Package tech.tablesaw.api

Class QueryHelper

java.lang.Object

tech.tablesaw.api.QueryHelper

public class QueryHelper
extends Object

A static utility class designed to take some of the work, and verbosity, out of making queries.

It is intended to be imported statically in any class that will run queries as it makes them easier to write - and read.

Constructor Summary

Constructors

Constructor	Description
QueryHelper()

Method Summary

Modifier and Type	Method	Description
static Filter	allOf(Filter... filters)
static Filter	and(Filter... filters)
static Filter	anyOf(Filter... filters)
static BooleanColumnReference	booleanColumn(String columnName)
static Filter	both(Filter a, Filter b)
static DateColumnReference	dateColumn(String columnName)
static DateTimeColumnReference	dateTimeColumn(String columnName)
static Filter	either(Filter a, Filter b)
static Filter	not(Filter filter)
static NumberColumnReference	numberColumn(String columnName)
static Filter	or(Filter... filters)
static StringColumnReference	stringColumn(String columnName)	Returns a column reference for a String column with the given name.
static TimeColumnReference	timeColumn(String columnName)

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryHelper

public QueryHelper()

Method Detail

stringColumn

public static StringColumnReference stringColumn(String columnName)

Returns a column reference for a String column with the given name. It will be resolved at query time by associating it with a table. At construction time, the columnType is unknown, so the user has to pick the correct type.

timeColumn

public static TimeColumnReference timeColumn(String columnName)

dateColumn

public static DateColumnReference dateColumn(String columnName)

dateTimeColumn

public static DateTimeColumnReference dateTimeColumn(String columnName)

numberColumn

public static NumberColumnReference numberColumn(String columnName)

booleanColumn

public static BooleanColumnReference booleanColumn(String columnName)

both

public static Filter both(Filter a,
                          Filter b)

allOf

public static Filter allOf(Filter... filters)

and

public static Filter and(Filter... filters)

not

public static Filter not(Filter filter)

either

public static Filter either(Filter a,
                            Filter b)

anyOf

public static Filter anyOf(Filter... filters)

or

public static Filter or(Filter... filters)