pqxx::dbtransaction Class Reference
Abstract transaction base class: bracket transactions on the database. More...
#include <dbtransaction.hxx>
Inheritance diagram for pqxx::dbtransaction:
Protected Member Functions | |
| dbtransaction (connection &c) | |
 Protected Member Functions inherited from pqxx::transaction_base | |
| transaction_base (connection &c) | |
| Create a transaction (to be called by implementation classes only). More... | |
| void | register_transaction () |
| Register this transaction with the connection. More... | |
| void | close () noexcept |
| End transaction. To be called by implementing class' destructor. More... | |
| virtual void | do_commit ()=0 |
| To be implemented by derived implementation class: commit transaction. More... | |
| virtual void | do_abort ()=0 |
| To be implemented by derived implementation class: abort transaction. More... | |
| result | direct_exec (std::string_view) |
| Execute query on connection directly. More... | |
| result | direct_exec (std::shared_ptr< std::string >) |
Additional Inherited Members | |
| Public Member Functions inherited from pqxx::transaction_base | |
| transaction_base ()=delete | |
| transaction_base (transaction_base const &)=delete | |
| transaction_base & | operator= (transaction_base const &)=delete |
| virtual | ~transaction_base ()=0 |
| void | commit () |
| Commit the transaction. More... | |
| void | abort () |
| Abort the transaction. More... | |
| result | exec (std::string_view query, std::string const &desc=std::string{}) |
| Execute query. More... | |
| result | exec (std::stringstream const &query, std::string const &desc=std::string{}) |
| result | exec0 (std::string const &query, std::string const &desc=std::string{}) |
| Execute query, which should zero rows of data. More... | |
| row | exec1 (std::string const &query, std::string const &desc=std::string{}) |
| Execute query returning a single row of data. More... | |
| result | exec_n (result::size_type rows, std::string const &query, std::string const &desc=std::string{}) |
| Execute query, expect given number of rows. More... | |
| template<typename TYPE > | |
| TYPE | query_value (std::string const &query, std::string const &desc=std::string{}) |
| Execute query, expecting exactly 1 row with 1 field. More... | |
| template<typename... TYPE> | |
| auto | stream (std::string_view query) |
| Execute a query, and loop over the results row by row. More... | |
| connection & | conn () const |
| The connection in which this transaction lives. More... | |
| void | set_variable (std::string_view var, std::string_view value) |
| Set session variable using SQL "SET" command. More... | |
| std::string | get_variable (std::string_view) |
| Read session variable using SQL "SHOW" command. More... | |
| std::string | esc (char const text[]) const |
| Escape string for use as SQL string literal in this transaction. More... | |
| std::string | esc (char const text[], std::size_t maxlen) const |
| Escape string for use as SQL string literal in this transaction. More... | |
| std::string | esc (std::string const &text) const |
| Escape string for use as SQL string literal in this transaction. More... | |
| std::string | esc (std::string_view text) const |
| Escape string for use as SQL string literal in this transaction. More... | |
| std::string | esc_raw (unsigned char const data[], std::size_t len) const |
| Escape binary data for use as SQL string literal in this transaction. More... | |
| std::string | esc_raw (std::string const &) const |
| Escape binary data for use as SQL string literal in this transaction. More... | |
| std::string | unesc_raw (std::string const &text) const |
| Unescape binary data, e.g. from a table field or notification payload. More... | |
| std::string | unesc_raw (char const *text) const |
| Unescape binary data, e.g. from a table field or notification payload. More... | |
| template<typename T > | |
| std::string | quote (T const &t) const |
| Represent object as SQL string, including quoting & escaping. More... | |
| std::string | quote_raw (unsigned char const bin[], std::size_t len) const |
| Binary-escape and quote a binarystring for use as an SQL constant. More... | |
| std::string | quote_raw (std::string const &bin) const |
| std::string | quote_name (std::string_view identifier) const |
| Escape an SQL identifier for use in a query. More... | |
| std::string | esc_like (std::string const &bin, char escape_char='\\') const |
| Escape string for literal LIKE match. More... | |
| template<typename... Args> | |
| result | exec_params (std::string const &query, Args &&... args) |
| Execute an SQL statement with parameters. More... | |
| template<typename... Args> | |
| row | exec_params1 (std::string const &query, Args &&... args) |
| template<typename... Args> | |
| result | exec_params0 (std::string const &query, Args &&... args) |
| template<typename... Args> | |
| result | exec_params_n (std::size_t rows, std::string const &query, Args &&... args) |
| template<typename... Args> | |
| result | exec_prepared (std::string const &statement, Args &&... args) |
| Execute a prepared statement, with optional arguments. More... | |
| template<typename... Args> | |
| result | exec_prepared (zview statement, Args &&... args) |
| template<typename... Args> | |
| row | exec_prepared1 (std::string const &statement, Args &&... args) |
| Execute a prepared statement, and expect a single-row result. More... | |
| template<typename... Args> | |
| row | exec_prepared1 (zview statement, Args &&... args) |
| template<typename... Args> | |
| result | exec_prepared0 (std::string const &statement, Args &&... args) |
| Execute a prepared statement, and expect a result with zero rows. More... | |
| template<typename... Args> | |
| result | exec_prepared0 (zview statement, Args &&... args) |
| template<typename... Args> | |
| result | exec_prepared_n (result::size_type rows, std::string const &statement, Args &&... args) |
| Execute a prepared statement, expect a result with given number of rows. More... | |
| template<typename... Args> | |
| result | exec_prepared_n (result::size_type rows, zview statement, Args &&... args) |
| void | process_notice (char const msg[]) const |
| Have connection process a warning message. More... | |
| void | process_notice (std::string const &msg) const |
| Have connection process a warning message. More... | |
| Public Member Functions inherited from pqxx::internal::namedclass | |
| namedclass (std::string_view classname) | |
| namedclass (std::string_view classname, std::string_view name) | |
| namedclass (std::string_view classname, char const name[]) | |
| namedclass (std::string_view classname, std::string &&name) | |
| std::string const & | name () const noexcept |
| Object name, or the empty string if no name was given. More... | |
| std::string const & | classname () const noexcept |
| Class name. More... | |
| std::string | description () const |
| Combination of class name and object name; or just class name. More... | |
Detailed Description
Abstract transaction base class: bracket transactions on the database.
Use a dbtransaction-derived object such as "work" (transaction<>) to enclose operations on a database in a single "unit of work." This ensures that the whole series of operations either succeeds as a whole or fails completely. In no case will it leave half-finished work behind in the database.
Once processing on a transaction has succeeded and any changes should be allowed to become permanent in the database, call commit(). If something has gone wrong and the changes should be forgotten, call abort() instead. If you do neither, an implicit abort() is executed at destruction time.
It is an error to abort a transaction that has already been committed, or to commit a transaction that has already been aborted. Aborting an already aborted transaction or committing an already committed one is allowed, to make error handling easier. Repeated aborts or commits have no effect after the first one.
Database transactions are not suitable for guarding long-running processes. If your transaction code becomes too long or too complex, consider ways to break it up into smaller ones. Unfortunately there is no universal recipe for this.
The actual operations for committing/aborting the backend transaction are implemented by a derived class. The implementing concrete class must also call close() from its destructor.
Constructor & Destructor Documentation
◆ dbtransaction()
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explicitprotected |
The documentation for this class was generated from the following file:
