本文整理汇总了C++中StoragePtr::getDataTypeByName方法的典型用法代码示例。如果您正苦于以下问题：C++ StoragePtr::getDataTypeByName方法的具体用法？C++ StoragePtr::getDataTypeByName怎么用？C++ StoragePtr::getDataTypeByName使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类StoragePtr的用法示例。
在下文中一共展示了StoragePtr::getDataTypeByName方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: main
int main(int argc, char ** argv)
try
{
using namespace DB;
const size_t rows = 10000000;
/// создаём таблицу с парой столбцов
NamesAndTypesListPtr names_and_types = std::make_shared<NamesAndTypesList>();
names_and_types->push_back(NameAndTypePair("a", std::make_shared<DataTypeUInt64>()));
names_and_types->push_back(NameAndTypePair("b", std::make_shared<DataTypeUInt8>()));
StoragePtr table = StorageLog::create("./", "test", names_and_types);
/// пишем в неё
{
Block block;
ColumnWithTypeAndName column1;
column1.name = "a";
column1.type = table->getDataTypeByName("a");
column1.column = column1.type->createColumn();
ColumnUInt64::Container_t & vec1 = typeid_cast<ColumnUInt64&>(*column1.column).getData();
vec1.resize(rows);
for (size_t i = 0; i < rows; ++i)
vec1[i] = i;
block.insert(column1);
ColumnWithTypeAndName column2;
column2.name = "b";
column2.type = table->getDataTypeByName("b");
column2.column = column2.type->createColumn();
ColumnUInt8::Container_t & vec2 = typeid_cast<ColumnUInt8&>(*column2.column).getData();
vec2.resize(rows);
for (size_t i = 0; i < rows; ++i)
vec2[i] = i * 2;
block.insert(column2);
BlockOutputStreamPtr out = table->write({}, {});
out->write(block);
}
/// читаем из неё
{
Names column_names;
column_names.push_back("a");
column_names.push_back("b");
QueryProcessingStage::Enum stage;
BlockInputStreamPtr in = table->read(column_names, 0, Context{}, Settings(), stage)[0];
Block sample;
{
ColumnWithTypeAndName col;
col.type = std::make_shared<DataTypeUInt64>();
sample.insert(col);
}
{
ColumnWithTypeAndName col;
col.type = std::make_shared<DataTypeUInt8>();
sample.insert(col);
}
WriteBufferFromOStream out_buf(std::cout);
LimitBlockInputStream in_limit(in, 10, 0);
RowOutputStreamPtr output_ = std::make_shared<TabSeparatedRowOutputStream>(out_buf, sample);
BlockOutputStreamFromRowOutputStream output(output_);
copyData(in_limit, output);
}
return 0;
}
catch (const DB::Exception & e)
{
std::cerr << e.what() << ", " << e.displayText() << std::endl;
return 1;
}