Package tech.tablesaw.columns.strings

Class StringColumnReference

java.lang.Object

tech.tablesaw.columns.ColumnReference

tech.tablesaw.columns.strings.StringColumnReference

public class StringColumnReference
extends ColumnReference

A reference to a column that can be used in evaluating query predicates. It is a key part of having a fluent API for querying tables.

Basically, it lets you write a query like this:

table.select(column("foo").isEqualTo("Bar"));

In that example, column() is a static method that returns a ColumnReference for a column named "foo". The method isEqualTo(), is implemented on ColumnReference in a way that it can be applied to potentially, multiple column types, although in this case, it only makes sense for CategoryColumns since the argument is a string.

When select() isExecuted, it supplies the table to the ColumnReference. The ColumnReference uses the table and columnName to get access to the right column, and then fulfils its role by ensuring that the filtering "isEqualTo("Bar") is applied to all the cells in the column.

Constructor Summary

Constructors

Constructor	Description
StringColumnReference(String column)

Method Summary

Modifier and Type	Method	Description
Filter	containsString(String string)
Filter	containsString(StringColumn sc)
Filter	endsWith(String string)
Filter	endsWith(StringColumn sc)
Filter	endsWith(StringColumnReference ref)
Filter	equalsIgnoreCase(String string)
Filter	equalsIgnoreCase(StringColumn stringColumnToCompareAgainst)
Filter	equalsIgnoreCase(StringColumnReference stringColumnToCompareAgainst)
Filter	isAlpha()
Filter	isAlphaNumeric()
Filter	isEmptyString()
Filter	isEqualTo(String value)
Filter	isEqualTo(StringColumn value)
Filter	isEqualTo(StringColumnReference value)
Filter	isIn(String... strings)
Filter	isIn(List<String> strings)
Filter	isLongerThan(int length)
Filter	isLowerCase()
Filter	isNotEqualTo(String value)
Filter	isNotEqualTo(StringColumn value)
Filter	isNotEqualTo(StringColumnReference value)
Filter	isNotIn(String... strings)
Filter	isNotIn(List<String> strings)
Filter	isNumeric()
Filter	isShorterThan(int length)
Filter	isUpperCase()
Filter	lengthEquals(int length)
Filter	matchesRegex(String string)
Filter	startsWith(String string)
Filter	startsWith(StringColumn sc)
Filter	startsWith(StringColumnReference ref)

Methods inherited from class tech.tablesaw.columns.ColumnReference

getColumnName, isMissing, isNotMissing

Methods inherited from class java.lang.Object

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

Constructor Detail

StringColumnReference

public StringColumnReference(String column)

Method Detail

isEqualTo

public Filter isEqualTo(String value)

isNotEqualTo

public Filter isNotEqualTo(String value)

isIn

public Filter isIn(String... strings)

isNotIn

public Filter isNotIn(String... strings)

isIn

public Filter isIn(List<String> strings)

isNotIn

public Filter isNotIn(List<String> strings)

isUpperCase

public Filter isUpperCase()

isLowerCase

public Filter isLowerCase()

isAlpha

public Filter isAlpha()

isAlphaNumeric

public Filter isAlphaNumeric()

isNumeric

public Filter isNumeric()

isEmptyString

public Filter isEmptyString()

isLongerThan

public Filter isLongerThan(int length)

isShorterThan

public Filter isShorterThan(int length)

lengthEquals

public Filter lengthEquals(int length)

equalsIgnoreCase

public Filter equalsIgnoreCase(String string)

startsWith

public Filter startsWith(String string)

endsWith

public Filter endsWith(String string)

containsString

public Filter containsString(String string)

containsString

public Filter containsString(StringColumn sc)

matchesRegex

public Filter matchesRegex(String string)

startsWith

public Filter startsWith(StringColumn sc)

startsWith

public Filter startsWith(StringColumnReference ref)

endsWith

public Filter endsWith(StringColumn sc)

endsWith

public Filter endsWith(StringColumnReference ref)

isEqualTo

public Filter isEqualTo(StringColumn value)

isEqualTo

public Filter isEqualTo(StringColumnReference value)

isNotEqualTo

public Filter isNotEqualTo(StringColumn value)

isNotEqualTo

public Filter isNotEqualTo(StringColumnReference value)

equalsIgnoreCase

public Filter equalsIgnoreCase(StringColumn stringColumnToCompareAgainst)

equalsIgnoreCase

public Filter equalsIgnoreCase(StringColumnReference stringColumnToCompareAgainst)