Package org.apache.calcite.adapter.druid

Class DruidExpressions

java.lang.Object

org.apache.calcite.adapter.druid.DruidExpressions

public class DruidExpressions
extends Object

Expression utility class to transform Calcite expressions to Druid expressions when possible.

Method Summary

Modifier and Type	Method	Description
static String	applyTimeExtract(String timeExpression, String druidUnit, TimeZone timeZone)
static String	applyTimestampCeil(String input, String granularity, String origin, TimeZone timeZone)
static String	applyTimestampFloor(String input, String granularity, String origin, TimeZone timeZone)
static String	fromColumn(String columnName)
static String	functionCall(String functionName, List<String> args)
static String	nAryOperatorCall(String druidOperator, List<String> args)
static String	nullLiteral()
static String	numberLiteral(Number n)
static String	stringLiteral(String s)
static @Nullable String	toDruidExpression(RexNode rexNode, RelDataType inputRowType, DruidQuery druidRel)	Translates a Calcite RexNode to a Druid expression, if possible; returns null if not possible.
static @Nullable List<String>	toDruidExpressions(DruidQuery druidRel, RelDataType rowType, List<RexNode> rexNodes)	Translate a list of Calcite RexNode to Druid expressions.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

toDruidExpression

public static @Nullable String toDruidExpression(RexNode rexNode,
 RelDataType inputRowType,
 DruidQuery druidRel)

Translates a Calcite RexNode to a Druid expression, if possible; returns null if not possible.

Parameters:

rexNode - RexNode to convert to a Druid Expression

inputRowType - Input row type of the rexNode to translate

druidRel - Druid query

Returns:

Druid Expression, or null when can not convert the RexNode

fromColumn

public static String fromColumn(String columnName)

nullLiteral

public static String nullLiteral()

numberLiteral

public static String numberLiteral(Number n)

stringLiteral

public static String stringLiteral(String s)

functionCall

public static String functionCall(String functionName,
 List<String> args)

nAryOperatorCall

public static String nAryOperatorCall(String druidOperator,
 List<String> args)

toDruidExpressions

public static @Nullable List<String> toDruidExpressions(DruidQuery druidRel,
 RelDataType rowType,
 List<RexNode> rexNodes)

Translate a list of Calcite RexNode to Druid expressions.

Parameters:

rexNodes - list of Calcite expressions meant to be applied on top of the rows

Returns:

list of Druid expressions in the same order as rexNodes, or null if not possible. If a non-null list is returned, all elements will be non-null.

applyTimestampFloor

public static String applyTimestampFloor(String input,
 String granularity,
 String origin,
 TimeZone timeZone)

applyTimestampCeil

public static String applyTimestampCeil(String input,
 String granularity,
 String origin,
 TimeZone timeZone)

applyTimeExtract

public static String applyTimeExtract(String timeExpression,
 String druidUnit,
 TimeZone timeZone)