Bp_Search_Posts::sql( $search_term,  $only_totalrow_count = false )

		public function sql( $search_term, $only_totalrow_count=false ){
			/* an example UNION query :-
			-----------------------------------------------------
			(
				SELECT
					wp_posts.id , 'posts' as type, wp_posts.post_title LIKE '%ho%' AS relevance, wp_posts.post_date as entry_date
				FROM
					wp_posts
				WHERE
					1=1
					AND (
							(
									(wp_posts.post_title LIKE '%ho%')
								OR 	(wp_posts.post_content LIKE '%ho%')
							)
						)
					AND wp_posts.post_type IN ('post', 'page', 'attachment')
					AND (
						wp_posts.post_status = 'publish'
						OR wp_posts.post_author = 1
						AND wp_posts.post_status = 'private'
					)
			)
			----------------------------------------------------
			*/
			global $wpdb;

			$bp_prefix = bp_core_get_table_prefix();

			$query_placeholder = array();

			$sql = " SELECT ";

			if( $only_totalrow_count ){
				$sql .= " COUNT( DISTINCT id ) ";
			} else {
				$sql .= " DISTINCT id , %s as type, post_title LIKE %s AS relevance, post_date as entry_date  ";
				$query_placeholder[] = $this->search_type;
				$query_placeholder[] = '%'. $search_term .'%';
			}

			$sql .= " FROM {$wpdb->posts} p ";


			/* ++++++++++++++++++++++++++++++++
			 * wp_posts table fields
			 +++++++++++++++++++++++++++++++ */
			$taxonomies = get_object_taxonomies( $this->pt_name );
			foreach ( $taxonomies as $taxonomy ) {
				if ( bp_is_search_post_type_taxonomy_enable( $taxonomy, $this->pt_name ) ) {
					$tax[] = $taxonomy;
				}
			}

			//Tax query left join
			if ( ! empty( $tax ) ) {
				$sql .= " LEFT JOIN {$wpdb->term_relationships} r ON p.ID = r.object_id ";
			}

			//WHERE
			$sql .= " WHERE 1=1 AND ( p.post_title LIKE %s OR {$bp_prefix}bp_strip_tags(p.post_content) LIKE %s ";
			$query_placeholder[] = '%'. $search_term .'%';
			$query_placeholder[] = '%'. $search_term .'%';

			//Tax query
			if ( ! empty( $tax ) ) {

				$tax_in_arr = array_map( function( $t_name ) {
					return "'" . $t_name . "'";
				}, $tax );

				$tax_in = implode( ', ', $tax_in_arr );

				$sql .= " OR  r.term_taxonomy_id IN (SELECT tt.term_taxonomy_id FROM {$wpdb->term_taxonomy} tt INNER JOIN {$wpdb->terms} t ON 
					  t.term_id = tt.term_id WHERE ( t.slug LIKE %s OR t.name LIKE %s ) AND  tt.taxonomy IN ({$tax_in}) )";
					$query_placeholder[] = '%'. $search_term .'%';
					$query_placeholder[] = '%'. $search_term .'%';
			}

			//Meta query
			if ( bp_is_search_post_type_meta_enable($this->pt_name) ) {
				$sql .= " OR p.ID IN (SELECT post_id FROM {$wpdb->postmeta} WHERE {$bp_prefix}bp_strip_tags(meta_value) LIKE %s )";
				$query_placeholder[] = '%'. $search_term .'%';
			}

			//Post should be publish
			$sql .= ") AND p.post_type = '{$this->pt_name}' AND p.post_status = 'publish' ";

			$sql = $wpdb->prepare( $sql, $query_placeholder );

            return apply_filters(
                'Bp_Search_Posts_sql',
                $sql,
                array(
                    'search_term'           => $search_term,
                    'only_totalrow_count'   => $only_totalrow_count,
                )
            );
		}