system/Database/BaseConnection.php
public function escapeIdentifiers($item)
	{
		if ($this->escapeChar === '' || empty($item) || in_array($item, $this->reservedIdentifiers))
		{
			return $item;
		}
		elseif (is_array($item))
		{
			foreach ($item as $key => $value)
			{
				$item[$key] = $this->escapeIdentifiers($value);
			}

			return $item;
		}
		// Avoid breaking functions and literal values inside queries
		elseif (ctype_digit($item) || $item[0] === "'" || ( $this->escapeChar !== '"' && $item[0] === '"') ||
				strpos($item, '(') !== false
		)
		{
			return $item;
		}

		static $preg_ec = [];

		if (empty($preg_ec))
		{
			if (is_array($this->escapeChar))
			{
				$preg_ec = [
					preg_quote($this->escapeChar[0], '/'),
					preg_quote($this->escapeChar[1], '/'),
					$this->escapeChar[0],
					$this->escapeChar[1],
				];
			}
			else
			{
				$preg_ec[0] = $preg_ec[1] = preg_quote($this->escapeChar, '/');
				$preg_ec[2] = $preg_ec[3] = $this->escapeChar;
			}
		}

		foreach ($this->reservedIdentifiers as $id)
		{
			if (strpos($item, '.' . $id) !== false)
			{
				return preg_replace('/' . $preg_ec[0] . '?([^' . $preg_ec[1] . '\.]+)' . $preg_ec[1] . '?\./i', $preg_ec[2] . '$1' . $preg_ec[3] . '.', $item);
			}
		}

		return preg_replace('/' . $preg_ec[0] . '?([^' . $preg_ec[1] . '\.]+)' . $preg_ec[1] . '?(\.)?/i', $preg_ec[2] . '$1' . $preg_ec[3] . '$2', $item);
	}
public function escapeIdentifiers($item)
	{
		if ($this->escapeChar === '' || empty($item) || in_array($item, $this->reservedIdentifiers))
		{
			return $item;
		}
		elseif (is_array($item))
		{
			foreach ($item as $key => $value)
			{
				$item[$key] = $this->escapeIdentifiers($value);
			}

			return $item;
		}
		// Avoid breaking functions and literal values inside queries
		elseif (ctype_digit($item) || $item[0] === "'" || ( $this->escapeChar !== '"' && $item[0] === '"') ||
				strpos($item, '(') !== false
		)
		{
			return $item;
		}

		static $preg_ec = [];

		if (empty($preg_ec))
		{
			if (is_array($this->escapeChar))
			{
				$preg_ec = [
					preg_quote($this->escapeChar[0], '/'),
					preg_quote($this->escapeChar[1], '/'),
					$this->escapeChar[0],
					$this->escapeChar[1],
				];
			}
			else
			{
				$preg_ec[0] = $preg_ec[1] = preg_quote($this->escapeChar, '/');
				$preg_ec[2] = $preg_ec[3] = $this->escapeChar;
			}
		}

		foreach ($this->reservedIdentifiers as $id)
		{
			if (strpos($item, '.' . $id) !== false)
			{
				return preg_replace('/' . $preg_ec[0] . '?([^' . $preg_ec[1] . '\.]+)' . $preg_ec[1] . '?\./i', $preg_ec[2] . '$1' . $preg_ec[3] . '.', $item);
			}
		}

		return preg_replace('/' . $preg_ec[0] . '?([^' . $preg_ec[1] . '\.]+)' . $preg_ec[1] . '?(\.)?/i', $preg_ec[2] . '$1' . $preg_ec[3] . '$2', $item);
	}
Escape the SQL Identifiers

This function escapes column and table names

@param mixed $item

@return mixed