Support Date_Format in JS

src/main/scala/org/sparklinedata/druid/jscodegen/JSCodeGenerator.scala

@@ -305,6 +305,13 @@ case class JSCodeGenerator(dqb: DruidQueryBuilder, e: Expression, mulInParamsAll
         case TruncDate(d, f@Literal(v, _)) if v.isInstanceOf[UTF8String] =>
           for (de <- genExprCode(d); tr <- trunc(de.getRef, f.value.toString)) yield
             JSExpr(None, de.linesSoFar, tr, DateType)
+        case DateFormatClass(de, fmt) => {
+          for (jsDe <- genExprCode(de);
+               jsFmt <- genExprCode(fmt);
+               fmtDStr <- dateFormatCode(jsDe, jsFmt.curLine)) yield {
+            JSExpr(None, jsDe.linesSoFar + jsFmt.linesSoFar, fmtDStr, StringType, false)
+          }
+        }
         case Add(l, r) => Some(genBArithmeticExprCode(l, r, e, "+")).flatten
         case Subtract(l, r) => Some(genBArithmeticExprCode(l, r, e, "-")).flatten
         case Multiply(l, r) => Some(genBArithmeticExprCode(l, r, e, "*")).flatten

src/main/scala/org/sparklinedata/druid/jscodegen/JSDateTime.scala

@@ -17,6 +17,8 @@
 
 package org.sparklinedata.druid.jscodegen
 
+import org.apache.spark.sql.types.{DateType, StringType, TimestampType}
+
 
 private[jscodegen] case class JSDateTimeCtx(val tz_id: String, val ctx: JSCodeGenerator) {
   private[jscodegen] val tzVar: String = ctx.makeUniqueVarName
@@ -51,6 +53,16 @@ private[jscodegen] object JSDateTimeCtx {
   private val timeStampFormat = "yyyy-MM-dd HH:mm:ss"
   private val mSecsInDay = 86400000
 
+  private[jscodegen] def dateFormatCode(dtVal: JSExpr, fmt: String): Option[String] =
+    for (javaDate <- dtVal.fnDT match {
+      case TimestampType => Some(s"""${dtVal.curLine}.toDate()""".stripMargin)
+      case DateType => Some(s"""${dtVal.curLine}.toDate()""".stripMargin)
+      case StringType => Some(s"""${dtVal.curLine}""".stripMargin)
+      case _ => None
+    }) yield {
+      s"(new java.text.SimpleDateFormat(${fmt})).format(${javaDate})"
+    }
+
   private[jscodegen] def dtInFormatCode(f: String, ctx: JSDateTimeCtx) = {
     ctx.createJodaTZ = true
     s"""org.joda.time.format.forPattern($f).withZone(${ctx.tzVar})""".stripMargin

src/test/scala/org/sparklinedata/druid/client/CodeGenTest.scala

@@ -799,5 +799,23 @@ class CodeGenTest extends BaseTest with BeforeAndAfterAll with Logging {
       |order by x, y
     """.stripMargin
     ,0,true,true)
+
+  test("date_format1",
+    """
+      |select o_orderstatus as x, date_format(cast(o_orderdate as date), 'YY') as y
+      |from orderLineItemPartSupplier
+      |group by o_orderstatus, date_format(cast(o_orderdate as date), 'YY')
+      |order by x, y
+    """.stripMargin
+    ,1,true,true)
+
+  test("date_format2",
+    """
+      |select o_orderstatus as x, date_format(cast(o_orderdate as date), 'u') as y
+      |from orderLineItemPartSupplier
+      |group by o_orderstatus, date_format(cast(o_orderdate as date), 'u')
+      |order by x, y
+    """.stripMargin
+    ,1,true,true)
 }