handle transactions on paypal webhook

src/Sql/dbo/Stored Procedures/Transaction_ReadByGatewayId.sql

@@ -0,0 +1,15 @@
+CREATE PROCEDURE [dbo].[Transaction_ReadByGatewayId]
+    @Gateway TINYINT,
+    @GatewayId VARCHAR(50)
+AS
+BEGIN
+    SET NOCOUNT ON
+
+    SELECT
+        *
+    FROM
+        [dbo].[TransactionView]
+    WHERE
+        [Gateway] = @Gateway
+        AND [GatewayId] = @GatewayId
+END

src/Sql/dbo/Tables/Transaction.sql

@@ -18,7 +18,7 @@
 
 
 GO
-CREATE NONCLUSTERED INDEX [IX_Transaction_Gateway_GatewayId]
+CREATE UNIQUE NONCLUSTERED INDEX [IX_Transaction_Gateway_GatewayId]
     ON [dbo].[Transaction]([Gateway] ASC, [GatewayId] ASC);