I'm porting one of my apps that uses MySQL to Android with SQLite database.Now i'm confronted to custom functions that are not supported by SQLite. Erel said here that you can create custom function by rebuilding the engine. How can i do it ? I have 3 main functions that i cannot simply implement in my sqlite queries listed below. How can i achieve this ?
1.
2.
3.
These Ones...
1.
B4X:
BEGIN
DECLARE n int;
SELECT (DATEDIFF(E, S)*(3600*24))+(TIME_TO_SEC(E) - TIME_TO_SEC(S)) INTO n;
RETURN n;
END2.
B4X:
BEGIN
DECLARE n int;
if(S<=S0 AND S0<=E0 AND E0<=E) THEN
SELECT (DATEDIFF(E0, S0)*(3600*24))+(TIME_TO_SEC(E0) - TIME_TO_SEC(S0)) INTO n;
elseif(S0<=S AND S<=E AND E<=E0) THEN
SELECT (DATEDIFF(E, S)*(3600*24))+(TIME_TO_SEC(E) - TIME_TO_SEC(S)) INTO n;
elseif(S<=S0 AND S0<=E AND E<=E0) THEN
SELECT (DATEDIFF(E, S0)*(3600*24))+(TIME_TO_SEC(E) - TIME_TO_SEC(S0)) INTO n;
elseif(S0<=S AND S<=E0 AND E0<=E) THEN
SELECT (DATEDIFF(E0, S)*(3600*24))+(TIME_TO_SEC(E0) - TIME_TO_SEC(S)) INTO n;
else SELECT 0 INTO n;
END IF;
RETURN n;
END
B4X:
BEGIN
DECLARE n int;
DECLARE n2 int;
DECLARE n3 int;
DECLARE res int;
if(S<=S0 AND S0<=E0 AND E0<=E) THEN
SELECT (DATEDIFF(E0, S0)*(3600*24))+(TIME_TO_SEC(E0) - TIME_TO_SEC(S0)) INTO n;
elseif(S0<=S AND S<=E AND E<=E0) THEN
SELECT (DATEDIFF(E, S)*(3600*24))+(TIME_TO_SEC(E) - TIME_TO_SEC(S)) INTO n;
elseif(S<=S0 AND S0<=E AND E<=E0) THEN
SELECT (DATEDIFF(E, S0)*(3600*24))+(TIME_TO_SEC(E) - TIME_TO_SEC(S0)) INTO n;
elseif(S0<=S AND S<=E0 AND E0<=E) THEN
SELECT (DATEDIFF(E0, S)*(3600*24))+(TIME_TO_SEC(E0) - TIME_TO_SEC(S)) INTO n;
else SELECT 0 INTO n;
END IF;
SELECT n+(tol*60) INTO n2;
SELECT (DATEDIFF(E, S)*(3600*24))+(TIME_TO_SEC(E) - TIME_TO_SEC(S)) INTO n3;
IF(n2>=n3) THEN SELECT n3 INTO res;
ELSE SELECT n2 INTO res;
END IF;
RETURN res;
ENDThese Ones...