sqlite_set_authorizer

Registers an authorizer for a connection.

1 if the authorizer was registered successfully, or $null if there was an error.

An authorizer lets you to examine what kind of query SQLite is trying to run, and change the behavior of the result by either denying the operation, or ignoring it. The foremost purpose of an authorizer is to allow scripts to safely execute user-entered SQL queries, without compromising security of the database.

Only one authorizer can be registered at a time for a connection. Setting a new authorizer for a connection will override the old authorizer, if one is registered. You can unregister the authorizer by passing $null for authorizer_alias.

The authorizer should return $SQLITE_OK if the current action should be allowed, $SQLITE_DENY if it should be denied (generates an error) or $SQLITE_IGNORE if it should be ignored (treated as a no-op). You can use an authorizer to make certain columns or functions return NULL by returning $SQLITE_IGNORE for the corresponding action (see below). Returning any other value than the ones previously mentioned will auto-assume $SQLITE_OK.

The authorizer alias will receive a few arguments. The first argument is the type of action SQLite is performing. The second and third argument provide additional information depending on what type of an action is in question. The fourth argument is the name of the database (eg. "main" or "temp") where applicable. The fifth argument is the name of the inner-most trigger or view that triggered the authorizer, or $null if the authorizer was triggered directly from code.

You can see all the possible types of action that authorizer can be triggered for below, and the associated arguments for it (the 2nd and 3rd arguments of the authorizer alias).

Type                          Value     2nd Arg         3rd Arg

$SQLITE_CREATE_INDEX              1     Index Name      Table Name
$SQLITE_CREATE_TABLE              2     Table Name      $null
$SQLITE_CREATE_TEMP_INDEX         3     Index Name      Table Name
$SQLITE_CREATE_TEMP_TABLE         4     Table Name      $null
$SQLITE_CREATE_TEMP_TRIGGER       5     Trigger Name    Table name
$SQLITE_CREATE_TEMP_VIEW          6     View Name       $null
$SQLITE_CREATE_TRIGGER            7     Trigger name    Table Name
$SQLITE_CREATE_VIEW               8     View Name       $null
$SQLITE_DELETE                    9     Table Name      $null
$SQLITE_DROP_INDEX               10     Index Name      Table Name
$SQLITE_DROP_TABLE               11     Table Name      $null
$SQLITE_DROP_TEMP_INDEX          12     Index Name      Table Name
$SQLITE_DROP_TEMP_TABLE          13     Table Name      $null
$SQLITE_DROP_TEMP_TRIGGER        14     Trigger Name    Table Name
$SQLITE_DROP_TEMP_VIEW           15     View Name       $null
$SQLITE_DROP_TRIGGER             16     Trigger Name    Table Name
$SQLITE_DROP_VIEW                17     View Name       $null
$SQLITE_INSERT                   18     Table Name      $null
$SQLITE_PRAGMA                   19     Pragma Name     1st Arg or $null
$SQLITE_READ                     20     Table Name      Column Name
$SQLITE_SELECT                   21     $null           $null
$SQLITE_TRANSACTION              22     $null           $null
$SQLITE_UPDATE                   23     Table Name      Column Name
$SQLITE_ATTACH                   24     Filename        $null
$SQLITE_DETACH                   25     Database Name   $null
$SQLITE_ALTER_TABLE              26     Database Name   Table Name
$SQLITE_REINDEX                  27     Index Name      $null
$SQLITE_ANALYZE                  28     Table Name      $null
$SQLITE_CREATE_VTABLE            29     Table Name      Module Name
$SQLITE_DROP_VTABLE              30     Table Name      Module Name
$SQLITE_FUNCTION                 31     Function Name   $null