Data-Driven dynamic forms in Apache Zeppelin

cell1.scala

def list(table: String, col: String) : Array[(String, String)] = {
  sqlContext.sql("select distinct " + col + " from " + table + " order by " + col).collect.map(x => (x(0).asInstanceOf[String], x(0).asInstanceOf[String]))
}

def tables(): Array[(String, String)] = {
 sqlContext.sql("show tables").collect.map(x => (x(0).asInstanceOf[String], x(0).asInstanceOf[String]))
}

def columns(table: String) : Array[(String, String)] = {
  sqlContext.sql("select * from " + table + " limit 0").columns.map(x => (x, x))
}

val table = z.select("table", tables()).asInstanceOf[String]
val col1 = z.select("col1", columns(table))
val col2 = z.select("col2", columns(table))
val query = "select " + col1 + "," + col2 + ", count(*) as count from " + table + " group by " + col1 + "," + col2 + " order by count desc"
val df = sqlContext.sql(query)
println("%table " + df.columns.mkString("\t"))
println(df.map(x => x.mkString("\t")).collect().mkString("\n"))