SQl notes

SELECT COUNT(DISTINCT user_id) AS 'enrolments',
  COUNT(CASE
        WHEN strftime("%m", cancel_date) = '03'
        THEN user_id
  END) AS 'march_cancellations',
  ROUND(100.0 * COUNT(CASE
        WHEN strftime("%m", cancel_date) = '03'
        THEN user_id
  END) / COUNT(DISTINCT user_id)) AS 'churn_rate'
FROM pro_users
WHERE signup_date < '2017-04-01'
 AND (
    (cancel_date IS NULL) OR
    (cancel_date > '2017-03-01')
  );

CREATE TYPE LocationTableType
   AS TABLE
      ( LocationName VARCHAR(50)
      , CostRate INT );
GO
/* Create a procedure to receive data for the table-valued parameter. */
CREATE PROCEDURE dbo. usp_InsertProductionLocation
   @TVP LocationTableType READONLY
      AS
      SET NOCOUNT ON
      INSERT INTO AdventureWorks2012.Production.Location
         (
            Name
            , CostRate
            , Availability
            , ModifiedDate
         )
      SELECT *, 0, GETDATE()
      FROM @TVP;
GO
/* Declare a variable that references the type. */
DECLARE @LocationTVP AS LocationTableType;
/* Add data to the table variable. */
INSERT INTO @LocationTVP (LocationName, CostRate)
   SELECT Name, 0.00
   FROM AdventureWorks2012.Person.StateProvince;

/* Pass the table variable data to a stored procedure. */
EXEC usp_InsertProductionLocation @LocationTVP;