Package com.apple.foundationdb.record.query.expressions

Class Field

java.lang.Object

com.apple.foundationdb.record.query.expressions.Field

@API(MAINTAINED)
public class Field
extends Object

Class that provides context for asserting about a field value. oneOfThem() and matches(QueryComponent) allow you to create other components, while the remaining functions allow you to match on the value of the associated field directly.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Field.OneOfThemEmptyMode	How an empty / unset repeated field should be handled.

Constructor Summary

Constructors

Constructor	Description
Field(String fieldName)

Method Summary

Modifier and Type	Method	Description
QueryComponent	equalsParameter(String param)	Checks if the field has a value equal to the given parameter.
QueryComponent	equalsValue(Object comparand)	Checks if the field has a value equal to the given comparand.
QueryComponent	greaterThan(Object comparand)	Checks if the field has a value greater than the given comparand.
QueryComponent	greaterThanOrEquals(Object comparand)	Checks if the field has a value greater than or equal to the given comparand.
QueryComponent	in(String param)	Query where the value of this field is in the list that is bound to the given param.
QueryComponent	in(List<?> comparand)	Query where the value of this field is in the given list.
QueryComponent	isEmpty()	Returns true if the repeated field does not have any occurrences.
QueryComponent	isNull()	Returns true if the field has not been set and uses the default value.
QueryComponent	lessThan(Object comparand)	Checks if the field has a value less than the given comparand.
QueryComponent	lessThanOrEquals(Object comparand)	Checks if the field has a value less than or equal to the given comparand.
QueryComponent	mapMatches(Function<Field,QueryComponent> keyMatcher, Function<Field,QueryComponent> valueMatcher)	Match map field entries.
QueryComponent	matches(QueryComponent child)	If the associated field is a submessage, this allows you to match against the fields within that submessage.
QueryComponent	notEmpty()	Returns true if the repeated field has occurrences.
QueryComponent	notEquals(Object comparand)	Checks if the field has a value not equal to the given comparand.
QueryComponent	notNull()	Returns true if the field does not use the default value.
OneOfThem	oneOfThem()	If the associated field is a repeated one, this allows you to match against one of the repeated values.
OneOfThem	oneOfThem(Field.OneOfThemEmptyMode emptyMode)	If the associated field is a repeated one, this allows you to match against one of the repeated values.
QueryComponent	startsWith(String comparand)	Checks if the field starts with the given string.
Text	text()	Query where the value of this field matches some property when performing a full-text search.
Text	text(String tokenizerName)	Query where the value of this field matches some property when performing a full-text search.
Text	text(String tokenizerName, String defaultTokenizerName)	Query where the value of this field matches some property when performing a full-text search.

Methods inherited from class java.lang.Object

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

Constructor Detail

Field

public Field(@Nonnull
             String fieldName)

Method Detail

matches

@Nonnull
public QueryComponent matches(@Nonnull
                              QueryComponent child)

If the associated field is a submessage, this allows you to match against the fields within that submessage. The child is evaluated and validated in the context of this field, not the record containing this field.

Parameters:

child - a component asserting about the content of the submessage in this field

Returns:

a new component ready for evaluation

oneOfThem

@Nonnull
public OneOfThem oneOfThem()

If the associated field is a repeated one, this allows you to match against one of the repeated values. The record will be returned if any one of the values returns true. The same record may be returned more than once. If the repeated field is empty, the match result will be UNKNOWN.

Returns:

an OneOfThem that can have further assertions called on it about the value of the given field

oneOfThem

@Nonnull
public OneOfThem oneOfThem(Field.OneOfThemEmptyMode emptyMode)

If the associated field is a repeated one, this allows you to match against one of the repeated values. The record will be returned if any one of the values returns true. The same record may be returned more than once.

Parameters:

emptyMode - whether an empty repeated field should cause an UNKNOWN result instead of failing to match any (and so returning FALSE)

Returns:

an OneOfThem that can have further assertions called on it about the value of the given field

equalsValue

@Nonnull
public QueryComponent equalsValue(@Nonnull
                                  Object comparand)

Checks if the field has a value equal to the given comparand. Evaluates to null if the field does not have a value.

Parameters:

comparand - the object to compare with the value in the field

Returns:

a new component for doing the actual evaluation

notEquals

@Nonnull
public QueryComponent notEquals(@Nonnull
                                Object comparand)

Checks if the field has a value not equal to the given comparand. Evaluates to null if the field does not have a value.

Parameters:

comparand - the object to compare with the value in the field

Returns:

a new component for doing the actual evaluation

greaterThan

@Nonnull
public QueryComponent greaterThan(@Nonnull
                                  Object comparand)

Checks if the field has a value greater than the given comparand. Evaluates to null if the field does not have a value.

Parameters:

comparand - the object to compare with the value in the field

Returns:

a new component for doing the actual evaluation

greaterThanOrEquals

@Nonnull
public QueryComponent greaterThanOrEquals(@Nonnull
                                          Object comparand)

Checks if the field has a value greater than or equal to the given comparand. Evaluates to null if the field does not have a value.

