com.yahoo.bard.webservice.sql.helper

Class SqlTimeConverter

java.lang.Object

com.yahoo.bard.webservice.sql.helper.SqlTimeConverter

public class SqlTimeConverter
extends Object

Handles converting between a DefaultTimeGrain and a list of SqlDatePartFunction to create groupBy statements on intervals of time.

Constructor Summary

Constructors

Constructor and Description
SqlTimeConverter() Builds a sql time converter which can group by, filter, and reparse dateTimes from a row in a ResultSet using the buildDefaultGranularityToDateFunctionsMap() map.
SqlTimeConverter(Map<Granularity,List<org.apache.calcite.sql.fun.SqlDatePartFunction>> granularityToDateFunctionMap) Builds a sql time converter which can group by, filter, and reparse dateTimes from a row in a ResultSet.

Method Summary

Modifier and Type	Method and Description
static Map<Granularity,List<org.apache.calcite.sql.fun.SqlDatePartFunction>>	buildDefaultGranularityToDateFunctionsMap() Builds the default mapping between Granularity and the SqlDatePartFunctions needed to group on and read into a DateTime.
List<org.apache.calcite.rex.RexNode>	buildGroupBy(org.apache.calcite.tools.RelBuilder builder, Granularity granularity, String timeColumn) Builds a list of RexNode which will effectively groupBy the given Granularity.
org.apache.calcite.rex.RexNode	buildTimeFilters(org.apache.calcite.tools.RelBuilder builder, DruidAggregationQuery<?> druidQuery, String timestampColumn) Builds the time filters to only select rows that occur within the intervals of the query.
org.joda.time.DateTime	getIntervalStart(int offset, String[] recordValues, DruidAggregationQuery<?> druidQuery) Given an array of strings (a row from a ResultSet) and the Granularity used to make groupBy statements on time, it will parse out a DateTime for the row which represents the beginning of the interval it was grouped on.
protected void	setDateTime(int value, org.apache.calcite.sql.fun.SqlDatePartFunction sqlDatePartFn, org.joda.time.MutableDateTime dateTime) Sets the correct part of a DateTime corresponding to a SqlDatePartFunction.
List<org.apache.calcite.sql.fun.SqlDatePartFunction>	timeGrainToDatePartFunctions(Granularity granularity) Gets a list of SqlDatePartFunction to be performed on a timestamp which can be used to group by the given Granularity.

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlTimeConverter

public SqlTimeConverter()

Builds a sql time converter which can group by, filter, and reparse dateTimes from a row in a ResultSet using the buildDefaultGranularityToDateFunctionsMap() map.

SqlTimeConverter

public SqlTimeConverter(Map<Granularity,List<org.apache.calcite.sql.fun.SqlDatePartFunction>> granularityToDateFunctionMap)

Builds a sql time converter which can group by, filter, and reparse dateTimes from a row in a ResultSet.

Parameters:

granularityToDateFunctionMap - The mapping defining what granularity needs to be kept in order to properly group by and reparse a dateTime.

Method Detail

buildDefaultGranularityToDateFunctionsMap

public static Map<Granularity,List<org.apache.calcite.sql.fun.SqlDatePartFunction>> buildDefaultGranularityToDateFunctionsMap()

Builds the default mapping between Granularity and the SqlDatePartFunctions needed to group on and read into a DateTime.

Returns:

the mapping between Granularity and SqlDatePartFunctions.

timeGrainToDatePartFunctions

public List<org.apache.calcite.sql.fun.SqlDatePartFunction> timeGrainToDatePartFunctions(Granularity granularity)

Gets a list of SqlDatePartFunction to be performed on a timestamp which can be used to group by the given Granularity.

Parameters:

granularity - The granularity to map to a list of SqlDatePartFunction.

Returns:

the list of sql functions.

buildTimeFilters

public org.apache.calcite.rex.RexNode buildTimeFilters(org.apache.calcite.tools.RelBuilder builder,
                                                       DruidAggregationQuery<?> druidQuery,
                                                       String timestampColumn)

Builds the time filters to only select rows that occur within the intervals of the query. NOTE: you must have one interval to select on.

Parameters:

builder - The RelBuilder used for building queries.

druidQuery - The druid query to build filters over.

timestampColumn - The name of the timestamp column in the database.

Returns:

the RexNode for filtering to only the given intervals.

buildGroupBy

public List<org.apache.calcite.rex.RexNode> buildGroupBy(org.apache.calcite.tools.RelBuilder builder,
                                                         Granularity granularity,
                                                         String timeColumn)

Builds a list of RexNode which will effectively groupBy the given Granularity.

Parameters:

builder - The RelBuilder used with calcite to build queries.

granularity - The granularity to build the groupBy for.

timeColumn - The name of the timestamp column.

Returns:

the list of RexNode needed in the groupBy.

getIntervalStart

public org.joda.time.DateTime getIntervalStart(int offset,
                                               String[] recordValues,
                                               DruidAggregationQuery<?> druidQuery)

Given an array of strings (a row from a ResultSet) and the Granularity used to make groupBy statements on time, it will parse out a DateTime for the row which represents the beginning of the interval it was grouped on.

Parameters:

offset - the last column before the date fields.

recordValues - The results returned by Sql needed to read the time columns.

druidQuery - The original druid query which was made using calling buildGroupBy(RelBuilder, Granularity, String).

Returns:

the datetime for the start of the interval.

setDateTime

protected void setDateTime(int value,
                           org.apache.calcite.sql.fun.SqlDatePartFunction sqlDatePartFn,
                           org.joda.time.MutableDateTime dateTime)

Sets the correct part of a DateTime corresponding to a SqlDatePartFunction.

Parameters:

value - The value to be set for the dateTime with the sqlDatePartFn

sqlDatePartFn - The function used to extract part of a date with sql.

dateTime - The original dateTime to create a copy of.