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plugin:sqlite

sqlite Plugin

Compatible with DokuWiki

  • 2015-08-10 "Detritus" yes
  • 2014-09-29 "Hrun" yes
  • 2014-05-05 "Ponder Stibbons" yes
  • 2013-12-08 "Binky" yes

plugin A helper plugin to easily access a SQLite database

Last updated on
2016-03-23
Provides
Helper
Repository
Source

Tagged with database, sqlite

A CosmoCode Plugin

Requirements

This plugin needs SQLite support in your PHP installation. It can work either with the sqlite extension to access and create SQLite Version 2 databases or the the pdo-sqlite extension for accessing and creating SQLite Version 3 databases. If both extensions are available, pdo-sqlite will be used.

Important Upgrade Info: older versions of this plugin supported sqlite2 only. If your system has both extensions installed, the plugin will switch to sqlite3 and your databases need to be converted to the new format. Here's how to do that:

  • Go to the Admin screen
  • Select “SQLite Access”
  • Pick a sqlite2 data base
  • Click the “convert format” button

Download and Installation

Install the plugin using the Plugin Manager and the download URL above, which points to latest version of the plugin. Refer to Plugins on how to install plugins manually.

Changes

Admin Interface

Admin Interface

The plugin comes with a simple admin interface where you can run your own SQL queries against any of the available databases.

Available databases (data/meta/*.sqlite and data/meta/*.sqlite3) are shown in the Table of Contents. Select one and you can submit your own queries.

Developer Information

To use this helper plugin in your own plugins, load it and call the init() function to connect to the database. Make sure you check if the plugin was loaded correctly and if the init() function ran without error, before executing your own code.

// load the helper plugin
/** @var helper_plugin_sqlite $sqlite */
$sqlite = plugin_load('helper', 'sqlite');
if(!$sqlite){
    msg('This plugin requires the sqlite plugin. Please install it', -1);
    return;
}
// initialize the database connection
if(!$sqlite->init('myplugin',DOKU_PLUGIN.'myplugin/db/')){
    return;
}
// use the plugin
$res = $sqlite->query("SELECT * FROM mytable");
$arr = $sqlite->res2arr($res);
print_r($arr);

Functions

init

Initializes and opens the database. Needs to be called right after loading this helper plugin

  • $dbname is the name of the database.
  • $updatedir is a path where update SQL files are located (see below)

Returns boolean whether it succeed.

$succeed = $plugin->init($dbname,$updatedir);

storeEntry

Convenience function to run an INSERT OR REPLACE operation

The function takes a key-value array with the column names in the key and the actual value in the value, build the appropriate query and executes it.

  • $table - the table the entry should be saved to (will not be escaped)
  • $entry - A simple key-value pair array (only values will be escaped)

Returns false or result object

$res = $plugin->storeEntry($table, $entry)

query

Execute a query with the given parameters.

Takes care of escaping

  • $sql - the statement
  • arguments…
    • Arguments can also be given as a single array

Returns false or result object

$res = $plugin->query($sql[,arg1[,arg2[...]]]);

countChanges

Count the number of records changed last time

Don't work after a SELECT statement

  • $res - a query result

Returns integer count

$count = $plugin->countChanges($res);

res2count

Count the number of records in result

This function is really inperformant in PDO and should be avoided!

  • $res - a query result

Returns integer count

$count = $plugin->res2count($res);

res2arr

Returns a complete result set as array

  • $res - a query result
  • $assoc - associated or numbered index array

Returns false or array with result

$rows = $plugin->res2arr($res[,$assoc]){

Returns default an associated array, with column names as indexes. If $assoc = false it returns an array indexed by column number (0-indexed).

res2row

Return the next row from a given result set as associative array

  • $res - the result from a query
  • $numrow - wanted row number of result set (Not supported by current backends)

Returns false or array with result

$row = $plugin->res2row($res[, $rownum=0])

res_fetch_array

Fetch the next row as zero indexed array

  • $res - the result from a query

Returns false or zero indexed array

$row = $plugin->res_fetch_array($res)

res_fetch_assoc

Fetch the next row as assocative array

  • $res - the result from a query

Returns false or array with column names as index

$row = $plugin->res_fetch_assoc($res)

res2single

Return the first value from the next row

  • $res - the result from a query

Returns false or string result value

$value = $plugin->res2single($res){

quote and join

Join the given values and quote them for SQL insertion

  • $vals - values to join
  • $sep - separator char

Returns joined and quoted string

$string = $plugin->quote_and_join($vals,$sep=',');

quote string

Escape the given string and surround it with quotes

$string = $plugin->quote_string($string);

Escape string

Escape string for sql

$string = $plugin->escape_string($string);

close result set

Closes the result set (and it's cursors)

If you're doing SELECT queries inside a TRANSACTION, be sure to call this function on all your results sets, before COMMITing the transaction.

