framework/db/Schema.php
public function unquoteSimpleColumnName($name)
    {
        if (is_string($this->columnQuoteCharacter)) {
            $startingCharacter = $this->columnQuoteCharacter;
        } else {
            $startingCharacter = $this->columnQuoteCharacter[0];
        }
        return strpos($name, $startingCharacter) === false ? $name : substr($name, 1, -1);
    }
public function unquoteSimpleColumnName($name)
    {
        if (is_string($this->columnQuoteCharacter)) {
            $startingCharacter = $this->columnQuoteCharacter;
        } else {
            $startingCharacter = $this->columnQuoteCharacter[0];
        }
        return strpos($name, $startingCharacter) === false ? $name : substr($name, 1, -1);
    }
Unquotes a simple column name.
A simple column name should contain the column name only without any prefix.
If the column name is not quoted or is the asterisk character '*', this method will do nothing.
@param string $name column name.
@return string unquoted column name.
@since 2.0.14