Parameters:

comparand - the object to compare with the value in the field

Returns:

a new component for doing the actual evaluation

lessThan

@Nonnull
public QueryComponent lessThan(@Nonnull
                               Object comparand)

Checks if the field has a value less than the given comparand. Evaluates to null if the field does not have a value.

Parameters:

comparand - the object to compare with the value in the field

Returns:

a new component for doing the actual evaluation

lessThanOrEquals

@Nonnull
public QueryComponent lessThanOrEquals(@Nonnull
                                       Object comparand)

Checks if the field has a value less than or equal to the given comparand. Evaluates to null if the field does not have a value.

Parameters:

comparand - the object to compare with the value in the field

Returns:

a new component for doing the actual evaluation

startsWith

@Nonnull
public QueryComponent startsWith(@Nonnull
                                 String comparand)

Checks if the field starts with the given string. Requires that the field contains a string. Evaluates to null if the field does not have a value.

Parameters:

comparand - the object to compare with the value in the field

Returns:

a new component for doing the actual evaluation

isNull

@Nonnull
public QueryComponent isNull()

Returns true if the field has not been set and uses the default value.

Returns:

a new component for doing the actual evaluation

notNull

@Nonnull
public QueryComponent notNull()

Returns true if the field does not use the default value.

Returns:

a new component for doing the actual evaluation

isEmpty

@Nonnull
public QueryComponent isEmpty()

Returns true if the repeated field does not have any occurrences.

Returns:

a new component for doing the actual evaluation

notEmpty

@Nonnull
public QueryComponent notEmpty()

Returns true if the repeated field has occurrences.

Returns:

a new component for doing the actual evaluation

in

@Nonnull
public QueryComponent in(@Nonnull
                         List<?> comparand)

Query where the value of this field is in the given list.

Parameters:

comparand - a list of elements

Returns:

a new component for doing the actual evaluation

in

@Nonnull
public QueryComponent in(@Nonnull
                         String param)

Query where the value of this field is in the list that is bound to the given param.

Parameters:

param - a param that will be bound to a list in the execution context

Returns:

a new component for doing the actual evaluation

text

@Nonnull
public Text text()

Query where the value of this field matches some property when performing a full-text search. It does not specify any tokenizer information, so it is assumed that any tokenizer is acceptable for parsing query string (if not already tokenized) or to parse the record's text or to match against an index. If an index is used during query execution, then it is guaranteed that the same tokenizer that was used to tokenize the index is used to tokenize the query string (if not already tokenized).

Returns:

an intermediate object to use to select the appropriate predicate

text

@Nonnull
public Text text(@Nullable
                 String tokenizerName)

Query where the value of this field matches some property when performing a full-text search. If tokenizerName is not null, then this will use that tokenizer to tokenize the query string (if not already tokenized) and to parse the record's text. If an index is used, then it is guaranteed that the index uses this same tokenizer. If tokenizerName is null, then this behaves the same as text().

Parameters:

tokenizerName - the name of the tokenizer to use to tokenize the record and (if necessary) the query string

Returns:

an intermediate object to use to select the appropriate predicate

text

@Nonnull
public Text text(@Nullable
                 String tokenizerName,
                 @Nullable
                 String defaultTokenizerName)

Query where the value of this field matches some property when performing a full-text search. If tokenizerName is not null, then this will use that tokenizer to tokenize the query string (if not already tokenized) and to parse the record's text. If an index is used, then it is guaranteed that the index uses this same tokenizer. If tokenizerName is null, then this behaves the same as text() except that if defaultTokenizerName is not null, then it will use that tokenizer to tokenize the document and query string (if no index is available) instead of the normal default tokenizer, DefaultTextTokenizer.

Parameters:

tokenizerName - the name of the tokenizer to use to tokenize the record and (if necessary) the query string

defaultTokenizerName - the name of the tokenizer to use if tokenizerName is null and no index can be found to satisfy the query

Returns:

an intermediate object to use to select the appropriate predicate

equalsParameter

@Nonnull
public QueryComponent equalsParameter(@Nonnull
                                      String param)

Checks if the field has a value equal to the given parameter. Evaluates to null if the field does not have a value.

Parameters:

param - the name of the parameter

Returns:

a new component for doing the actual evaluation

mapMatches

@Nonnull
public QueryComponent mapMatches(@Nullable
                                 Function<Field,QueryComponent> keyMatcher,
                                 @Nullable
                                 Function<Field,QueryComponent> valueMatcher)

Match map field entries.

 Query.field("map_field").mapMatches(k -> k.equals("akey"), v -> v.greaterThan(10))
 

Parameters:

keyMatcher - a function to apply to the key Field or null not to restrict the key

valueMatcher - a function to apply to the value Field or null not to restrict the value

Returns:

a new component that will return the record if the map field has an entry matching the key and value criteria