ClickHouse/dbms/src/Storages/StorageSystemDatabases.cpp
2012-08-02 17:33:31 +00:00

42 lines
1.1 KiB
C++

#include <DB/Columns/ColumnString.h>
#include <DB/DataTypes/DataTypeString.h>
#include <DB/DataStreams/OneBlockInputStream.h>
#include <DB/Storages/StorageSystemDatabases.h>
namespace DB
{
StorageSystemDatabases::StorageSystemDatabases(const std::string & name_, const Context & context_)
: name(name_), context(context_)
{
columns.push_back(NameAndTypePair("name", new DataTypeString));
}
BlockInputStreams StorageSystemDatabases::read(
const Names & column_names, ASTPtr query, QueryProcessingStage::Enum & processed_stage, size_t max_block_size, unsigned threads)
{
check(column_names);
processed_stage = QueryProcessingStage::FetchColumns;
Block block;
ColumnWithNameAndType col_name;
col_name.name = "name";
col_name.type = new DataTypeString;
col_name.column = new ColumnString;
block.insert(col_name);
Poco::ScopedLock<Poco::Mutex> lock(context.getMutex());
for (Databases::const_iterator it = context.getDatabases().begin(); it != context.getDatabases().end(); ++it)
col_name.column->insert(it->first);
return BlockInputStreams(1, new OneBlockInputStream(block));
}
}