Selector (DataStax Java driver for Apache Cassandra(R) 4.17.0 API)

All Superinterfaces:

CqlSnippet

All Known Subinterfaces:

Literal, Raw
```
public interface Selector
extends CqlSnippet
```
A selected element in a SELECT query.
To build instances of this type, use the factory methods, such as column, function, etc.
They are used as arguments to the selectors method, for example:
```
 selectFrom("foo").selectors(Selector.column("bar"), Selector.column("baz"))
 // SELECT bar,baz FROM foo
 
```
There are also shortcuts in the fluent API when you build a statement, for example:
```
 selectFrom("foo").column("bar").column("baz")
 // SELECT bar,baz FROM foo
 
```

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`static Selector`	`add(Selector left, Selector right)` Selects the sum of two arguments, as in `SELECT col1 + col2`.
`static Selector`	`all()` Selects all columns, as in `SELECT *`.
`Selector`	`as(CqlIdentifier alias)` Aliases the selector, as in `SELECT count(*) AS total`.
`default Selector`	`as(String alias)` Shortcut for `as(CqlIdentifier.fromCql(alias))`
`static Selector`	`cast(Selector selector, DataType targetType)` Casts a selector to a type, as in `SELECT CAST(a AS double)`.
`static Selector`	`column(CqlIdentifier columnId)` Selects a particular column by its CQL identifier.
`static Selector`	`column(String columnName)` Shortcut for `column(CqlIdentifier.fromCql(columnName))`
`static Selector`	`countAll()` Selects the count of all returned rows, as in `SELECT count(*)`.
`static Selector`	`divide(Selector left, Selector right)` Selects the quotient of two arguments, as in `SELECT col1 / col2`.
`static Selector`	`element(CqlIdentifier collectionId, Term index)` Shortcut for element selection when the target collection is a simple column.
`static Selector`	`element(Selector collection, Term index)` Selects an element in a collection column, as in `SELECT m['key']`.
`static Selector`	`element(String collectionName, Term index)` Shortcut for `element(CqlIdentifier.fromCql(collectionName), index)`.
`static Selector`	`field(CqlIdentifier udtColumnId, CqlIdentifier fieldId)` Shortcut to select a UDT field when the UDT is a simple column (as opposed to a more complex selection, like a nested UDT).
`static Selector`	`field(Selector udt, CqlIdentifier fieldId)` Selects a field inside of a UDT column, as in `SELECT user.name`.
`static Selector`	`field(Selector udt, String fieldName)` Shortcut for `getUdtField(udt, CqlIdentifier.fromCql(fieldName))`.
`static Selector`	`field(String udtColumnName, String fieldName)` Shortcut for `field(CqlIdentifier.fromCql(udtColumnName), CqlIdentifier.fromCql(fieldName))`.
`static Selector`	`function(CqlIdentifier keyspaceId, CqlIdentifier functionId, Iterable<Selector> arguments)` Selects the result of a function call, as is `SELECT ks.f(a,b)`
`static Selector`	`function(CqlIdentifier keyspaceId, CqlIdentifier functionId, Selector... arguments)` Var-arg equivalent of `function(CqlIdentifier, CqlIdentifier, Iterable)`.
`static Selector`	`function(CqlIdentifier functionId, Iterable<Selector> arguments)` Selects the result of a function call, as is `SELECT f(a,b)`
`static Selector`	`function(CqlIdentifier functionId, Selector... arguments)` Var-arg equivalent of `function(CqlIdentifier, Iterable)`.
`static Selector`	`function(String functionName, Iterable<Selector> arguments)` Shortcut for `function(CqlIdentifier.fromCql(functionName), arguments)`.
`static Selector`	`function(String functionName, Selector... arguments)` Var-arg equivalent of `function(String, Iterable)`.
`static Selector`	`function(String keyspaceName, String functionName, Iterable<Selector> arguments)` Shortcut for `function(CqlIdentifier, CqlIdentifier, Iterable)` function(CqlIdentifier.fromCql(functionName), arguments)}.
`static Selector`	`function(String keyspaceName, String functionName, Selector... arguments)` Var-arg equivalent of `function(String, String, Iterable)`.
`CqlIdentifier`	`getAlias()`
`static Selector`	`listOf(Iterable<Selector> elementSelectors)` Selects a group of elements as a list, as in `SELECT [a,b,c]`.
`static Selector`	`listOf(Selector... elementSelectors)` Var-arg equivalent of `listOf(Iterable)`.
`static Selector`	`mapOf(Map<Selector,Selector> elementSelectors)` Selects a group of elements as a map, as in `SELECT {a:b,c:d}`.
`static Selector`	`mapOf(Map<Selector,Selector> elementSelectors, DataType keyType, DataType valueType)` Selects a group of elements as a map and force the resulting map type, as in `SELECT (map<int,text>){a:b,c:d}`.
`static Selector`	`multiply(Selector left, Selector right)` Selects the product of two arguments, as in `SELECT col1 * col2`.
`static Selector`	`negate(Selector argument)` Selects the opposite of an argument, as in `SELECT -col1`.
`static Selector`	`range(CqlIdentifier collectionId, Term left, Term right)` Shortcut for slice selection when the target collection is a simple column.
`static Selector`	`range(Selector collection, Term left, Term right)` Selects a slice in a collection column, as in `SELECT s[4..8]`.
`static Selector`	`range(String collectionName, Term left, Term right)` Shortcut for `range(CqlIdentifier.fromCql(collectionName), left, right)`.
`static Selector`	`remainder(Selector left, Selector right)` Selects the remainder of two arguments, as in `SELECT col1 % col2`.
`static Selector`	`setOf(Iterable<Selector> elementSelectors)` Selects a group of elements as a set, as in `SELECT {a,b,c}`.
`static Selector`	`setOf(Selector... elementSelectors)` Var-arg equivalent of `setOf(Iterable)`.
`static Selector`	`subtract(Selector left, Selector right)` Selects the difference of two arguments, as in `SELECT col1 - col2`.
`static Selector`	`toDate(CqlIdentifier columnId)` Shortcut to select the result of the built-in `toDate` function on a simple column.
`static Selector`	`toDate(String columnName)` Shortcut for `toDate(CqlIdentifier.fromCql(columnName))`.
`static Selector`	`toTimestamp(CqlIdentifier columnId)` Shortcut to select the result of the built-in `toTimestamp` function on a simple column.
`static Selector`	`toTimestamp(String columnName)` Shortcut for `toTimestamp(CqlIdentifier.fromCql(columnName))`.
`static Selector`	`toUnixTimestamp(CqlIdentifier columnId)` Shortcut to select the result of the built-in `toUnixTimestamp` function on a simple column.
`static Selector`	`toUnixTimestamp(String columnName)` Shortcut for `toUnixTimestamp(CqlIdentifier.fromCql(columnName))`.
`static Selector`	`ttl(CqlIdentifier columnId)` Shortcut to select the result of the built-in `ttl` function, as in `SELECT ttl(c)`.
`static Selector`	`ttl(String columnName)` Shortcut for `ttl(CqlIdentifier.fromCql(columnName))`.
`static Selector`	`tupleOf(Iterable<Selector> elementSelectors)` Selects a group of elements as a tuple, as in `SELECT (a,b,c)`.
`static Selector`	`tupleOf(Selector... elementSelectors)` Var-arg equivalent of `tupleOf(Iterable)`.
`static Selector`	`typeHint(Selector selector, DataType targetType)` Provides a type hint for a selector, as in `SELECT (double)1/3`.
`static Selector`	`writeTime(CqlIdentifier columnId)` Shortcut to select the result of the built-in `writetime` function, as in `SELECT writetime(c)`.
`static Selector`	`writeTime(String columnName)` Shortcut for `writeTime(CqlIdentifier.fromCql(columnName))`.

