Passing cloud table as an input binding - azure

Question

I am trying to create an azure function which takes azure table as storage, which then i read in the function. I am able to run the function when i specify the below signature
public static async System.Threading.Tasks.Task RunAsync([TimerTrigger("0 */1 * * * *")]TimerInfo myTimer, [Table("CovidUpdateTable")]CloudTable ServiceFormTable, [Blob("outcontainer/{DateTime}", FileAccess.Write)] Stream outputBlob, ILogger log)
Here, I have to specify the table name in table attribute even when i have specified it in the binding config as below
{
"type": "table",
"name": "ServiceFormTable",
"tableName": "CovidUpdateTable",
"take": 50,
"connection": "AzureWebJobsStorage",
"direction": "in"
}
in portal c# script I can directly bind to CloudTable but in Visual studio, It throws an error if i remove the table attribute and use just cloudtable. I am not sure what is the purpose of tablename in this config when I have to specify the name in table attribute.

Answer 1

When we create the function in Azure portal, it will create a c# script function(csx file) and generate function.json file for us. And the function will read the configs from the function.json file autosomally. So we can directly configure binging in the file and do not need to configure things in the code. But when we create the function in Visual Studio, it will create c# function (cs file) and will not generate function.json file for us. And the function will not read the configs from the function.json file autosomally. So we need to configure these settings with attribute. For more details, please refer to the document
Update
If you want to use the binding properties in local.settings.json, please refer to the following steps
local.settings.json
{
"IsEncrypted": false,
"Values": {
"AzureWebJobsStorage": "",
"FUNCTIONS_WORKER_RUNTIME": "dotnet",
"TableConnection": "<your azure table connection string>",
"Tablename": "<your table name>"
}
}
Configure code. You should use [Table("%Tablename%",Connection = "TableConnection")]CloudTable cloudTable, to bing Azure table
For example
public static async Task<IActionResult> Run(
[HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
[Table("%Tablename%",Connection = "TableConnection")]CloudTable cloudTable,
ILogger log)
{
log.LogInformation("C# HTTP trigger function processed a request.");
log.LogInformation(cloudTable.Name);
var query = new TableQuery<DynamicTableEntity>();
foreach (var entity in
await cloudTable.ExecuteQuerySegmentedAsync(query, null))
{
log.LogInformation(
$"{entity.PartitionKey}\t{entity.RowKey}\t{entity.Timestamp}");
}
....
}
For more details, please refer to the document