Also required when not all rows of a result are fetched

  • $res - the result from a query
$succeed = $plugin->res_close($res);

create_function

Registers a User Defined Function for use in SQL statements

  • $function_name - name of the function used in SQL statements.
  • $callback - callback function to handle the defined SQL function. (Should return a type understood by SQLite (i.e. scalar type))
  • $num_args - Hint to the SQLite parser if the callback function accepts a predetermined number of arguments.

Returns true on succes, false on failure.

$succeed = $plugin->create_function($function_name, $callback, $num_args)

DB Schema Setup/Update Mechanism

Your plugin will need to create a database schema and maybe fill it with some initial data. When you release new versions of your plugin you might need to update the schema. The sqlite plugin provides a simple mechanism to do so.

This is all handled within the init() function. The second parameter has to point to a directory where your SQL files are located. Each file correspondents to a certain database version. Version 1 is the very first setup that is done when the database is created. Each subsequent version is then applied above the previous version.

The number of the most recent version has to be stored in a file called latest.version. The update files it self have to be named updateXXXX.sql where XXXX is a zero-padded 4 digit number, starting with 0001.

The update mechanism will wrap the execution of each update in a transaction, you need not to do that yourself. If an update fails, the transaction is rolled back and the update is aborted.

The sqlite plugin keeps track of the version a database is in currently using a table called opts. You may not have a table named like that!

SQL Extensions

The plugin provides a few additional features over the standard SQLite syntax.

ALTER TABLE

The plugin supports a simplified ALTER TABLE syntax. This is probably most useful in the update mechanism. The plugin emulates the alter table call by copying the affected data to a temporary table and dropping, recreating and refilling the original table. When used outside the update mechanism, it is recommended to wrap the call in a transaction.

ALTER TABLE tbl_name alter_specification [, alter_specification] ...
 
alter_specification:
    ADD column_definition
  | DROP column_definition
  | CHANGE old_col_name column_definition
 
column_definition:
    same as for create table statements

Documentation create table

Examples:

ALTER TABLE employees ADD first_name, ADD last_name
ALTER TABLE invoices ADD note text, CHANGE idate invoice_date DATETIME
ALTER TABLE foo DROP bar, ADD bar2 INTEGER
Using SQLite's native ALTER TABLE syntax

To use the native ALTER TABLE syntax of SQLite:

$plugin->getAdapter()->setUseNativeAlter(true);

The simple support in the sqlite plugin for the ALTER TABLE syntax was to overcome previous limited implementation in PHP's SQLite drivers.

GROUP_CONCAT

This GROUP_CONCAT function returns a string result with the concatenated unique values from a group.

GROUP_CONCAT(expr, str_val)

Example:

SELECT student_name, GROUP_CONCAT(test_score, ',')
FROM student
GROUP BY student_name;

First argument is just a expression. With the second argument you specifies the string value that as the separator should be inserted between group values. To eliminate the separator altogether, specify empty string ''.

GETACCESSLEVEL

Returns the integer DokuWiki permission level of a given resolved and cleaned pageid.

GETACCESSLEVEL(str_val)

Example:

// comments for page with read access
$query = "SELECT A.pid as pid, page, title, cid
            FROM entries A, comments B
           WHERE A.pid = B.pid
             AND GETACCESSLEVEL(A.page) >= ".AUTH_READ

Available permission levels are defined in inc/auth.php. Hidden pages return also the AUTH_NONE permission level.

PAGEEXISTS

Checks whether a page of given pageid exists. Returns 0 or 1.

PAGEEXISTS(str_val)

Example:

SELECT VALUE,pageid
  FROM tablename
 WHERE PAGEEXISTS(pageid) = 1

Bugs, Feature Requests and Patches

Please submit bugs and feature requests in the issue tracker. Patches should be sent unified diff format or as git patches. Or even better: fork the repository at github and send a merge request.

plugin/sqlite.txt · Last modified: 2016-03-26 18:02 by Klap-in