteStatus = 1 in the join clause.
Also, if you are doing a FULL JOIN, you'll usually have to allow NULL in the WHERE-clause; forgetting to allow NULL on a value will have the same effects as an INNER join, which is something you don't want if you're doing a FULL JOIN.
Example:
SELECT
T_AccountPlan.AP_UID
,T_AccountPlan.AP_Code
,T_AccountPlan.AP_Lang_EN
,T_BudgetPositions.BUP_Budget
,T_BudgetPositions.BUP_UID
,T_BudgetPositions.BUP_Jahr
FROM T_BudgetPositions
FULL JOIN T_AccountPlan
ON T_AccountPlan.AP_UID = T_BudgetPositions.BUP_AP_UID
AND T_AccountPlan.AP_SoftDeleteStatus = 1
WHERE (1=1)
AND (T_BudgetPositions.BUP_SoftDeleteStatus = 1 OR T_BudgetPositions.BUP_SoftDeleteStatus IS NULL)
AND (T_AccountPlan.AP_SoftDeleteStatus = 1 OR T_AccountPlan.AP_SoftDeleteStatus IS NULL)
