Scenario: You have dynamic checkboxes (multi-select) or radio buttons on your search form and after the search is complete, you want to redisplay the search form with your choices still selected.

Issue: Normally this is easy because you just set the field's default value to [get param="

Dynamic fields in search form - display choices after search

Solution:

1. In the form settings, I added two new parameters to the URL, one for the ids of the checkboxes and one for the ids of the radio box. When doing this, use the following syntax [125 show="id"] where 125 is the field id.
2. In the form’s After Fields section, add this jQuery script to use those new parameters and “manually” set the checkboxes and radio buttons. Replace 125 with the ID of your radio button and 124 with the ID of your checkbox. You should also change the variable names so they make sense with your application.

There have been many times I've wanted to get data from a form and the existing formidable APIs (at least the ones that I know of) don't get me there.  Also, there are times when I'm using Datatables and I want to create a view from a SQL select so that I can use server-side processing.  The following code snippet can take a list of fields and column names (and additional where items) and generate that nasty-looking SQL command that you need for this.

DISCLAIMER: There's no error-checking and there are several ways it could've been written to be more flexible, but I didn't have unlimited time :).

HINT: The output will be messy.  You can feed it through an online syntax checker to see it in a nicely formatted way.

/**
  * Name: ff_buildGetObjectSQL
  * Author: Rob LeVine
  * Description: Creates a big SQL query to get any/all of the item meta values of fields across all items (potentially limited by an additional where)
  * 
  * Parameters:
  *  $fields - array of field ids and column names, e.g., $fields = array( array("id"=>"load_id"), array("name"=>"company_name"),  ... )
  *  $addlWhere - array operators, field ids and values, e.g.,  $addlWhere = array(array("operator" => "AND", field_id" => $load_field_id, "value" => $value));  
  *  $order_by - order conditionm e.g., "created_date DESC"
  * 
  * Return: string (sql command)
  * Assumptions:  
  *    1. All the fields in $fields are in the same form, i.e., attached to the same item
  *    2. The field in $addlWhere has to be in $fields as well
  *
  */

function ff_buildGetObjectSQL($fields, 
			      $addlWhere=null, 
			      $order_by=null) {
    global $wpdb;
	
    $wpdb_prefix = $wpdb->prefix;
    $table_item_metas = $wpdb_prefix . 'frm_item_metas';

    $select = "SELECT ";
    $from ="FROM ";
    $count = count($fields);
    for($i=0;$i<$count-1;$i++) {
	$from .= "(";
    }
    $where = " WHERE ";
    $firsttime = true;
	foreach($fields as $field) {
		$field_id = $field["field_id"];
		$select .= "t" . $field_id . ".meta_value AS " . $field["column_name"] . ",";
		if ($firsttime) {
			$mainFieldId = $field_id;
			$mainField = "t" . $field_id;
			$from .= "$table_item_metas $mainField";
			$firsttime = false;
		}
		else{
			$from .= " LEFT JOIN $table_item_metas t"  .  $field_id . " ON (t" . $field_id . ".item_id = $mainField.item_id AND t" . $field_id . ".field_id = " . $field_id. "))";
		}
	}
	// remove excess string and space
	$select = substr($select, 0, -1);
	$sql = "$select $from";
	$where .= " $mainField.field_id = $mainFieldId ";
	if (isset($addlWhere)) {
		foreach($addlWhere as $singleWhere) {
			$where .= " " . $singleWhere["operator"] . " t" . $singleWhere['field_id'] . ".meta_value = " . $singleWhere['value'];
		}
	}
	$sql .= $where;
	if (isset($order_by)) {
		$sql .= " ORDER BY $order_by";
	}
	
	return $sql;
}