system/Database/SQLite3/Connection.php
public function getFieldNames(string $table)
	{
		// Is there a cached result?
		if (isset($this->dataCache['field_names'][$table]))
		{
			return $this->dataCache['field_names'][$table];
		}

		if (empty($this->connID))
		{
			$this->initialize();
		}

		if (false === ($sql = $this->_listColumns($table)))
		{
			if ($this->DBDebug)
			{
				throw new DatabaseException(lang('Database.featureUnavailable'));
			}

			return false;
		}

		$query                                  = $this->query($sql);
		$this->dataCache['field_names'][$table] = [];

		foreach ($query->getResultArray() as $row)
		{
			// Do we know from where to get the column's name?
			if (! isset($key))
			{
				if (isset($row['column_name']))
				{
					$key = 'column_name';
				}
				elseif (isset($row['COLUMN_NAME']))
				{
					$key = 'COLUMN_NAME';
				}
				elseif (isset($row['name']))
				{
					$key = 'name';
				}
				else
				{
					// We have no other choice but to just get the first element's key.
					$key = key($row);
				}
			}

			$this->dataCache['field_names'][$table][] = $row[$key];
		}

		return $this->dataCache['field_names'][$table];
	}
public function getFieldNames(string $table)
	{
		// Is there a cached result?
		if (isset($this->dataCache['field_names'][$table]))
		{
			return $this->dataCache['field_names'][$table];
		}

		if (empty($this->connID))
		{
			$this->initialize();
		}

		if (false === ($sql = $this->_listColumns($table)))
		{
			if ($this->DBDebug)
			{
				throw new DatabaseException(lang('Database.featureUnavailable'));
			}

			return false;
		}

		$query                                  = $this->query($sql);
		$this->dataCache['field_names'][$table] = [];

		foreach ($query->getResultArray() as $row)
		{
			// Do we know from where to get the column's name?
			if (! isset($key))
			{
				if (isset($row['column_name']))
				{
					$key = 'column_name';
				}
				elseif (isset($row['COLUMN_NAME']))
				{
					$key = 'COLUMN_NAME';
				}
				elseif (isset($row['name']))
				{
					$key = 'name';
				}
				else
				{
					// We have no other choice but to just get the first element's key.
					$key = key($row);
				}
			}

			$this->dataCache['field_names'][$table][] = $row[$key];
		}

		return $this->dataCache['field_names'][$table];
	}
Fetch Field Names

@param string $table Table name

@return array|false
@throws DatabaseException