docs: add example code for synchronously query and write (#27)

Signed-off-by: ik <[email protected]>

examples/CMakeLists.txt

@@ -13,3 +13,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+
+add_subdirectory(sync)

examples/sync/CMakeLists.txt

@@ -0,0 +1,21 @@
+#
+# Copyright 2024 Huawei Cloud Computing Technologies Co., Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+add_executable(ExampleSyncQuery Query.cpp)
+add_executable(ExampleSyncWrite Write.cpp)
+
+target_link_libraries(ExampleSyncQuery PRIVATE ${PROJECT_NAME}::Client)
+target_link_libraries(ExampleSyncWrite PRIVATE ${PROJECT_NAME}::Client)

examples/sync/Query.cpp

@@ -0,0 +1,60 @@
+//
+// Copyright 2024 Huawei Cloud Computing Technologies Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+//
+// Example: Query from server synchronously.
+//
+
+#include <iostream>
+
+#include <opengemini/Client.hpp>
+#include <opengemini/ClientConfigBuilder.hpp>
+#include <opengemini/Exception.hpp>
+
+int main(int argc, char** argv)
+{
+    // Constructs an openGemini client object.
+    opengemini::Client client{ opengemini::ClientConfigBuilder()
+                                   // At least one server endpoint needed.
+                                   .AppendAddress({ "127.0.0.1", 8086 })
+                                   .Finalize() };
+
+    {
+        // Performs a query request and print the result, the operation will
+        // block until completes or an exception is thrown.
+        auto result = client.Query({
+            "ExampleDatabase",
+            "select * from ExampleMeasurement",
+        });
+        std::cout << result << std::endl;
+    }
+
+    {
+        // Performs a query which will fail.
+        try {
+            opengemini::QueryResult result = client.Query({
+                "ExampleDatabase",
+                {}, // Passing an empty <command> is not allowed
+            });
+        }
+        catch (const opengemini::Exception& exception) {
+            // Simply prints the exception information.
+            std::cout << exception << std::endl;
+        }
+    }
+
+    return 0;
+}

examples/sync/Write.cpp

@@ -0,0 +1,97 @@
+//
+// Copyright 2024 Huawei Cloud Computing Technologies Co., Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+//
+// Example: Write points synchronously.
+//
+
+#include <iostream>
+
+#include <opengemini/Client.hpp>
+#include <opengemini/ClientConfigBuilder.hpp>
+#include <opengemini/Exception.hpp>
+
+int main(int argc, char** argv)
+{
+    // Constructs an openGemini client object.
+    opengemini::Client client{ opengemini::ClientConfigBuilder()
+                                   // At least one server endpoint needed.
+                                   .AppendAddress({ "127.0.0.1", 8086 })
+                                   .Finalize() };
+
+    {
+        // Writes single point to server, the operation will
+        // block until completes or an exception is thrown.
+        client.Write("ExampleDatabase",
+                     {
+                         "ExampleMeasurement",
+                         {
+                             { "Weather", "sunny" },
+                             { "Humidity", 521 },
+                             { "Temperature", 38.1 },
+                         },
+                         std::chrono::system_clock::now(),
+                     });
+    }
+
+    {
+        // Constructs two points for writing.
+        opengemini::Point point1{
+            "ExampleMeasurement",
+            {
+                { "Weather", "sunny" },
+                { "Humidity", 521 },
+                { "Temperature", 38.1 },
+            },
+        };
+        opengemini::Point point2{
+            "ExampleMeasurement",
+            {
+                { "Weather", "rainy" },
+                { "Humidity", 333 },
+                { "Temperature", 36.5 },
+            },
+        };
+
+        // Writes multiple points to server, the operation will
+        // block until completes or an exception is thrown.
+        client.Write("ExampleDatabase",
+                     { std::move(point1), std::move(point2) });
+    }
+
+    {
+        // Performs a write request which will fail.
+        try {
+            opengemini::QueryResult result = client.Query({
+                "ExampleDatabase",
+                {}, // Passing an empty <command> is not allowed
+            });
+
+            client.Write("ExampleDatabase",
+                         {
+                             "ExampleMeasurement",
+                             {}, // Passing an empty fields map is not allowed
+                             std::chrono::system_clock::now(),
+                         });
+        }
+        catch (const opengemini::Exception& exception) {
+            // Simply print the exception information.
+            std::cout << exception << std::endl;
+        }
+    }
+
+    return 0;
+}