This topic describes how to use Log Service SDK for C++ to use the Dedicated SQL feature.
Prerequisites
Background information
- ExecuteLogStoreSql: uses the Dedicated SQL feature in a specified Logstore. This API
operation supports the SQL-92 syntax. A query statement is in the
Search statement|Analytic statement
format and the analytic statement follows the standard SQL-92 syntax. - ExecuteProjectSql: uses the Dedicated SQL feature in a specified project. This API operation supports the SQL-92 syntax. You must specify a filter condition and time range in the WHERE clause of an SQL statement.
Search statement|Analytic statement
format. This improves analysis efficiency.
Sample code
The following sample code shows how to use the Dedicated SQL feature. For more information, see Alibaba Cloud Log Service SDK for C++.
// The endpoint of Log Service. For more information, see Endpoints. In this example, the endpoint of the China (Hangzhou) region is used. Replace the parameter value with the actual endpoint.
std::string endpoint = "cn-hangzhou.log.aliyuncs.com";
// The AccessKey pair that is used to access Log Service. For more information, see AccessKey pair. An Alibaba Cloud account has permissions to call all API operations. If you use the AccessKey pair of your Alibaba Cloud account, your resources are exposed to high security risks. We recommend that you log on as a RAM user that has permissions to call API operations or perform routine O&M tasks.
std::string accessId = "your_access_id";
std::string accessKey = "your_access_key";
// The name of the project.
std::string project = "your_project_name";
// The name of the Logstore.
std::string logStore = "your_logstore";
// Create a Log Service client.
LOGClient client(endpoint, accessId, accessKey);
// Execute an SQL statement in the specified Logstore.
try
{
std::string sql = "* | select count(1)";
int from = time(NULL) - 600;
int to = from + 600;
LogStoreSqlResponse logsResponse = client.ExecuteLogStoreSql(project, logStore,
1627268185,1627269085,"* | SELECT count(*)",true);
// Print the statistics of the analysis result.
std::cout << "Returned sql result:" << std::endl
<< "count:" << logsResponse.result.logline << std::endl // The number of rows of log data that is returned in the analysis result.
<< "processed rows:" << logsResponse.processedRows << std::endl // The number of rows of log data that is processed.
<< "elapsed milli:" << logsResponse.elapsedMilli << std::endl // The time that is required to execute the SQL statement.
<< "cpu sec:" << logsResponse.cpuSec << std::endl // The CPU time that is consumed to execute the SQL statement after the Dedicated SQL feature is enabled. Unit: seconds. You are charged for the CPU time that is consumed when you use the Dedicated SQL feature to perform query and analysis operations. For more information, see Billable items.
<< "cpu core:" << logsResponse.cpuCore << std::endl; // The number of CPU cores that are used to execute the SQL statement after the Dedicated SQL feature is enabled.
for (std::vector<LogItem>::const_iterator itr = logsResponse.result.logdatas.begin();
itr != logsResponse.result.logdatas.end(); ++itr)
{
const LogItem &item = *itr;
for (std::vector<std::pair<std::string, std::string>>::const_iterator itr_data = item.data.begin();
itr_data != item.data.end(); ++itr_data)
{
std::cout << itr_data->first << ":" << itr_data->second;
}
}
}
catch (LOGException &e)
{
std::cout << "error code :" << e.GetErrorCode() << std::endl;
std::cout << "error message :" << e.GetMessage() << std::endl;
throw e;
}
// Execute an SQL statement in the specified project.
try
{
int now = time(NULL);
std::string sql = "select count(1) as cnt from xxx where __time__ > " + to_string(now);
ProjectSqlResponse logsResponse = client.ExecuteProjectSql(project,"select avg(latency),max(latency) ,count(1) as c from sample-logstore where status>200 and __time__>=1500975424 and __time__ < 1501035044 GROUP BY method ORDER BY c",true);
// Print the statistics of the analysis result.
std::cout << "Returned sql result:" << std::endl
<< "count:" << logsResponse.result.logline << std::endl // The number of rows of log data that is returned in the analysis result.
