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Steven Murray authored
Added the new method Rset::isEmpty() - I am guessing that the migration work of Michael would have loved to have had this method
Steven Murray authoredAdded the new method Rset::isEmpty() - I am guessing that the migration work of Michael would have loved to have had this method
Rset.hpp 6.48 KiB
/*
* The CERN Tape Archive (CTA) project
* Copyright (C) 2015 CERN
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "common/optional.hpp"
#include "rdbms/InvalidResultSet.hpp"
#include <memory>
#include <stdint.h>
#include <string>
namespace cta {
namespace rdbms {
namespace wrapper {
class RsetWrapper;
}
/**
* A wrapper around an object that iterators over a result set from the
* execution of a database query.
*
* This wrapper permits the user of the rdbms::Stmt::executeQuery() method to
* use different result set implementations whilst only using a result set type.
*/
class Rset {
public:
/**
* Constructor.
*/
Rset();
/**
* Constructor.
*
* @param impl The object actually implementing this result set.
*/
Rset(std::unique_ptr<wrapper::RsetWrapper> impl);
/**
* Deletion of copy constructor.
*/
Rset(const Rset &) = delete;
/**
* Move constructor.
*
* @param other The other object to be moved.
*/
Rset(Rset &&other);
/**
* Deletion of copy assignment.
*/ Rset &operator=(const Rset &) = delete;
/**
* Move assignment.
*/
Rset &operator=(Rset &&rhs);
/**
* Returns the SQL statement.
*
* @return The SQL statement.
*/
const std::string &getSql() const;
/**
* Attempts to get the next row of the result set.
*
* @return True if a row has been retrieved else false if there are no more
* rows in the result set.
* @throw InvalidResultSet if the result is invalid.
*/
bool next();
/**
* Returns true if the result set does not contain any more rows.
* @return True if the result set does not contain any more rows.
*/
bool isEmpty() const;
/**
* Returns true if the specified column contains a null value.
*
* @param colName The name of the column.
* @return True if the specified column contains a null value.
* @throw InvalidResultSet if the result is invalid.
*/
bool columnIsNull(const std::string &colName) const;
/**
* Returns the value of the specified column as a binary string (byte array).
*
* This method will throw an exception if the value of the specified column
* is nullptr.
*
* @param colName The name of the column.
* @return The string value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
std::string columnBlob(const std::string &colName) const;
/**
* Returns the value of the specified column as a string.
*
* This method will throw an exception if the value of the specified column
* is nullptr.
*
* @param colName The name of the column.
* @return The string value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
std::string columnString(const std::string &colName) const;
/**
* Returns the value of the specified column as a string.
*
* This method will return a null column value as an optional with no value.
*
* @param colName The name of the column.
* @return The string value of the specified column.
* @throw InvalidResultSet if the result is invalid. */
optional<std::string> columnOptionalString(const std::string &colName) const;
/**
* Returns the value of the specified column as an integer.
*
* This method will throw an exception if the value of the specified column
* is nullptr.
*
* @param colName The name of the column.
* @return The value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
uint64_t columnUint64(const std::string &colName) const;
/**
* Returns the value of the specified column as a boolean.
*
* Please note that the underlying database column type is expected to be a
* number where a non-zero value means true and a value of zero means false.
*
* This method will throw an exception if the value of the specified column
* is nullptr.
*
* @param colName The name of the column.
* @return The value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
bool columnBool(const std::string &colName) const;
/**
* Returns the value of the specified column as an integer.
*
* This method will return a null column value as an optional with no value.
*
* @param colName The name of the column.
* @return The value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
optional<uint64_t> columnOptionalUint64(const std::string &colName) const;
/**
* Returns the value of the specified column as a boolean.
*
* Please note that the underlying database column type is expected to be a
* number where a non-zero value means true and a value of zero means false.
*
* This method will return a null column value as an optional with no value.
*
* @param colName The name of the column.
* @return The value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
optional<bool> columnOptionalBool(const std::string &colName) const;
/**
* Returns the value of the specified column as a double.
*
* This method will throw an exception if the value of the specified column
* is nullptr.
*
* @param colName The name of the column.
* @return The value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
double columnDouble(const std::string &colName) const;
/**
* Returns the value of the specified column as a double.
* * This method will return a null column value as an optional with no value.
*
* @param colName The name of the column.
* @return The value of the specified column.
* @throw InvalidResultSet if the result is invalid.
*/
optional<double> columnOptionalDouble(const std::string &colName) const;
private:
/**
* The object actually implementing this result set.
*/
std::unique_ptr<wrapper::RsetWrapper> m_impl;
}; // class Rset
} // namespace rdbms
} // namespace cta