sqlite_open(3) [php man page]

SQLITE_OPEN(3)															    SQLITE_OPEN(3)

sqlite_open - Opens an SQLite database and create the database if it does not exist

SYNOPSIS

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

DESCRIPTION

       Object oriented style (constructor): SQLiteDatabase::__construct (string  $filename, [int  $mode = 0666], [string  &$error_message])

	Opens an SQLite database or creates the database if it does not exist.

PARAMETERS

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

	      o $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.

	      o $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.

RETURN VALUES

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

EXAMPLES

       Example #1

	      sqlite_open(3) example

	      <?php
	      if ($db = sqlite_open('mysqlitedb', 0666, $sqliteerror)) {
		  sqlite_query($db, 'CREATE TABLE foo (bar varchar(10))');
		  sqlite_query($db, "INSERT INTO foo VALUES ('fnord')");
		  $result = sqlite_query($db, 'select bar from foo');
		  var_dump(sqlite_fetch_array($result));
	      } else {
		  die($sqliteerror);
	      }
	      ?>

NOTES

       Tip

	       On Unix platforms, SQLite is sensitive to scripts that use the fork() system call. If you do have such a script, it is  recommended
	      that  you  close the handle prior to forking and then re-open it in the child and/or parent. For more information on this issue, see
	      The C language interface to the SQLite library in the section entitled Multi-Threading And SQLite.

       Tip

	       It is not recommended to work with SQLite databases mounted on NFS partitions. Since NFS is notoriously bad when it comes to  lock-
	      ing you may find that you cannot even open the database at all, and if it succeeds, the locking behaviour may be undefined.

       Note

	       Starting  with  SQLite library version 2.8.2, you can specify :memory: as the $filename to create a database that lives only in the
	      memory of the computer. This is useful mostly for temporary processing, as the in-memory database will be destroyed when the process
	      ends.  It  can  also  be	useful when coupled with the ATTACH DATABASE SQL statement to load other databases and move and query data
	      between them.

       Note

	       SQLite is safe mode and open_basedir aware.

SEE ALSO

       sqlite_popen(3), sqlite_close(3), sqlite_factory(3).

PHP Documentation Group 													    SQLITE_OPEN(3)

SQLITE_CREATE_AGGREGATE(3)												SQLITE_CREATE_AGGREGATE(3)

sqlite_create_aggregate - Register an aggregating UDF for use in SQL statements

SYNOPSIS

       void  sqlite_create_aggregate (resource	$dbhandle, string  $function_name, callable  $step_func, callable  $finalize_func, [int  $num_args
       = -1])

DESCRIPTION

       Object oriented style (method): void SQLiteDatabase::createAggregate  (string   $function_name,	callable   $step_func,	callable   $final-
       ize_func, [int  $num_args = -1])

       sqlite_create_aggregate(3)  is  similar	to  sqlite_create_function(3)  except  that it registers functions that can be used to calculate a
       result aggregated across all the rows of a query.

	The key difference between this function and sqlite_create_function(3) is that	two  functions	are  required  to  manage  the	aggregate;
       $step_func  is called for each row of the result set. Your PHP function should accumulate the result and store it into the aggregation con-
       text. Once all the rows have been processed, $finalize_func will be called and it should then take the data from  the  aggregation  context
       and return the result. Callback functions should return a type understood by SQLite (i.e. scalar type).

PARAMETERS

	      o $dbhandle
		- The SQLite Database resource; returned from sqlite_open(3) when used procedurally. This parameter is not required when using the
		object-oriented method.

	      o $function_name
		- The name of the function used in SQL statements.

	      o $step_func
		- Callback function called for each row of the result set. Function parameters are &$context, $value, ....

	      o $finalize_func
		- Callback function to aggregate the "stepped" data from each row. Function parameter is &$context and the function should  return
		the final result of aggregation.

	      o $num_args
		- Hint to the SQLite parser if the callback function accepts a predetermined number of arguments.

RETURN VALUES

	No value is returned.

EXAMPLES

       Example #1

	      max_length aggregation function example

	      <?php
	      $data = array(
		 'one',
		 'two',
		 'three',
		 'four',
		 'five',
		 'six',
		 'seven',
		 'eight',
		 'nine',
		 'ten',
		 );
	      $dbhandle = sqlite_open(':memory:');
	      sqlite_query($dbhandle, "CREATE TABLE strings(a)");
	      foreach ($data as $str) {
		  $str = sqlite_escape_string($str);
		  sqlite_query($dbhandle, "INSERT INTO strings VALUES ('$str')");
	      }

	      function max_len_step(&$context, $string)
	      {
		  if (strlen($string) > $context) {
		      $context = strlen($string);
		  }
	      }

	      function max_len_finalize(&$context)
	      {
		  return $context;
	      }

	      sqlite_create_aggregate($dbhandle, 'max_len', 'max_len_step', 'max_len_finalize');

	      var_dump(sqlite_array_query($dbhandle, 'SELECT max_len(a) from strings'));

	      ?>

	In this example, we are creating an aggregating function that will calculate the length of the longest string in one of the columns of the
       table. For each row, the max_len_step function is called and passed a $context parameter. The context parameter is just like any other  PHP
       variable  and  be  set to hold an array or even an object value. In this example, we are simply using it to hold the maximum length we have
       seen so far; if the $string has a length longer than the current maximum, we update the context to hold this new maximum length.

	After all of the rows have been processed, SQLite calls the max_len_finalize function to determine the aggregate result.  Here,  we  could
       perform some kind of calculation based on the data found in the $context. In our simple example though, we have been calculating the result
       as the query progressed, so we simply need to return the context value.

       Note

	       The example  above  will  not  work  correctly  if  the	column	contains  binary  data.  Take  a  look	at  the  manual  page  for
	      sqlite_udf_decode_binary(3) for an explanation of why this is so, and an example of how to make it respect the binary encoding.

       Tip

	       It  is  NOT  recommended  for you to store a copy of the values in the context and then process them at the end, as you would cause
	      SQLite to use a lot of memory to process the query - just think of how much memory you would need if a million rows were	stored	in
	      memory, each containing a string 32 bytes in length.

       Tip

	       You can use sqlite_create_function(3) and sqlite_create_aggregate(3) to override SQLite native SQL functions.

SEE ALSO

       sqlite_create_function(3), sqlite_udf_encode_binary(3), sqlite_udf_decode_binary(3).

PHP Documentation Group 												SQLITE_CREATE_AGGREGATE(3)