SQL filter

In some situation I needed more complicated filter and hence the method in DibiFluentDataSource.php

`
/**
* Filter by keyword
* @param Filter\FilterText $filter
* @return void
*/
public function applyFilterText(Filter\FilterText $filter)
{
$condition = $filter->getCondition();
$driver = $this->data_source->getConnection()->getDriver();
$or = [];

	foreach ($condition as $column => $value) {
                    if (class_exists(Dibi\Helpers::class) === TRUE) {

I modified for
/**
* Filter by keyword
* @param Filter\FilterText $filter
* @return void
*/
public function applyFilterText(Filter\FilterText $filter)
{
$condition = $filter->getCondition();
$driver = $this->data_source->getConnection()->getDriver();
$or = [];

	foreach ($condition as $column => $value) {
                    if (substr($column, 0 ,4) == '%sql') {
                            $column = substr($column, 4);
                    } elseif (class_exists(Dibi\Helpers::class) === TRUE) {

`

Which allows in the function
addFilterText(column_name, text, [search_column_names])
parameters search_column_names in form '%sql.....' and sql expression that is verified against the text

Start in DibiFluentDataSource.php at applyFilterText() and inspect how Filter\FilterText conditions are processed. Trace the existing addFilterText(column_name, text, [search_column_names]) usage and the proposed %sql-prefixed expressions. Done means the SQL expressions are accepted and checked against the text without breaking the existing filter behavior.