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php editor Yuzai presents to you: How to fix Query dynamodb request error? DynamoDB is a highly scalable NoSQL database service provided by Amazon. When using DynamoDB for querying, you may encounter various errors that affect the normal operation of the system. To fix these errors, you first need to carefully check the correctness of the query statement and ensure that the provided parameters and table structure match. In addition, you can also improve query performance by increasing Read Capacity and use appropriate indexes to optimize query speed. In addition, understanding and following DynamoDB's best practices, such as the rational use of batch operations and conditional expressions, can also effectively avoid query errors. Through the above methods, you can easily fix and optimize errors in DynamoDB queries and improve system stability and performance.
In dynamodb, I have a table that contains:
- email (primary key) - password (attribute) - rname (attribute)
I am using aws go sdk v1 to execute queries using only the database primary key:
The structure I want to unmarshal is:
type item struct { email string `json:"email"` password string `json:"password"` rname string `json:"rname"` }
and code:
result, err := client.Query(&dynamodb.QueryInput{ TableName: aws.String("accountsTable"), KeyConditions: map[string]*dynamodb.Condition{ "email": { ComparisonOperator: aws.String("EQ"), AttributeValueList: []*dynamodb.AttributeValue{ { S: aws.String(email), }, }, }, }, }) if err != nil { return false, err } item := []Item{} err = dynamodbattribute.UnmarshalListOfMaps(result.Items, &item) if err != nil { return false, err }
However, I get an invalid key issue. I check the key in the database and it also matches the key I print to the console.
Not sure how to fix this as the examples I've seen seem to work for theirs and look the same.
Any help to solve this problem would be greatly appreciated :)
You need to set the value of password and rname to omitempty
so that it won't Set to null because they are not keys and they should not be included in the query as it will throw an invalid key exception:
type item struct { email string `json:"email" dynamodbav:"email,omitempty"` password string `json:"password" dynamodbav:"password,omitempty"` rname string `json:"rname" dynamodbav:"rname,omitempty"` }
I think the problem is due to you trying to marshal the entire response into a single command, however, iteration works for me. (I don't use go).
package main import ( "github.com/aws/aws-sdk-go/aws" "github.com/aws/aws-sdk-go/aws/session" "github.com/aws/aws-sdk-go/service/dynamodb" "github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute" "fmt" ) func main() { // create session sess := session.must(session.newsessionwithoptions(session.options{ sharedconfigstate: session.sharedconfigenable, })) // create dynamodb client with logging client := dynamodb.new(sess, aws.newconfig()) type item struct { email string `dynamodbav: "email"` password string `dynamodbav: "password,omitempty"` rname string `dynamodbav: "rname,omitempty"` } result, err := client.query(&dynamodb.queryinput{ tablename: aws.string("accountstable"), keyconditions: map[string]*dynamodb.condition{ "email": { comparisonoperator: aws.string("eq"), attributevaluelist: []*dynamodb.attributevalue{ { s: aws.string("<a href="https://www.php.cn/link/89fee0513b6668e555959f5dc23238e9" class="__cf_email__" data-cfemail="aec2c6c0c0c9eecfc3cfd4c1c080cdc1c3">[email protected]</a>"), }, }, }, }, }) if err != nil { fmt.println("query api call failed:") fmt.println((err.error())) } for _, i := range result.items { item := item{} err = dynamodbattribute.unmarshalmap(i, &item) if err != nil { fmt.println("got error unmarshalling: %s", err) } fmt.println("email: ", item.email) fmt.println() } }
Also when you use a single key for email
it means there is at most 1 item with the same email address which means you should use getitem
instead Not query
:
package main import ( "fmt" "github.com/aws/aws-sdk-go/aws" "github.com/aws/aws-sdk-go/aws/session" "github.com/aws/aws-sdk-go/service/dynamodb" "github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute" ) func main() { // Item to Get type Item struct { Email string `dynamodbav: "email"` Password string `dynamodbav: "password,omitempty"` Rname string `dynamodbav: "rname,omitempty"` } // Create Session sess := session.Must(session.NewSessionWithOptions(session.Options{ SharedConfigState: session.SharedConfigEnable, })) // Create DynamoDB Client client := dynamodb.New(sess, aws.NewConfig()) // Get Item result, err := client.GetItem(&dynamodb.GetItemInput{ TableName: aws.String("accountsTable"), Key: map[string]*dynamodb.AttributeValue{ "email": { S: aws.String("<a href="https://www.php.cn/link/89fee0513b6668e555959f5dc23238e9" class="__cf_email__" data-cfemail="4a262224242d0a2b272b30252464292527">[email protected]</a>"), }, }, }) // Catch Error if err != nil { fmt.Println("GetItem API call failed:") fmt.Println((err.Error())) } item := Item{} // Unmarhsall err = dynamodbattribute.UnmarshalMap(result.Item, &item) if err != nil { panic(fmt.Sprintf("Failed to unmarshal Record, %v", err)) } // If Item Returns Empty if item.Email == "" { fmt.Println("Could not find Item") return } // Print Result fmt.Println("Found item:") fmt.Println("Email: ", item.Email) }
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