How to solve this stored procedure issue? - sql-server

Question

I created this stored procedure in SQL Server 2017, and apparently it worked at first but suddenly it just stopped working.
This is supposed to validate whether a car has already entered in a parking lot or not. If it hasn't it creates the row and in the vehicle table and creates the row in vehicle payment table. If this is not the case it just creates the row in in the vehicle payment table and updates the state to (meaning it's currently in).
--table names, fields and variables are in spanish
CREATE TABLE Estacionamiento.Vehiculo
(
id INT IDENTITY (1, 1) NOT NULL
CONSTRAINT PK_Vehiculo_Estacionamiento_id
PRIMARY KEY CLUSTERED (id),
tipoVehiculo INT NOT NULL,
placa NVARCHAR(8) NOT NULL UNIQUE,
CONSTRAINT CHK_Formato_Placa_Vehiculo
CHECK (placa LIKE '[A-Z][A-Z][A-Z]-[0-9][0-9][0-9][0-9]'),
estado BIT NOT NULL
)
GO
--Crear la tabla PagoVehiculo
CREATE TABLE Estacionamiento.PagoVehiculo
(
id INT IDENTITY(1, 1) NOT NULL
CONSTRAINT PK_Vehiculo_PagoVehiculo_id
PRIMARY KEY CLUSTERED (id),
vehiculo INT NOT NULL,
fechaHoraEntrada DATETIME NOT NULL,
fechaHoraSalida DATETIME NOT NULL,
total DECIMAL NOT NULL
)
GO
--The problem is here
CREATE PROCEDURE SP_InsercionVehiculosEntradasSalidas
(#placa NVARCHAR(8),
#tipoVehiculo NVARCHAR(15))
AS
BEGIN TRY
DECLARE #placaVehiculo INT
DECLARE #horaEntrada DATETIME
DECLARE #horaSalida DATETIME
IF NOT EXISTS(SELECT * FROM Estacionamiento.Vehiculo WHERE placa = #placa AND tipoVehiculo = #tipoVehiculo)
BEGIN
INSERT INTO Estacionamiento.Vehiculo (placa, tipoVehiculo, estado)
VALUES (#placa, #tipoVehiculo, 1)
SET #placaVehiculo = (SELECT id FROM Estacionamiento.Vehiculo WHERE placa = #placa)
INSERT INTO Estacionamiento.PagoVehiculo (vehiculo, fechaHoraEntrada, fechaHoraSalida, total)
VALUES (#placaVehiculo, GETDATE(), GETDATE(), 0)
END
ELSE IF EXISTS(SELECT * FROM Estacionamiento.Vehiculo WHERE placa = #placa)
BEGIN
SET #placaVehiculo = (SELECT id FROM Estacionamiento.Vehiculo WHERE placa = #placa)
PRINT(#placaVehiculo)
IF (SELECT estado FROM Estacionamiento.Vehiculo WHERE placa = #placa) = 0
BEGIN
INSERT INTO Estacionamiento.PagoVehiculo (vehiculo, fechaHoraEntrada, fechaHoraSalida, total)
VALUES (#placaVehiculo, GETDATE(), GETDATE(), 0)
UPDATE Estacionamiento.Vehiculo
SET estado = 1
END
ELSE IF (SELECT estado FROM Estacionamiento.Vehiculo WHERE placa = #placa) = 1
BEGIN
UPDATE Estacionamiento.PagoVehiculo
SET fechaHoraSalida = GETDATE()
WHERE vehiculo = #placaVehiculo
AND id = (SELECT MAX(id) FROM Estacionamiento.PagoVehiculo)
SET #horaEntrada = (SELECT MAX(fechaHoraEntrada)
FROM Estacionamiento.PagoVehiculo
WHERE vehiculo = #placaVehiculo)
SET #horaSalida = (SELECT MAX(fechaHoraSalida)
FROM Estacionamiento.PagoVehiculo
WHERE vehiculo = #placaVehiculo)
UPDATE Estacionamiento.Vehiculo
SET estado = 0
UPDATE Estacionamiento.PagoVehiculo
SET total = dbo.Fctn_CalculoPagoVehiculo(#horaEntrada, #horaSalida, #tipoVehiculo)
WHERE vehiculo = #placaVehiculo
AND id = (SELECT MAX(id)
FROM Estacionamiento.PagoVehiculo)
END
END
END TRY
BEGIN CATCH
DECLARE #error INT
SET #error = ##ERROR
RETURN #error
END CATCH
GO
I'm expecting to validate and insert and update when needed.

Answer 1

A few things that I am noticing as I read your proc:
In some places you check for a unique car in the vehiculo table by doing :
WHERE placa = #placa AND tipoVehiculo = #tipoVehiculo
and other places by doing just
WHERE placa = #placa
Be consistent in your code depending on which gives you the unique car
When the car is inserted into PagoVehiculo, you are populating both the entry and exit dates with the current date. While not technically wrong, I would expect the exit date to be null until the car exits. That will help with clarity of the data.
There are many places where you check select *, you can instead select 1, which will perform better
There is no ELSE statement to catch unexpected situations and report and issue.
At one point you are trying to get the id of the pagoVehiculo table for a particular car by doing:
id = (SELECT MAX(id) FROM Estacionamiento.PagoVehiculo)
There is no guaranty that will retrieve the correct car (specially since you could have multiple clients writting to the table at the same time. Add an additional clause to ensure you are pulling data for the right car. something like:
id = (SELECT MAX(id) FROM Estacionamiento.PagoVehiculo where vehiculo = #placaVehiculo)
In terms of what is going on with the proc, My guess is that is either failing silently or it is not falling into the IF or the ELSE IF and thus just skipping the whole thing. I would debug this as follows (after reviewing the comments :
Add and ELSE statement in the main If statement to catch unexpected situations
Add a print statement in the IF section , ELSE If and ELSE sections (something like print ('in IF statement') so that you know which branch is executing (or you can just debug it , if you are familiar with SQL Proc debugging)
Remove the try catch section and see if there is an exception that is being catched and not rethrown for some reason.
Oh and I just saw, tipoVehiculo is defined as INT in the table , but you are passing a NVARCHAR(15) in the proc, which is prob why you have the problem.