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#include <Storages/IStorage.h>
#include <Parsers/TablePropertiesQueriesASTs.h>
#include <Processors/Sources/SourceFromSingleChunk.h>
#include <QueryPipeline/BlockIO.h>
#include <DataTypes/DataTypesNumber.h>
#include <Columns/ColumnsNumber.h>
#include <Interpreters/Context.h>
#include <Interpreters/InterpreterExistsQuery.h>
#include <Access/Common/AccessFlags.h>
#include <Common/typeid_cast.h>
namespace DB
{
namespace ErrorCodes
{
extern const int SYNTAX_ERROR;
}
BlockIO InterpreterExistsQuery::execute()
{
BlockIO res;
res.pipeline = executeImpl();
return res;
}
Block InterpreterExistsQuery::getSampleBlock()
{
return Block{{
ColumnUInt8::create(),
std::make_shared<DataTypeUInt8>(),
"result" }};
}
QueryPipeline InterpreterExistsQuery::executeImpl()
{
ASTQueryWithTableAndOutput * exists_query;
bool result = false;
if ((exists_query = query_ptr->as<ASTExistsTableQuery>()))
{
if (exists_query->temporary)
{
result = static_cast<bool>(getContext()->tryResolveStorageID(
{"", exists_query->getTable()}, Context::ResolveExternal));
}
else
{
String database = getContext()->resolveDatabase(exists_query->getDatabase());
getContext()->checkAccess(AccessType::SHOW_TABLES, database, exists_query->getTable());
result = DatabaseCatalog::instance().isTableExist({database, exists_query->getTable()}, getContext());
}
}
else if ((exists_query = query_ptr->as<ASTExistsViewQuery>()))
{
String database = getContext()->resolveDatabase(exists_query->getDatabase());
getContext()->checkAccess(AccessType::SHOW_TABLES, database, exists_query->getTable());
auto table = DatabaseCatalog::instance().tryGetTable({database, exists_query->getTable()}, getContext());
result = table && table->isView();
}
else if ((exists_query = query_ptr->as<ASTExistsDatabaseQuery>()))
{
String database = getContext()->resolveDatabase(exists_query->getDatabase());
getContext()->checkAccess(AccessType::SHOW_DATABASES, database);
result = DatabaseCatalog::instance().isDatabaseExist(database);
}
else if ((exists_query = query_ptr->as<ASTExistsDictionaryQuery>()))
{
if (exists_query->temporary)
throw Exception(ErrorCodes::SYNTAX_ERROR, "Temporary dictionaries are not possible.");
String database = getContext()->resolveDatabase(exists_query->getDatabase());
getContext()->checkAccess(AccessType::SHOW_DICTIONARIES, database, exists_query->getTable());
result = DatabaseCatalog::instance().isDictionaryExist({database, exists_query->getTable()});
}
return QueryPipeline(std::make_shared<SourceFromSingleChunk>(Block{{
ColumnUInt8::create(1, result),
std::make_shared<DataTypeUInt8>(),
"result" }}));
}
}
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