DynamoDB query with Ruby SDK - ruby

Question

I'm really struggling to make queries work. I'm trying to get all items with primary key ('keyword') equal to 'compost spoons'.
This is one of my items:
{
"keyword": "compost spoons",
"created_at": "2020-08-12T11:31:21+00:00"
}
And this is the params in my query:
params = {
table_name: "servings",
select: "ALL_ATTRIBUTES",
return_consumed_capacity: "INDEXES",
key_condition_expression: "keyword = :keyword_val",
expression_attribute_values: {
"keyword_val" => "compost spoon"
}
}
Error that it throughs:
"ExpressionAttributeValues contains invalid key: Syntax error; key: \"keyword_val\""
What should be the params in order for the query to work?
The schema:
{
"AttributeDefinitions": [
{
"AttributeName": "keyword",
"AttributeType": "S"
},
{
"AttributeName": "created_at",
"AttributeType": "S"
}
],
"TableName": "servings",
"KeySchema": [
{
"AttributeName": "keyword",
"KeyType": "HASH"
},
{
"AttributeName": "created_at",
"KeyType": "RANGE"
}
],
"TableStatus": "ACTIVE",
"CreationDateTime": "2020-08-14T10:26:55.528Z",
"ProvisionedThroughput": {
"LastIncreaseDateTime": "1970-01-01T00:00:00.000Z",
"LastDecreaseDateTime": "1970-01-01T00:00:00.000Z",
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 5,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 168,
"ItemCount": 3,
"TableArn": "arn:aws:dynamodb:ddblocal:000000000000:table/servings"
}

Answer 1

Looks like you're missing a colon in front of your keyword_val in the expression_attribute_values. I believe it should be:
params = {
table_name: "servings",
select: "ALL_ATTRIBUTES",
return_consumed_capacity: "INDEXES",
key_condition_expression: "keyword = :keyword_val",
expression_attribute_values: {
":keyword_val" => "compost spoon". // <---- CHANGE IS HERE!!
}
}