Methods inherited from interface com.datastax.oss.driver.api.querybuilder.CqlSnippet
appendTo

Method Detail

all
```
@NonNull
static Selector all()
```
Selects all columns, as in SELECT *.

countAll
```
@NonNull
static Selector countAll()
```
Selects the count of all returned rows, as in SELECT count(*).

column

@NonNull
static Selector column(@NonNull
                                CqlIdentifier columnId)

Selects a particular column by its CQL identifier.

column

@NonNull
static Selector column(@NonNull
                                String columnName)

Shortcut for column(CqlIdentifier.fromCql(columnName))

add

@NonNull
static Selector add(@NonNull
                             Selector left,
                             @NonNull
                             Selector right)

Selects the sum of two arguments, as in SELECT col1 + col2.

This is available in Cassandra 4 and above.

subtract

@NonNull
static Selector subtract(@NonNull
                                  Selector left,
                                  @NonNull
                                  Selector right)

Selects the difference of two arguments, as in SELECT col1 - col2.

This is available in Cassandra 4 and above.

multiply
```
@NonNull
static Selector multiply(@NonNull
                                  Selector left,
                                  @NonNull
                                  Selector right)
```
Selects the product of two arguments, as in SELECT col1 * col2.
This is available in Cassandra 4 and above.
The arguments will be parenthesized if they are instances of add(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector) or subtract(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector). If they are raw selectors, you might have to parenthesize them yourself.

divide
```
@NonNull
static Selector divide(@NonNull
                                Selector left,
                                @NonNull
                                Selector right)
```
Selects the quotient of two arguments, as in SELECT col1 / col2.
This is available in Cassandra 4 and above.
The arguments will be parenthesized if they are instances of add(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector) or subtract(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector). If they are raw selectors, you might have to parenthesize them yourself.

