Add c, cpp examples

examples/README.md

@@ -0,0 +1,8 @@
+# Examples
+This directory contains examples of how to use the library. 
+
+To use with CLion, add `add_subdirectory()` to the CMakeLists.txt file in the root directory of the project. 
+E.g. to use cpp example
+```
+add_subdirectory(examples/cpp)
+```

examples/c/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.11)
+project(example-c)
+
+include_directories(../../src/include)
+link_directories(../../build/release/src)
+
+add_executable(example-c main.c)
+target_link_libraries(example-c kuzu)

examples/c/main.c

@@ -0,0 +1,48 @@
+#include <stdio.h>
+
+#include "c_api/kuzu.h"
+
+int main() {
+    kuzu_database* db = kuzu_database_init("" /* fill db path */, 0);
+    kuzu_connection* conn = kuzu_connection_init(db);
+
+    kuzu_query_result* result;
+    // Create schema.
+    result = kuzu_connection_query(
+        conn, "CREATE NODE TABLE Person(name STRING, age INT64, PRIMARY KEY(name));");
+    kuzu_query_result_destroy(result);
+    // Create nodes.
+    result = kuzu_connection_query(conn, "CREATE (:Person {name: 'Alice', age: 25});");
+    kuzu_query_result_destroy(result);
+    result = kuzu_connection_query(conn, "CREATE (:Person {name: 'Bob', age: 30});");
+    kuzu_query_result_destroy(result);
+
+    // Execute a simple query.
+    result = kuzu_connection_query(
+        conn, "MATCH (a:Person) RETURN a.name AS NAME, a.age AS AGE;");
+
+    // Fetch each value.
+    while (kuzu_query_result_has_next(result)) {
+        kuzu_flat_tuple* tuple = kuzu_query_result_get_next(result);
+
+        kuzu_value* value = kuzu_flat_tuple_get_value(tuple, 0);
+        char* name = kuzu_value_get_string(value);
+        kuzu_value_destroy(value);
+
+        value = kuzu_flat_tuple_get_value(tuple, 1);
+        int64_t age = kuzu_value_get_int64(value);
+        kuzu_value_destroy(value);
+
+        printf("name: %s, age: %lld \n", name, age);
+        free(name);
+        kuzu_flat_tuple_destroy(tuple);
+    }
+
+    // Print query result.
+    printf("%s", kuzu_query_result_to_string(result));
+
+    kuzu_query_result_destroy(result);
+    kuzu_connection_destroy(conn);
+    kuzu_database_destroy(db);
+    return 0;
+}

examples/cpp/CMakeLists.txt

@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.11)
+project(example-cpp)
+
+set(CMAKE_CXX_STANDARD 20)
+
+include_directories(../../src/include)
+link_directories(../../build/release/src)
+
+add_executable(example-cpp main.cpp)
+target_link_libraries(example-cpp kuzu)

examples/cpp/main.cpp

@@ -0,0 +1,20 @@
+#include <iostream>
+
+#include "main/kuzu.h"
+using namespace kuzu::main;
+
+int main() {
+    auto database = std::make_unique<Database>("" /* fill db path */);
+    auto connection = std::make_unique<Connection>(database.get());
+
+    // Create schema.
+    connection->query("CREATE NODE TABLE Person(name STRING, age INT64, PRIMARY KEY(name));");
+    // Create nodes.
+    connection->query("CREATE (:Person {name: 'Alice', age: 25});");
+    connection->query("CREATE (:Person {name: 'Bob', age: 30});");
+
+    // Execute a simple query.
+    auto result = connection->query("MATCH (a:Person) RETURN a.name AS NAME, a.age AS AGE;");
+    // Print query result.
+    std::cout << result->toString();
+}

src/c_api/flat_tuple.cpp

@@ -32,14 +32,9 @@ kuzu_value* kuzu_flat_tuple_get_value(kuzu_flat_tuple* flat_tuple, uint64_t inde
     return value;
 }
 
-char* kuzu_flat_tuple_to_string(kuzu_flat_tuple* flat_tuple, const uint32_t* columns_width,
-    uint64_t columns_width_length, const char* delimiter, uint32_t max_width) {
+char* kuzu_flat_tuple_to_string(kuzu_flat_tuple* flat_tuple) {
     auto flat_tuple_shared_ptr = static_cast<std::shared_ptr<FlatTuple>*>(flat_tuple->_flat_tuple);
-    std::vector<uint32_t> columns_width_vector;
-    for (uint64_t i = 0; i < columns_width_length; i++) {
-        columns_width_vector.push_back(columns_width[i]);
-    }
-    auto string = (*flat_tuple_shared_ptr)->toString(columns_width_vector, delimiter, max_width);
+    auto string = (*flat_tuple_shared_ptr)->toString();
     char* string_c = (char*)malloc(string.size() + 1);
     strcpy(string_c, string.c_str());
     return string_c;

src/c_api/query_result.cpp

@@ -79,6 +79,13 @@ kuzu_flat_tuple* kuzu_query_result_get_next(kuzu_query_result* query_result) {
     return flat_tuple_c;
 }
 
