https://community.cloudera.com/t5/Support-Questions/Read-a-flowfile-with-groovy-error/m-p/233767#M195590 <P>Thank you for your response. Actually it's my post.</P><P>I used SQL.mydb.execute(createTable.toString()) but I got the same error which due to this instruction </P><PRE>def schema = ff.read().withReader("UTF-8"){newJsonSlurper().parse(it). </PRE><P>So I changed the code</P><PRE>import groovy.json.JsonSlurper import org.apache.commons.io.IOUtils import java.nio.charset.StandardCharsets def ff = session.get() if(!ff)return def schema = '' session.read(ff, {inputStream -&gt; schema= IOUtils.toString(inputStream, StandardCharsets.UTF_8) } as InputStreamCallback) //define type mapping def typeMap = [ "string" : "varchar(255)", "long" : "numeric(10)", [ "null", "string" ]: "varchar(255)", [ "null", "long" ] : "numeric(10)", ] //build create table statement def createTable = "create table ${schema.name} (" + schema.fields.collect{ "\n ${it.name.padRight(39)} ${typeMap[it.type]}" }.join(',') + "\n)" //execute statement through the custom defined property //SQL.mydb references <A href="http://docs.groovy-lang.org/2.4.10/html/api/groovy/sql/Sql.html" target="_blank">http://docs.groovy-lang.org/2.4.10/html/api/groovy/sql/Sql.html</A> object SQL.mydb.execute(createTable.toString()) //transfer flow file to success REL_SUCCESS &lt;&lt; ff</PRE><PRE>error : groovy.lang.missingpropertyexception no such property for class java.lang.string</PRE> Tue, 06 Mar 2018 00:26:49 GMT AmiraKhalifa 2018-03-06T00:26:49Z