sqlite_popen

(PHP 5 < 5.4.0, PECL sqlite >= 1.0.0)

sqlite_popen — Opens a persistent handle to an SQLite database and create the database if it does not exist

说明

sqlite_popen ( string $filename [, int $mode = 0666 [, string &$error_message ]] ) : resource

This function behaves identically to sqlite_open() except that is uses the persistent resource mechanism of PHP. For information about the meaning of the parameters, read the sqlite_open() manual page.

sqlite_popen() will first check to see if a persistent handle has already been opened for the given filename. If it finds one, it returns that handle to your script, otherwise it opens a fresh handle to the database.

The benefit of this approach is that you don't incur the performance cost of re-reading the database and index schema on each page hit served by persistent web server SAPI's (any SAPI except for regular CGI or CLI).

Note: If you use persistent handles and have the database updated by a background process (perhaps via a crontab), and that process re-creates the database by overwriting it (either by unlinking and rebuilding, or moving the updated version to replace the current version), you may experience undefined behaviour when a persistent handle on the old version of the database is recycled. To avoid this situation, have your background processes open the same database file and perform their updates in a transaction.

参数

filename

The filename of the SQLite database. If the file does not exist, SQLite will attempt to create it. PHP must have write permissions to the file if data is inserted, the database schema is modified or to create the database if it does not exist.

mode

The mode of the file. Intended to be used to open the database in read-only mode. Presently, this parameter is ignored by the sqlite library. The default value for mode is the octal value 0666 and this is the recommended value.

error_message

Passed by reference and is set to hold a descriptive error message explaining why the database could not be opened if there was an error.

返回值

Returns a resource (database handle) on success, FALSE on error.

参见

  • sqlite_open() - Opens an SQLite database and create the database if it does not exist
  • sqlite_close() - Closes an open SQLite database
  • sqlite_factory() - Opens an SQLite database and returns an SQLiteDatabase object

相关文章
php dbase 函数 opens a databasephp direct io 函数 opens a file creating it if necessary at a lower level than the c library input/ouput stream functions allowphp enchant 函数 will return a list of values if any of those pre conditions are not metphp frontbase 函数 create a frontbase databasephp firebird/interbase 函数 open a persistent connection to an interbase databasephp informix 函数 creates an slob object and opens itphp ingres 函数 open a persistent connection to an ingres databasephp socket 函数 receives data from a socket whether or not it is connection orientedphp sqlite 函数 execute a query against a given database and returns an arrayphp sqlite 函数 opens an sqlite database and returns an sqlitedatabase objectphp sqlite 函数 opens an sqlite database and create the database if it does not existphp sqlite 函数 opens a persistent handle to an sqlite database and create the database if it does not existphp sqlite 函数 executes a query against a given database and returns a result handlephp sqlite 函数 execute a query that does not prefetch and buffer all dataphp sqlsrv 函数 opens a connection to a microsoft sql server databasephp wincache 函数 adds a variable in user cache only if variable does not already exist in the cachephp mongocollection creates an index on the specified field s if it does not already existphp mongocollection creates an index on the specified field s if it does not already existphp sqlite3 instantiates an sqlite3 object and opens an sqlite 3 databasephp sqlite3 opens an sqlite database
关注编程学问公众号