

There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Use `StartQuery` with an AWS SDK
<a name="cloudwatch-logs_example_cloudwatch-logs_StartQuery_section"></a>

The following code examples show how to use `StartQuery`.

Action examples are code excerpts from larger programs and must be run in context. You can see this action in context in the following code example: 
+  [Run a large query](cloudwatch-logs_example_cloudwatch-logs_Scenario_BigQuery_section.md) 

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#### [ .NET ]

**SDK for .NET (v4)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/CloudWatchLogs/LargeQuery#code-examples). 

```
    /// <summary>
    /// Starts a CloudWatch Logs Insights query.
    /// </summary>
    /// <param name="logGroupName">The name of the log group to query.</param>
    /// <param name="queryString">The CloudWatch Logs Insights query string.</param>
    /// <param name="startTime">The start time for the query (seconds since epoch).</param>
    /// <param name="endTime">The end time for the query (seconds since epoch).</param>
    /// <param name="limit">The maximum number of results to return.</param>
    /// <returns>The query ID if successful, null otherwise.</returns>
    public async Task<string?> StartQueryAsync(
        string logGroupName,
        string queryString,
        long startTime,
        long endTime,
        int limit = 10000)
    {
        try
        {
            var request = new StartQueryRequest
            {
                LogGroupName = logGroupName,
                QueryString = queryString,
                StartTime = startTime,
                EndTime = endTime,
                Limit = limit
            };

            var response = await _amazonCloudWatchLogs.StartQueryAsync(request);
            return response.QueryId;
        }
        catch (InvalidParameterException ex)
        {
            _logger.LogError($"Invalid parameter for query: {ex.Message}");
            return null;
        }
        catch (ResourceNotFoundException ex)
        {
            _logger.LogError($"Log group not found: {ex.Message}");
            return null;
        }
        catch (Exception ex)
        {
            _logger.LogError($"An error occurred while starting query: {ex.Message}");
            return null;
        }
    }
```
+  For API details, see [StartQuery](https://docs.aws.amazon.com/goto/DotNetSDKV4/logs-2014-03-28/StartQuery) in *AWS SDK for .NET API Reference*. 

------
#### [ JavaScript ]

**SDK for JavaScript (v3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/cloudwatch-logs#code-examples). 

```
  /**
   * Wrapper for the StartQueryCommand. Uses a static query string
   * for consistency.
   * @param {[Date, Date]} dateRange
   * @param {number} maxLogs
   * @returns {Promise<{ queryId: string }>}
   */
  async _startQuery([startDate, endDate], maxLogs = 10000) {
    try {
      return await this.client.send(
        new StartQueryCommand({
          logGroupNames: this.logGroupNames,
          queryString: "fields @timestamp, @message | sort @timestamp asc",
          startTime: startDate.valueOf(),
          endTime: endDate.valueOf(),
          limit: maxLogs,
        }),
      );
    } catch (err) {
      /** @type {string} */
      const message = err.message;
      if (message.startsWith("Query's end date and time")) {
        // This error indicates that the query's start or end date occur
        // before the log group was created.
        throw new DateOutOfBoundsError(message);
      }

      throw err;
    }
  }
```
+  For API details, see [StartQuery](https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/client/cloudwatch-logs/command/StartQueryCommand) in *AWS SDK for JavaScript API Reference*. 

------
#### [ Python ]

**SDK for Python (Boto3)**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/cloudwatch-logs#code-examples). 

```
    def perform_query(self, date_range):
        """
        Performs the actual CloudWatch log query.

        :param date_range: A tuple representing the start and end datetime for the query.
        :type date_range: tuple
        :return: A list containing the query results.
        :rtype: list
        """
        client = boto3.client("logs")
        try:
            try:
                start_time = round(
                    self.date_utilities.convert_iso8601_to_unix_timestamp(date_range[0])
                )
                end_time = round(
                    self.date_utilities.convert_iso8601_to_unix_timestamp(date_range[1])
                )
                response = client.start_query(
                    logGroupName=self.log_group,
                    startTime=start_time,
                    endTime=end_time,
                    queryString=self.query_string,
                    limit=self.limit,
                )
                query_id = response["queryId"]
            except client.exceptions.ResourceNotFoundException as e:
                raise DateOutOfBoundsError(f"Resource not found: {e}")
            while True:
                time.sleep(1)
                results = client.get_query_results(queryId=query_id)
                if results["status"] in [
                    "Complete",
                    "Failed",
                    "Cancelled",
                    "Timeout",
                    "Unknown",
                ]:
                    return results.get("results", [])
        except DateOutOfBoundsError:
            return []

    def _initiate_query(self, client, date_range, max_logs):
        """
        Initiates the CloudWatch logs query.

        :param date_range: A tuple representing the start and end datetime for the query.
        :type date_range: tuple
        :param max_logs: The maximum number of logs to retrieve.
        :type max_logs: int
        :return: The query ID as a string.
        :rtype: str
        """
        try:
            start_time = round(
                self.date_utilities.convert_iso8601_to_unix_timestamp(date_range[0])
            )
            end_time = round(
                self.date_utilities.convert_iso8601_to_unix_timestamp(date_range[1])
            )
            response = client.start_query(
                logGroupName=self.log_group,
                startTime=start_time,
                endTime=end_time,
                queryString=self.query_string,
                limit=max_logs,
            )
            return response["queryId"]
        except client.exceptions.ResourceNotFoundException as e:
            raise DateOutOfBoundsError(f"Resource not found: {e}")
```
+  For API details, see [StartQuery](https://docs.aws.amazon.com/goto/boto3/logs-2014-03-28/StartQuery) in *AWS SDK for Python (Boto3) API Reference*. 

------
#### [ SAP ABAP ]

**SDK for SAP ABAP**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/cwl#code-examples). 

```
    TRY.
        " iv_log_group_name = '/aws/lambda/my-function'
        " iv_query_string = 'fields @timestamp, @message | sort @timestamp desc | limit 20'
        " iv_start_time and iv_end_time must be in Unix epoch milliseconds (ms since Jan 1, 1970 00:00:00 UTC)
        oo_result = lo_cwl->startquery(
          iv_loggroupname = iv_log_group_name
          iv_starttime    = iv_start_time
          iv_endtime      = iv_end_time
          iv_querystring  = iv_query_string
          iv_limit        = iv_limit ).
        
        " Display the query ID for tracking
        DATA(lv_query_id) = oo_result->get_queryid( ).
        MESSAGE |Query started successfully with ID: { lv_query_id }| TYPE 'I'.
      CATCH /aws1/cx_cwlinvalidparameterex.
        MESSAGE 'Invalid parameter.' TYPE 'E'.
      CATCH /aws1/cx_cwllimitexceededex.
        MESSAGE 'Limit exceeded.' TYPE 'E'.
      CATCH /aws1/cx_cwlmalformedqueryex.
        MESSAGE 'Malformed query.' TYPE 'E'.
      CATCH /aws1/cx_cwlresourcenotfoundex.
        MESSAGE 'Resource not found.' TYPE 'E'.
      CATCH /aws1/cx_cwlserviceunavailex.
        MESSAGE 'Service unavailable.' TYPE 'E'.
    ENDTRY.
```
+  For API details, see [StartQuery](https://docs.aws.amazon.com/sdk-for-sap-abap/v1/api/latest/index.html) in *AWS SDK for SAP ABAP API reference*. 

------