A tip: Updating Data in SharePoint 2010 using REST API
- by Sahil Malik
SharePoint 2010 Training: more information
Here is a little tip that will save you hours of head scratching. See there are two ways to update data in SharePoint using REST based API. A PUT request is used to update an entire entity. If no values are specified for fields in the entity, the fields will be set to default values. A MERGE request is used to update only those field values that have changed. Any fields that are not specified by the operation will remain set to their current value. Now, sit back and think about it. You are going to update the entire entity! Hmm. Which means, you need to a) specify every column value, and b) ensure that the read only values match what was supplied to you. What a pain in the donkey! So 99/100 times, a PUT request will give you a HTTP 500 internal server error occurred, which is just so helpful.
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