Difference between revisions of "Nullable Dates"
(New page: In AbleCommerce 7.0.0 through AbleCommerce 7.0.7, many of our objects had DateTime properties that were nullable in the database. In these versions we would translate null into the value ...) |
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| − | In AbleCommerce 7.0.0 through AbleCommerce 7.0.7, many of our objects had DateTime properties that were nullable in the database. In these versions we would translate null into the value System.DateTime.MinValue when reading the records. When making business logic decisions the DateTime property would need to | + | In AbleCommerce 7.0.0 through AbleCommerce 7.0.7, many of our objects had DateTime properties that were nullable in the database. In these versions we would translate null into the value System.DateTime.MinValue when reading the records. When making business logic decisions the DateTime property would need to be checked against DateTime.MinValue to see if it was present. |
In AbleCommerce Gold the behavior changes slightly. Instead of translating null dates, our DateTime properties are nullable. This means the property can either be null or it can have a value. In order to use these DateTime properties you must be sure to factor in the possibility that the value does not exist in the database. In these cases you must decide how to handle that condition. | In AbleCommerce Gold the behavior changes slightly. Instead of translating null dates, our DateTime properties are nullable. This means the property can either be null or it can have a value. In order to use these DateTime properties you must be sure to factor in the possibility that the value does not exist in the database. In these cases you must decide how to handle that condition. | ||
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| User || LastLockoutDate || The user has never been locked out. | | User || LastLockoutDate || The user has never been locked out. | ||
|} | |} | ||
| + | |||
| + | ==Working with Nullable Dates== | ||
| + | |||
| + | In customizing code with these properties you may notice from Intellisense that nullable dates act a little different from regular DateTime values. There are two different ways to decide if a DateTime has a value: | ||
| + | |||
| + | <code>if (Coupon.StartDate.HasValue)</code> | ||
| + | |||
| + | OR | ||
| + | |||
| + | <code>if (Coupon.StartDate != null)</code> | ||
| + | |||
| + | And when accessing the DateTime you need to use the Value property: | ||
| + | |||
| + | <code>Coupon.StartDate.Value</code> | ||
Latest revision as of 16:13, 17 October 2012
In AbleCommerce 7.0.0 through AbleCommerce 7.0.7, many of our objects had DateTime properties that were nullable in the database. In these versions we would translate null into the value System.DateTime.MinValue when reading the records. When making business logic decisions the DateTime property would need to be checked against DateTime.MinValue to see if it was present.
In AbleCommerce Gold the behavior changes slightly. Instead of translating null dates, our DateTime properties are nullable. This means the property can either be null or it can have a value. In order to use these DateTime properties you must be sure to factor in the possibility that the value does not exist in the database. In these cases you must decide how to handle that condition.
A list of the properties that are nullable are below:
| CLASS | PROPERTY | SIGNIFICANCE OF NULL |
|---|---|---|
| Coupon | StartDate | The coupon has no restriction on when it starts to be valid. |
| Coupon | EndDate | The coupon has no restriction on when it ceases to be valid. |
| EmailList | LastSendDate | The email list has never been sent. |
| EmailListUser | LastSendDate | The email list has never been sent to this list member. |
| OrderItemDigitalGood | ActivationDate | The digital good has not been activated. |
| OrderItemDigitalGood | DownloadDate | The digital good has not been downloaded. |
| OrderShipment | ShipDate | The order shipment has not been shipped. |
| Subscription | ExpirationDate | The subscription has no expiration. |
| Payment | CompletedDate | The payment has not yet been completed. |
| Special | StartDate | The special has no restriction on when it starts to be active. |
| Special | EndDate | The special has no restriction on when it ceases to be active. |
| Redirect | LastVisitedDate | The redirect has never been visited. |
| Currency | LastUpdate | The exchange rate for the currency has never been updated. |
| User | AffiliateReferralDate | The user has not been referred by an affiliate. |
| User | LastActivityDate | The user has never browsed the site. |
| User | LastLoginDate | The user has never logged in. |
| User | LastPasswordChangedDate | The user has never changed the password. |
| User | LastLockoutDate | The user has never been locked out. |
Working with Nullable Dates
In customizing code with these properties you may notice from Intellisense that nullable dates act a little different from regular DateTime values. There are two different ways to decide if a DateTime has a value:
if (Coupon.StartDate.HasValue)
OR
if (Coupon.StartDate != null)
And when accessing the DateTime you need to use the Value property:
Coupon.StartDate.Value
