(DataFlex) DynamoDB - Query

The Query operation finds items based on primary key values. You can query any table or secondary index that has a composite primary key (a partition key and a sort key).

For more information, see https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Query.html

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoRest
    Boolean iSuccess
    Variant vAuthAws
    Handle hoAuthAws
    Boolean iBTls
    Integer iPort
    Boolean iBAutoReconnect
    Handle hoJson
    Variant vSbRequestBody
    Handle hoSbRequestBody
    Variant vSbResponseBody
    Handle hoSbResponseBody
    Integer iRespStatusCode
    Handle hoJsonResponse
    String sReplyDateTimeS
    String sPostedByS
    String sIdS
    Integer iConsumedCapacityCapacityUnits
    String sConsumedCapacityTableName
    Integer iCount
    Integer iScannedCount
    Integer i
    Integer iCount_i
    String sTemp1
    Integer iTemp1

    Get Create (RefClass(cComChilkatRest)) To hoRest
    If (Not(IsComObjectCreated(hoRest))) Begin
        Send CreateComObject of hoRest
    End

    // Implements the following CURL command:

    // curl -X POST https://dynamodb.us-west-2.amazonaws.com/ \
    //   -H "Accept-Encoding: identity" \
    //   -H "Content-Type: application/x-amz-json-1.0" \
    //   -H "Authorization: AWS4-HMAC-SHA256 Credential=<Credential>, SignedHeaders=<Headers>, Signature=<Signature>" \
    //   -H "X-Amz-Date: <Date>" \
    //   -H "X-Amz-Target: DynamoDB_20120810.Query" \
    //   -d '{
    //     "TableName": "Reply",
    //     "IndexName": "PostedBy-Index",
    //     "Limit": 3,
    //     "ConsistentRead": true,
    //     "ProjectionExpression": "Id, PostedBy, ReplyDateTime",
    //     "KeyConditionExpression": "Id = :v1 AND PostedBy BETWEEN :v2a AND :v2b",
    //     "ExpressionAttributeValues": {
    //         ":v1": {"S": "Amazon DynamoDB#DynamoDB Thread 1"},
    //         ":v2a": {"S": "User A"},
    //         ":v2b": {"S": "User C"}
    //     },
    //     "ReturnConsumedCapacity": "TOTAL"
    // }'

    // Use the following online tool to generate REST code from a CURL command
    // Convert a cURL Command to REST Source Code

    Get Create (RefClass(cComChilkatAuthAws)) To hoAuthAws
    If (Not(IsComObjectCreated(hoAuthAws))) Begin
        Send CreateComObject of hoAuthAws
    End
    Set ComAccessKey Of hoAuthAws To "AWS_ACCESS_KEY"
    Set ComSecretKey Of hoAuthAws To "AWS_SECRET_KEY"
    // Don't forget to change the region to your particular region. (Also make the same change in the call to Connect below.)
    Set ComRegion Of hoAuthAws To "us-west-2"
    Set ComServiceName Of hoAuthAws To "dynamodb"
    // SetAuthAws causes Chilkat to automatically add the following headers: Authorization, X-Amz-Date
    Get pvComObject of hoAuthAws to vAuthAws
    Get ComSetAuthAws Of hoRest vAuthAws To iSuccess

    // URL: https://dynamodb.us-west-2.amazonaws.com/
    Move True To iBTls
    Move 443 To iPort
    Move True To iBAutoReconnect
    Get ComConnect Of hoRest "dynamodb.us-west-2.amazonaws.com" iPort iBTls iBAutoReconnect To iSuccess
    If (iSuccess <> True) Begin
        Get ComConnectFailReason Of hoRest To iTemp1
        Showln "ConnectFailReason: " iTemp1
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Note: The above code does not need to be repeatedly called for each REST request.
    // The rest object can be setup once, and then many requests can be sent.  Chilkat will automatically
    // reconnect within a FullRequest* method as needed.  It is only the very first connection that is explicitly
    // made via the Connect method.

    // Use this online tool to generate code from sample JSON:
    // Generate Code to Create JSON

    // The following JSON is sent in the request body.

    // {
    //   "TableName": "Reply",
    //   "IndexName": "PostedBy-Index",
    //   "Limit": 3,
    //   "ConsistentRead": true,
    //   "ProjectionExpression": "Id, PostedBy, ReplyDateTime",
    //   "KeyConditionExpression": "Id = :v1 AND PostedBy BETWEEN :v2a AND :v2b",
    //   "ExpressionAttributeValues": {
    //     ":v1": {
    //       "S": "Amazon DynamoDB#DynamoDB Thread 1"
    //     },
    //     ":v2a": {
    //       "S": "User A"
    //     },
    //     ":v2b": {
    //       "S": "User C"
    //     }
    //   },
    //   "ReturnConsumedCapacity": "TOTAL"
    // }

