AWS dynamodb can't update item using .net api

Question

when I update item using .net api, it always say 'The provided key element does not match the schema' this is my code:

    try
{
    var dic = new Dictionary<string, AttributeValue>()
    {
        { "report_id",new AttributeValue(){ S="isYCga2laNFnjJzz"} },
        { "time_report",new AttributeValue(){ N="0"} }
    };
    await client.UpdateItemAsync("project8_Dev_user_report", dic, null);
}
catch (Exception e)
{
    Debug.LogError(e);
}

and my database look like:

PS: this is my table schema

Answer 1

Your parameters for UpdateItem are wrong. It should be something similar to this:

AmazonDynamoDBClient client = new AmazonDynamoDBClient();
string tableName = "ProductCatalog";

var request = new UpdateItemRequest
{
    TableName = tableName,
    Key = new Dictionary<string,AttributeValue>() { { "Id", new AttributeValue { N = "202" } } },
    ExpressionAttributeNames = new Dictionary<string,string>()
    {
        {"#A", "Authors"},
        {"#P", "Price"},
        {"#NA", "NewAttribute"},
        {"#I", "ISBN"}
    },
    ExpressionAttributeValues = new Dictionary<string, AttributeValue>()
    {
        {":auth",new AttributeValue { SS = {"Author YY","Author ZZ"}}},
        {":p",new AttributeValue {N = "1"}},
        {":newattr",new AttributeValue {S = "someValue"}},
    },

    // This expression does the following:
    // 1) Adds two new authors to the list
    // 2) Reduces the price
    // 3) Adds a new attribute to the item
    // 4) Removes the ISBN attribute from the item
    UpdateExpression = "ADD #A :auth SET #P = #P - :p, #NA = :newattr REMOVE #I"
};
var response = client.UpdateItem(request);

It should contain a Key and an UpdateExression at a minimum.