<< "processed rows:" << logsResponse.processedRows << std::endl // The number of rows of log data that is processed.
<< "elapsed milli:" << logsResponse.elapsedMilli << std::endl // The time that is required to execute the SQL statement.
<< "cpu sec:" << logsResponse.cpuSec << std::endl // The CPU time that is consumed to execute the SQL statement after the Dedicated SQL feature is enabled. Unit: seconds. You are charged for the CPU time that is consumed when you use the Dedicated SQL feature to perform query and analysis operations. For more information, see Billable items.
<< "cpu core:" << logsResponse.cpuCore << std::endl; // The number of CPU cores that are used to execute the SQL statement after the Dedicated SQL feature is enabled.
for (std::vector<LogItem>::const_iterator itr = logsResponse.result.logdatas.begin(); itr != logsResponse.result.logdatas.end(); ++itr)
{
const LogItem &item = *itr;
for (std::vector<std::pair<std::string, std::string>>::const_iterator itr_data = item.data.begin();
itr_data != item.data.end(); ++itr_data)
{
std::cout << itr_data->first << ":" << itr_data->second;
}
}
}
catch (LOGException &e)
{
std::cout << "error code :" << e.GetErrorCode() << std::endl;
std::cout << "error message :" << e.GetMessage() << std::endl;
throw e;
}
- ExecuteLogStoreSql operation
You can call the ExecuteLogStoreSql operation to use the Dedicated SQL feature. Requests must be in the
LogStoreSqlResponse logsResponse = client.ExecuteLogStoreSql(project, logStore, from, to, query, powerSql)
format. The following table describes the request parameters.Parameter Type Required Example Description project String Yes N/A The name of the project. When you create a Log Service client, you must specify a value for the project parameter. Therefore, you do not need to set the parameter again.
logStore String Yes N/A The name of the Logstore. When you create a Log Service client, you must specify a value for the logStore parameter. Therefore, you do not need to set the parameter again.
from Long Yes 1627268185 The start time of the time range that is specified in the request. The start time is a timestamp that follows the UNIX time format. It is the number of seconds that have elapsed since 00:00:00 UTC, Thursday, January 1, 1970. to Long Yes 1627269085 The end time of the time range that is specified in the request. The end time is a timestamp that follows the UNIX time format. It is the number of seconds that have elapsed since 00:00:00 UTC, Thursday, January 1, 1970. query String Yes "* | SELECT count(*)"
The query statement. Format: Search statement|Analytic statement
For more information, see Syntax.By default, Log Service returns 100 rows of data. You can use a LIMIT clause to specify the number of rows of data to return. For more information, see LIMIT syntax.
powerSql Boolean No true Specifies whether to use the Dedicated SQL feature. For more information, see Enable Dedicated SQL. - true: The Dedicated SQL feature is used.
- false: The Standard SQL feature is used. This is the default value.
- ExecuteProjectSql operation
You can call the ExecuteProjectSql operation to use the Dedicated SQL feature. Requests must be in the
ProjectSqlResponse logsResponse = client.ExecuteProjectSql(project, query, powerSql)
format. The following table describes the request parameters.Parameter Type Required Example Description project String Yes N/A The name of the project. When you create a Log Service client, you must specify a value for the project parameter. Therefore, you do not need to set the parameter again.
query String Yes "select avg(latency),max(latency) ,count(1) as c from sample-logstore where status>200 and __time__>=1500975424 and __time__ < 1501035044 GROUP BY method ORDER BY c"
An SQL statement in which a filter condition and time range must be specified in the WHERE clause. By default, Log Service returns 100 rows of data. You can use a LIMIT clause to specify the number of rows of data to return. For more information, see LIMIT syntax.
powerSql Boolean No true Specifies whether to use the Dedicated SQL feature. For more information, see Enable Dedicated SQL. - true: The Dedicated SQL feature is used.
- false: The Standard SQL feature is used. This is the default value.