Azure Table Storage InsertOrMerge

Question

I have an Azure Table Storage that contains some data. I need to update one single property for all records in the table. I know the partition key and rowkey for each item. However might be so that I have new items in my CSV file.

What I need to do is:

if an item is found in the table storage based on ParitionKey and RowKey I want to update one single property: Name.
if an item is not found in the table it must be inserted but I have more properties that need to be filled: Name, Email, Address

I am trying to use InsertOrMerge but I got an Etag exception and how can I set up more properties if the item is not found and an insert will be required?

        CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);

        CloudTableClient cloudTableClient = storageAccount.CreateCloudTableClient();

        CloudTable ct = cloudTableClient.GetTableReference("mytable");



             var item = new Item()
             {
                 PartitionKey = "PARTITIONID",
                 RowKey = "ROWID",                
                 Name = "DEMO",                     
             };

        TableOperation to = TableOperation.Merge(code);

        var result = await ct.ExecuteAsync(to);

Unfortunately, you also have to retrieve all items and only then update them or insert new ones. — Slava Utesinov

Jerry Liu Jerry Liu · Accepted Answer · 2018-06-26T07:35:10

I also got etag exception when I use Merge to operate a entity not exist in table.

System.ArgumentException: 'Merge requires an ETag (which may be the '*' wildcard).'

Your requirement can be achieved by Retrieve and InsertOrMerge.

Add two properties Email and Address to your Item class.

 public class Item: TableEntity
 {
    public Item(String PartitionKey, String RowKey, String Name, String Email=null, String Address=null)
    {
        this.RowKey = RowKey ;
        this.PartitionKey = PartitionKey;
        this.Name = Name;
        this.Email = Email;
        this.Address = Address;
    }

    public Item(){}

    public String Name { get; set; }

    public String Email { get; set; }

    public String Address { get; set; }

}

Add if switch to tell which properties are to load.

 TableOperation to = TableOperation.Retrieve<Item>("PK","RK");

 TableResult tr = table.ExecuteAync(to).Result;

 var item;

 if (tr != null)
 {
     item = new Item
     {
         PartitionKey = "PARTITIONID",
         RowKey = "ROWID",                
         Name = "DEMO",  
     }
 }
 else
 {
     item = new Item
     {
         PartitionKey = "PARTITIONID",
         RowKey = "ROWID",                
         Name = "DEMO",  
         Email = "[email protected]",
         Address = "Britain"
     }
 }

 to = TableOperation.InsertOrMerge(item);

 tr = await ct.ExecuteAysnc(to).Result;

. When you execute InsertOrMerge,

If the item exists, its content(Name) will be updated by your new item.
If it doesn't exist, it will be inserted as expected.

Azure Table Storage InsertOrMerge

1 Answers