How to change the SQL query in views?

Hello, I need to modify a views query.

I'm using hook_views_query_alter 

function custom_module_views_query_alter(&$view, &$query) {
     if ( $view->name == 'uc_catalog_terms' ) {
	   $query->where[0]['conditions'][0]['field']="SUBSTRING('taxonomy_term_data.name, 1, 1)";
  }
}

However, the query removes all characters, resulting in views making the following query:

WHERE (( (SUBSTRINGtaxonomy_term_data.name11 = 'a') ))

Why are the characters being removed, and how can I address this?

 I found on a foreign forum that the error was in version 7x.3.dev,

I am using version 7.x-3.7