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.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static Map<SqlTypeName,DruidType>	EXPRESSION_TYPES Type mapping between Calcite SQL family types and native Druid expression types
private static char[]	SAFE_CHARS Druid expression safe chars, must be sorted.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	DruidExpressions()

Method Summary

Modifier and Type	Method and 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)
private static String	escape(String s)
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 String	toDruidExpression(RexNode rexNode, RelDataType inputRowType, DruidQuery druidRel) Translates Calcite rexNode to Druid Expression when possible
static 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

Field Detail

EXPRESSION_TYPES

static final Map<SqlTypeName,DruidType> EXPRESSION_TYPES

Type mapping between Calcite SQL family types and native Druid expression types

SAFE_CHARS

private static final char[] SAFE_CHARS

Druid expression safe chars, must be sorted.

Constructor Detail

DruidExpressions

private DruidExpressions()

Method Detail

toDruidExpression

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

Translates Calcite rexNode to Druid Expression when 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)

escape

private static String escape(String s)

functionCall

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

nAryOperatorCall

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

toDruidExpressions

@Nullable
public static 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)