+char* kuzu_query_result_to_string(kuzu_query_result* query_result) {
+    auto string = static_cast<QueryResult*>(query_result->_query_result)->toString();
+    char* string_c = (char*)malloc(string.size() + 1);
+    strcpy(string_c, string.c_str());
+    return string_c;
+}
+
 void kuzu_query_result_write_to_csv(kuzu_query_result* query_result, const char* file_path,
     char delimiter, char escape_char, char new_line) {
     static_cast<QueryResult*>(query_result->_query_result)

src/include/c_api/kuzu.h

@@ -154,16 +154,15 @@ KUZU_C_API uint64_t kuzu_query_result_get_num_tuples(kuzu_query_result* query_re
 KUZU_C_API kuzu_query_summary* kuzu_query_result_get_query_summary(kuzu_query_result* query_result);
 KUZU_C_API bool kuzu_query_result_has_next(kuzu_query_result* query_result);
 KUZU_C_API kuzu_flat_tuple* kuzu_query_result_get_next(kuzu_query_result* query_result);
+KUZU_C_API char* kuzu_query_result_to_string(kuzu_query_result* query_result);
 KUZU_C_API void kuzu_query_result_write_to_csv(kuzu_query_result* query_result,
     const char* file_path, char delimiter, char escape_char, char new_line);
 KUZU_C_API void kuzu_query_result_reset_iterator(kuzu_query_result* query_result);
 
 // FlatTuple
 KUZU_C_API void kuzu_flat_tuple_destroy(kuzu_flat_tuple* flat_tuple);
 KUZU_C_API kuzu_value* kuzu_flat_tuple_get_value(kuzu_flat_tuple* flat_tuple, uint64_t index);
-KUZU_C_API char* kuzu_flat_tuple_to_string(kuzu_flat_tuple* flat_tuple,
-    const uint32_t* columns_width, uint64_t columns_width_length, const char* delimiter,
-    uint32_t max_width);
+KUZU_C_API char* kuzu_flat_tuple_to_string(kuzu_flat_tuple* flat_tuple);
 
 // DataType
 KUZU_C_API kuzu_data_type* kuzu_data_type_create(

src/include/main/query_result.h

@@ -78,6 +78,8 @@ class QueryResult {
      * @return next flat tuple in the query result.
      */
     KUZU_API std::shared_ptr<processor::FlatTuple> getNext();
+
+    std::string toString();
     /**
      * @brief writes the query result to a csv file.
      * @param fileName name of the csv file.

src/include/processor/result/flat_tuple.h

@@ -24,6 +24,8 @@ class FlatTuple {
      */
     KUZU_API common::Value* getValue(uint32_t idx);
 
+    std::string toString();
+
     /**
      * @param colsWidth The length of each column
      * @param delimiter The delimiter to separate each value.

src/main/query_result.cpp

@@ -195,6 +195,24 @@ std::shared_ptr<FlatTuple> QueryResult::getNext() {
     return tuple;
 }
 
+std::string QueryResult::toString() {
+    std::string result;
+    // print header
+    for (auto i = 0u; i < columnNames.size(); ++i) {
+        if (i != 0) {
+            result += "|";
+        }
+        result += columnNames[i];
+    }
+    result += "\n";
+    resetIterator();
+    while (hasNext()) {
+        getNext();
+        result += tuple->toString();
+    }
+    return result;
+}
+
 void QueryResult::writeToCSV(
     const std::string& fileName, char delimiter, char escapeCharacter, char newline) {
     std::ofstream file;

src/processor/result/flat_tuple.cpp

@@ -25,6 +25,18 @@ common::Value* FlatTuple::getValue(uint32_t idx) {
     return values[idx].get();
 }
 
+std::string FlatTuple::toString() {
+    std::string result;
+    for (auto i = 0ul; i < values.size(); i++) {
+        if (i != 0) {
+            result += "|";
+        }
+        result += values[i]->toString();
+    }
+    result += "\n";
+    return result;
+}
+
 std::string FlatTuple::toString(
     const std::vector<uint32_t>& colsWidth, const std::string& delimiter, const uint32_t maxWidth) {
     std::ostringstream result;

test/c_api/flat_tuple_test.cpp

@@ -54,8 +54,8 @@ TEST_F(CApiFlatTupleTest, ToString) {
     columnWidths[0] = 10;
     columnWidths[1] = 5;
     columnWidths[2] = 10;
-    auto str = kuzu_flat_tuple_to_string(flatTuple, columnWidths, 3, "\t", 1024);
-    ASSERT_EQ(std::string(str), " Alice    \t 35  \t 1.731000 ");
+    auto str = kuzu_flat_tuple_to_string(flatTuple);
+    ASSERT_EQ(std::string(str), "Alice|35|1.731000\n");
     free(str);
     free(columnWidths);
     kuzu_flat_tuple_destroy(flatTuple);