Mysql 查询存储过程

Question

i have got access to a view of a datatable (mysql 8) which has the following values:

Values DB

now I tried to write an mysql query to fill up the Null values with the last value, because our visualisation tool cannot use null values and the lines in the graph will disappear.

SELECT UTCTIME,
case when Flammtemperatur1 is NULL then
@vorheriger_wert_Flammtemperatur1
else
@vorheriger_wert_Flammtemperatur1 := Flammtemperatur1
end as Flammtemperatur_1,
case when Flammtemperatur2 is NULL then
@vorheriger_wert_Flammtemperatur2
else
@vorheriger_wert_Flammtemperatur2 := Flammtemperatur2
end as Flammtemperatur_2,
case when Rauchgasventilator is NULL then
@vorheriger_wert_Rauchgasventilator
else
@vorheriger_wert_Rauchgasventilator := Rauchgasventilator
end as Rauchgasventilator_,
case when Rezirkulation is NULL then
@vorheriger_wert_Rezirkulation
else
@vorheriger_wert_Rezirkulation := Rezirkulation
end as FRezirkulation_
FROM pivot_test
order by utctime asc

That works fine, but i need to save this in a view or stored procedure, so that our tool can have access to it. Views are not possible because of the session variables. Can someone please help me creating a Stored procedure for my problem? I have never written a SP before.

Thanks!

Result

Answer 1

CREATE PROCEDURE XXXXXName @Flammtemperatur1 DECIMAL (3,2), @Flammtemperatur2 DECIMAL (3,2), @Rauchgasventilator DECIMAL (3,2),@Rezirkulation DECIMAL (3,2) AS SELECT UTCTIME, case when Flammtemperatur1 is NULL then @vorheriger_wert_Flammtemperatur1 else @vorheriger_wert_Flammtemperatur1:= Flammtemperatur1 end as Flammtemperatur_1, case when Flammtemperatur2 is NULL then @vorheriger_wert_Flammtemperatur2 else @vorheriger_wert_Flammtemperatur2:= Flammtemperatur2 end as Flammtemperatur_2, case when Rauchgasventilator is NULL then @vorheriger_wert_Rauchgasventilator else @vorheriger_wert_Rauchgasventilator:= Rauchgasventilator end as Rauchgasventilator_, case when Rezirkulation is NULL then @vorheriger_wert_Rezirkulation else @vorheriger_wert_Rezirkulation:= Rezirkulation end as FRezirkulation_ FROM pivot_test order by utctime asc