DataFlex
DataFlex
DynamoDB - Query
See more Amazon DynamoDB Examples
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).Chilkat DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
Handle hoRest
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
Move False To iSuccess
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