ColinLeeo commented on code in PR #418:
URL: https://github.com/apache/tsfile/pull/418#discussion_r1973068875
##########
cpp/examples/cpp_examples/demo_read.cpp:
##########
@@ -20,78 +20,63 @@
#include <string>
#include <vector>
+#include "../c_examples/c_examples.h"
#include "cpp_examples.h"
-std::string field_to_string(storage::Field *value) {
- if (value->type_ == common::TEXT) {
- return std::string(value->value_.sval_);
- } else {
- std::stringstream ss;
- switch (value->type_) {
- case common::BOOLEAN:
- ss << (value->value_.bval_ ? "true" : "false");
- break;
- case common::INT32:
- ss << value->value_.ival_;
- break;
- case common::INT64:
- ss << value->value_.lval_;
- break;
- case common::FLOAT:
- ss << value->value_.fval_;
- break;
- case common::DOUBLE:
- ss << value->value_.dval_;
- break;
- case common::NULL_TYPE:
- ss << "NULL";
- break;
- default:
- ASSERT(false);
- break;
- }
- return ss.str();
- }
-}
-
+using namespace storage;
int demo_read() {
- std::cout << "begin to read tsfile from demo_ts.tsfile" << std::endl;
- std::string device_name = "root.db001.dev001";
- std::string measurement_name = "m001";
- storage::Path p1(device_name, measurement_name);
- std::vector<storage::Path> select_list;
- select_list.push_back(p1);
- storage::QueryExpression *query_expr =
- storage::QueryExpression::create(select_list, nullptr);
-
- common::init_config_value();
+ ERRNO code = 0;
+ libtsfile_init();
+ std::string table_name = "table1";
storage::TsFileReader reader;
- int ret = reader.open("cpp_rw.tsfile");
-
- std::cout << "begin to query expr" << std::endl;
- ASSERT(ret == 0);
- storage::ResultSet *qds = nullptr;
- ret = reader.query(query_expr, qds);
-
- storage::RowRecord *record;
- std::cout << "begin to dump data from tsfile ---" << std::endl;
- int row_cout = 0;
- do {
- if (qds->next()) {
- std::cout << "dump QDS : " << record->get_timestamp() << ",";
- record = qds->get_row_record();
- if (record) {
- int size = record->get_fields()->size();
- for (int i = 0; i < size; ++i) {
- std::cout << field_to_string(record->get_field(i)) << ",";
+ reader.open("test_cpp.tsfile");
+ storage::ResultSet* temp_ret = nullptr;
+ std::vector<std::string> columns;
+ columns.emplace_back("id1");
+ columns.emplace_back("id2");
+ columns.emplace_back("s1");
+ code = reader.query(table_name, columns, 0, 100, temp_ret);
+ auto ret = static_cast<storage::TableResultSet*>(temp_ret);
+ auto metadata = ret->get_metadata();
+ int column_num = metadata->get_column_count();
+ for (int i = 0; i < column_num; i++) {
+ std::cout << "column name: " << metadata->get_column_name(i)
+ << std::endl;
+ std::cout << "column type: " << metadata->get_column_type(i)
+ << std::endl;
+ }
+ bool has_next = false;
+ while (ret->next(has_next) == common::E_OK && has_next) {
Review Comment:
fixed
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