Escape single quote in xslt concat function
In XPath 1.0:
You can use the built-in entities ' and "
In XSLT 1.0:
Alternatively, you can define your $Q and $APOS variables (put the content (the literal " or the literal ' character) in the body of the xsl:variable, not in the select attribute).
In XPath 2.x (this also means XSLT 2.x and XQuery 1.x)
Simply escape an apostrophe by entering two adjacent apostrophes, escape a quote by entering two adjacent quotes, as defined by the XPath 2.0 language
To expand on Dimitre's answer, you can use this solution in XSLT:
<xsl:variable name="apos">'</xsl:variable><xsl:value-of select="concat('process[@Ref=',$apos,$ID,$apos,']')"></xsl:value-of>
Use '?
<xsl:value-of select="concat('process[@Ref='',$ID,'']')"></xsl:value-of>Edit: See Dimitre's answer for a better solution.