remainder
```
@NonNull
static Selector remainder(@NonNull
                                   Selector left,
                                   @NonNull
                                   Selector right)
```
Selects the remainder of two arguments, as in SELECT col1 % col2.
This is available in Cassandra 4 and above.
The arguments will be parenthesized if they are instances of add(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector) or subtract(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector). If they are raw selectors, you might have to parenthesize them yourself.

negate
```
@NonNull
static Selector negate(@NonNull
                                Selector argument)
```
Selects the opposite of an argument, as in SELECT -col1.
This is available in Cassandra 4 and above.
The argument will be parenthesized if it is an instance of add(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector) or subtract(com.datastax.oss.driver.api.querybuilder.select.Selector, com.datastax.oss.driver.api.querybuilder.select.Selector). If it is a raw selector, you might have to parenthesize it yourself.

field

@NonNull
static Selector field(@NonNull
                               Selector udt,
                               @NonNull
                               CqlIdentifier fieldId)

Selects a field inside of a UDT column, as in SELECT user.name.

field

@NonNull
static Selector field(@NonNull
                               Selector udt,
                               @NonNull
                               String fieldName)

Shortcut for

getUdtField(udt,
 CqlIdentifier.fromCql(fieldName))

field

@NonNull
static Selector field(@NonNull
                               CqlIdentifier udtColumnId,
                               @NonNull
                               CqlIdentifier fieldId)

Shortcut to select a UDT field when the UDT is a simple column (as opposed to a more complex selection, like a nested UDT).

field

@NonNull
static Selector field(@NonNull
                               String udtColumnName,
                               @NonNull
                               String fieldName)

Shortcut for field(CqlIdentifier.fromCql(udtColumnName), CqlIdentifier.fromCql(fieldName)).

element

@NonNull
static Selector element(@NonNull
                                 Selector collection,
                                 @NonNull
                                 Term index)

Selects an element in a collection column, as in SELECT m['key'].

As of Cassandra 4, this is only allowed in SELECT for map and set columns. DELETE accepts list elements as well.

element

@NonNull
static Selector element(@NonNull
                                 CqlIdentifier collectionId,
                                 @NonNull
                                 Term index)

Shortcut for element selection when the target collection is a simple column.

In other words, this is the equivalent of element(column(collectionId), index).

element

@NonNull
static Selector element(@NonNull
                                 String collectionName,
                                 @NonNull
                                 Term index)

Shortcut for element(CqlIdentifier.fromCql(collectionName), index).

range
```
@NonNull
static Selector range(@NonNull
                               Selector collection,
                               @Nullable
                               Term left,
                               @Nullable
                               Term right)
```
Selects a slice in a collection column, as in SELECT s[4..8].
As of Cassandra 4, this is only allowed for set and map columns. Those collections are ordered, the elements (or keys in the case of a map), will be compared to the bounds for inclusions. Either bound can be unspecified, but not both.

Parameters:

left - the left bound (inclusive). Can be null to indicate that the slice is only right-bound.

right - the right bound (inclusive). Can be null to indicate that the slice is only left-bound.

range

@NonNull
static Selector range(@NonNull
                               CqlIdentifier collectionId,
                               @Nullable
                               Term left,
                               @Nullable
                               Term right)

Shortcut for slice selection when the target collection is a simple column.

In other words, this is the equivalent of range(Selector, Term, Term) range(column(collectionId), left, right)}.

range

@NonNull
static Selector range(@NonNull
                               String collectionName,
                               @Nullable
                               Term left,
                               @Nullable
                               Term right)

Shortcut for range(CqlIdentifier.fromCql(collectionName), left, right).

listOf
```
@NonNull
static Selector listOf(@NonNull
                                Iterable<Selector> elementSelectors)
```
Selects a group of elements as a list, as in SELECT [a,b,c].
None of the selectors should be aliased (the query builder checks this at runtime), and they should all produce the same data type (the query builder can't check this, so the query will fail at execution time).

Throws:

IllegalArgumentException - if any of the selectors is aliased.

listOf

@NonNull
static Selector listOf(@NonNull
                                Selector... elementSelectors)

Var-arg equivalent of listOf(Iterable).

setOf
```
@NonNull
static Selector setOf(@NonNull
                               Iterable<Selector> elementSelectors)
```
Selects a group of elements as a set, as in SELECT {a,b,c}.
None of the selectors should be aliased (the query builder checks this at runtime), and they should all produce the same data type (the query builder can't check this, so the query will fail at execution time).

Throws:

IllegalArgumentException - if any of the selectors is aliased.

setOf

@NonNull
static Selector setOf(@NonNull
                               Selector... elementSelectors)

Var-arg equivalent of setOf(Iterable).

tupleOf
```
@NonNull
static Selector tupleOf(@NonNull
                                 Iterable<Selector> elementSelectors)
```
Selects a group of elements as a tuple, as in SELECT (a,b,c).
None of the selectors should be aliased (the query builder checks this at runtime).