    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get ComUpdateString Of hoJson "TableName" "Reply" To iSuccess
    Get ComUpdateString Of hoJson "IndexName" "PostedBy-Index" To iSuccess
    Get ComUpdateInt Of hoJson "Limit" 3 To iSuccess
    Get ComUpdateBool Of hoJson "ConsistentRead" True To iSuccess
    Get ComUpdateString Of hoJson "ProjectionExpression" "Id, PostedBy, ReplyDateTime" To iSuccess
    Get ComUpdateString Of hoJson "KeyConditionExpression" "Id = :v1 AND PostedBy BETWEEN :v2a AND :v2b" To iSuccess
    Get ComUpdateString Of hoJson "ExpressionAttributeValues.:v1.S" "Amazon DynamoDB#DynamoDB Thread 1" To iSuccess
    Get ComUpdateString Of hoJson "ExpressionAttributeValues.:v2a.S" "User A" To iSuccess
    Get ComUpdateString Of hoJson "ExpressionAttributeValues.:v2b.S" "User C" To iSuccess
    Get ComUpdateString Of hoJson "ReturnConsumedCapacity" "TOTAL" To iSuccess

    Get ComAddHeader Of hoRest "Content-Type" "application/x-amz-json-1.0" To iSuccess
    Get ComAddHeader Of hoRest "X-Amz-Target" "DynamoDB_20120810.Query" To iSuccess
    Get ComAddHeader Of hoRest "Accept-Encoding" "identity" To iSuccess

    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbRequestBody
    If (Not(IsComObjectCreated(hoSbRequestBody))) Begin
        Send CreateComObject of hoSbRequestBody
    End
    Get pvComObject of hoSbRequestBody to vSbRequestBody
    Get ComEmitSb Of hoJson vSbRequestBody To iSuccess
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbResponseBody
    If (Not(IsComObjectCreated(hoSbResponseBody))) Begin
        Send CreateComObject of hoSbResponseBody
    End
    Get pvComObject of hoSbRequestBody to vSbRequestBody
    Get pvComObject of hoSbResponseBody to vSbResponseBody
    Get ComFullRequestSb Of hoRest "POST" "/" vSbRequestBody vSbResponseBody To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRest To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComResponseStatusCode Of hoRest To iRespStatusCode
    Showln "response status code = " iRespStatusCode
    If (iRespStatusCode >= 400) Begin
        Showln "Response Status Code = " iRespStatusCode
        Showln "Response Header:"
        Get ComResponseHeader Of hoRest To sTemp1
        Showln sTemp1
        Showln "Response Body:"
        Get ComGetAsString Of hoSbResponseBody To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatJsonObject)) To hoJsonResponse
    If (Not(IsComObjectCreated(hoJsonResponse))) Begin
        Send CreateComObject of hoJsonResponse
    End
    Get pvComObject of hoSbResponseBody to vSbResponseBody
    Get ComLoadSb Of hoJsonResponse vSbResponseBody To iSuccess

    Set ComEmitCompact Of hoJsonResponse To False
    Get ComEmit Of hoJsonResponse To sTemp1
    Showln sTemp1

    // Sample JSON response:
    // (Sample code for parsing the JSON response is shown below)

    // {
    //   "ConsumedCapacity": {
    //     "CapacityUnits": 1,
    //     "TableName": "Reply"
    //   },
    //   "Count": 2,
    //   "Items": [
    //     {
    //       "ReplyDateTime": {
    //         "S": "2015-02-18T20:27:36.165Z"
    //       },
    //       "PostedBy": {
    //         "S": "User A"
    //       },
    //       "Id": {
    //         "S": "Amazon DynamoDB#DynamoDB Thread 1"
    //       }
    //     },
    //     {
    //       "ReplyDateTime": {
    //         "S": "2015-02-25T20:27:36.165Z"
    //       },
    //       "PostedBy": {
    //         "S": "User B"
    //       },
    //       "Id": {
    //         "S": "Amazon DynamoDB#DynamoDB Thread 1"
    //       }
    //     }
    //   ],
    //   "ScannedCount": 2
    // }

    // Sample code for parsing the JSON response...
    // Use the following online tool to generate parsing code from sample JSON:
    // Generate Parsing Code from JSON

    Get ComIntOf Of hoJsonResponse "ConsumedCapacity.CapacityUnits" To iConsumedCapacityCapacityUnits
    Get ComStringOf Of hoJsonResponse "ConsumedCapacity.TableName" To sConsumedCapacityTableName
    Get ComIntOf Of hoJsonResponse "Count" To iCount
    Get ComIntOf Of hoJsonResponse "ScannedCount" To iScannedCount
    Move 0 To i
    Get ComSizeOfArray Of hoJsonResponse "Items" To iCount_i
    While (i < iCount_i)
        Set ComI Of hoJsonResponse To i
        Get ComStringOf Of hoJsonResponse "Items[i].ReplyDateTime.S" To sReplyDateTimeS
        Get ComStringOf Of hoJsonResponse "Items[i].PostedBy.S" To sPostedByS
        Get ComStringOf Of hoJsonResponse "Items[i].Id.S" To sIdS
        Move (i + 1) To i
    Loop



End_Procedure