GncDbiSqlConnection Class Reference

Encapsulate a libdbi dbi_conn connection. More...

#include <gnc-dbisqlconnection.hpp>

Inheritance diagram for GncDbiSqlConnection:

Public Member Functions
	GncDbiSqlConnection (DbType type, QofBackend *qbe, dbi_conn conn, SessionOpenMode mode)
GncSqlResultPtr	execute_select_statement (const GncSqlStatementPtr &) noexcept override
int	execute_nonselect_statement (const GncSqlStatementPtr &) noexcept override
	Returns false if error.
GncSqlStatementPtr	create_statement_from_sql (const std::string &) const noexcept override
bool	does_table_exist (const std::string &) const noexcept override
	Returns true if successful.
bool	begin_transaction () noexcept override
	Returns TRUE if successful, false if error.
bool	rollback_transaction () noexcept override
	Returns TRUE if successful, FALSE if error.
bool	commit_transaction () noexcept override
	Returns TRUE if successful, FALSE if error.
bool	create_table (const std::string &, const ColVec &) const noexcept override
	Returns TRUE if successful, FALSE if error.
bool	create_index (const std::string &, const std::string &, const EntryVec &) const noexcept override
	Returns TRUE if successful, FALSE if error.
bool	add_columns_to_table (const std::string &, const ColVec &) const noexcept override
	Returns TRUE if successful, FALSE if error.
std::string	quote_string (const std::string &) const noexcept override
int	dberror () const noexcept override
	Get the connection error value. More...
QofBackend *	qbe () const noexcept
dbi_conn	conn () const noexcept
void	set_error (QofBackendError error, unsigned int repeat, bool retry) noexcept override
void	init_error () noexcept
bool	verify () noexcept override
	Check if the dbi connection is valid. More...
bool	retry_connection (const char *msg) noexcept override
bool	table_operation (TableOpType op) noexcept
	Perform a specified SQL operation on every table in a database. More...
std::string	add_columns_ddl (const std::string &table_name, const ColVec &info_vec) const noexcept
bool	drop_indexes () noexcept
Public Member Functions inherited from GncSqlConnection
virtual	~GncSqlConnection ()=default
	Returns NULL if error.

Detailed Description

Encapsulate a libdbi dbi_conn connection.

Definition at line 41 of file gnc-dbisqlconnection.hpp.

Member Function Documentation

dberror()

int GncDbiSqlConnection::dberror ( ) const

inlineoverridevirtualnoexcept

Get the connection error value.

If not 0 will normally be meaningless outside of implementation code.

Implements GncSqlConnection.

Definition at line 63 of file gnc-dbisqlconnection.hpp.

                                          {
        return dbi_conn_error(m_conn, nullptr); }

table_operation()

bool GncDbiSqlConnection::table_operation ( TableOpType  op )

noexcept

Perform a specified SQL operation on every table in a database.

Possible operations are:

• drop: to DROP all tables from the database
• empty: to DELETE all records from each table in the database.
• backup: Rename every table from "name" to "name_back"
• drop_backup: DROP the backup tables.
• rollback: DROP the new table "name" and rename "name_back" to "name", restoring the database to its previous state.

The intent of the last two is to be able to move an existing table aside, query its contents with a transformation (in 2.4.x this is already done as the contents are loaded completely when a Qof session is started), save them to a new table according to a new database format, and finally drop the backup table; if there's an error during the process, rollback allows returning the table to its original state.

Parameters

sql_conn	The sql connection (via dbi) to which the transactions will be sent
table_namess	StrVec of tables to operate on.
op	The operation to perform.

Returns

Success (TRUE) or failure.

Definition at line 671 of file gnc-dbisqlconnection.cpp.

{
    auto backup_tables = m_provider->get_table_list(m_conn, "%_back");
    auto all_tables = m_provider->get_table_list(m_conn, "");
    /* No operations on the lock table */
    auto new_end = std::remove(all_tables.begin(), all_tables.end(), lock_table);
    all_tables.erase(new_end, all_tables.end());
    StrVec data_tables;
    data_tables.reserve(all_tables.size() - backup_tables.size());
    std::set_difference(all_tables.begin(), all_tables.end(),
                        backup_tables.begin(), backup_tables.end(),
                        std::back_inserter(data_tables));
    switch(op)
    {
    case backup:
        if (!backup_tables.empty())
        {
            PERR("Unable to backup database, an existing backup is present.");
            qof_backend_set_error(m_qbe, ERR_BACKEND_DATA_CORRUPT);
            return false;
        }
        for (auto table : data_tables)
            if (!rename_table(table, table +"_back"))
                return false; /* Error, trigger rollback. */
        break;
    case drop_backup:
        for (auto table : backup_tables)
        {
            auto data_table = table.substr(0, table.find("_back"));
            if (std::find(data_tables.begin(), data_tables.end(),
                          data_table) != data_tables.end())
                drop_table(table); /* Other table exists, OK. */
            else /* No data table, restore the backup */
                rename_table(table, data_table);
        }
        break;
    case rollback:
        for (auto table : backup_tables)
        {
            auto data_table = table.substr(0, table.find("_back"));
            if (std::find(data_tables.begin(), data_tables.end(),
                          data_table) != data_tables.end())
                drop_table(data_table); /* Other table exists, OK. */
            rename_table(table, data_table);
        }
        break;
    case recover:
        for (auto table : backup_tables)
        {
            auto data_table = table.substr(0, table.find("_back"));
            if (std::find(data_tables.begin(), data_tables.end(),
                          data_table) != data_tables.end())
            {
                if (!merge_tables(data_table, table))
                    return false;
            }
            else
            {
                if (!rename_table(table, data_table))
                    return false;
            }
        }
        break;
    }
   return true;
}

verify()

bool GncDbiSqlConnection::verify ( )

overridevirtualnoexcept

Check if the dbi connection is valid.

If not attempt to re-establish it Returns TRUE if there is a valid connection in the end or FALSE otherwise

Implements GncSqlConnection.

Definition at line 558 of file gnc-dbisqlconnection.cpp.

{
    if (m_conn_ok)
        return true;

    /* We attempt to connect only once here. The error function will
     * automatically re-attempt up until DBI_MAX_CONN_ATTEMPTS time to connect
     * if this call fails.  After all these attempts, conn_ok will indicate if
     * there is a valid connection or not.
     */
    init_error ();
    m_conn_ok = true;
    (void)dbi_conn_connect (m_conn);

    return m_conn_ok;
}

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The documentation for this class was generated from the following files:

• gnc-dbisqlconnection.hpp
• gnc-dbisqlconnection.cpp