Throws:

IllegalArgumentException - if any of the selectors is aliased.

tupleOf

@NonNull
static Selector tupleOf(@NonNull
                                 Selector... elementSelectors)

Var-arg equivalent of tupleOf(Iterable).

mapOf
```
@NonNull
static Selector mapOf(@NonNull
                               Map<Selector,Selector> elementSelectors)
```
Selects a group of elements as a map, as in SELECT {a:b,c:d}.
None of the selectors should be aliased (the query builder checks this at runtime). In addition, all key selectors should produce the same type, and all value selectors as well (the key and value types can be different); the query builder can't check this, so the query will fail at execution time if the types are not uniform.
Note that Cassandra often has trouble inferring the exact map type. This will manifest as the error message:
```
   Cannot infer type for term xxx in selection clause (try using a cast to force a type)
 
```
If you run into this, consider providing the types explicitly with mapOf(Map, DataType, DataType).
Throws:

IllegalArgumentException - if any of the selectors is aliased.

mapOf

@NonNull
static Selector mapOf(@NonNull
                               Map<Selector,Selector> elementSelectors,
                               @Nullable
                               DataType keyType,
                               @Nullable
                               DataType valueType)

Selects a group of elements as a map and force the resulting map type, as in

SELECT
 (map<int,text>){a:b,c:d}

To create the data types, use the constants and static methods in DataTypes, or QueryBuilder.udt(CqlIdentifier).

See Also:: mapOf(Map)

typeHint

@NonNull
static Selector typeHint(@NonNull
                                  Selector selector,
                                  @NonNull
                                  DataType targetType)

Provides a type hint for a selector, as in SELECT (double)1/3.

To create the data type, use the constants and static methods in DataTypes, or QueryBuilder.udt(CqlIdentifier).

function

@NonNull
static Selector function(@NonNull
                                  CqlIdentifier functionId,
                                  @NonNull
                                  Iterable<Selector> arguments)

Selects the result of a function call, as is SELECT f(a,b)

None of the arguments should be aliased (the query builder checks this at runtime).

Throws:: IllegalArgumentException - if any of the selectors is aliased.

function

@NonNull
static Selector function(@NonNull
                                  CqlIdentifier functionId,
                                  @NonNull
                                  Selector... arguments)

Var-arg equivalent of function(CqlIdentifier, Iterable).

function

@NonNull
static Selector function(@NonNull
                                  String functionName,
                                  @NonNull
                                  Iterable<Selector> arguments)

Shortcut for function(CqlIdentifier.fromCql(functionName), arguments).

function

@NonNull
static Selector function(@NonNull
                                  String functionName,
                                  @NonNull
                                  Selector... arguments)

Var-arg equivalent of function(String, Iterable).

function

@NonNull
static Selector function(@Nullable
                                  CqlIdentifier keyspaceId,
                                  @NonNull
                                  CqlIdentifier functionId,
                                  @NonNull
                                  Iterable<Selector> arguments)

Selects the result of a function call, as is SELECT ks.f(a,b)

None of the arguments should be aliased (the query builder checks this at runtime).

Throws:: IllegalArgumentException - if any of the selectors is aliased.

function

@NonNull
static Selector function(@Nullable
                                  CqlIdentifier keyspaceId,
                                  @NonNull
                                  CqlIdentifier functionId,
                                  @NonNull
                                  Selector... arguments)

Var-arg equivalent of function(CqlIdentifier, CqlIdentifier, Iterable).

function

@NonNull
static Selector function(@Nullable
                                  String keyspaceName,
                                  @NonNull
                                  String functionName,
                                  @NonNull
                                  Iterable<Selector> arguments)

Shortcut for function(CqlIdentifier, CqlIdentifier, Iterable) function(CqlIdentifier.fromCql(functionName), arguments)}.

function

@NonNull
static Selector function(@Nullable
                                  String keyspaceName,
                                  @NonNull
                                  String functionName,
                                  @NonNull
                                  Selector... arguments)

Var-arg equivalent of function(String, String, Iterable).

writeTime

@NonNull
static Selector writeTime(@NonNull
                                   CqlIdentifier columnId)

Shortcut to select the result of the built-in writetime function, as in

SELECT
 writetime(c)

writeTime

@NonNull
static Selector writeTime(@NonNull
                                   String columnName)

Shortcut for writeTime(CqlIdentifier.fromCql(columnName)).

ttl

@NonNull
static Selector ttl(@NonNull
                             CqlIdentifier columnId)

Shortcut to select the result of the built-in ttl function, as in

SELECT
 ttl(c)

ttl

@NonNull
static Selector ttl(@NonNull
                             String columnName)

Shortcut for ttl(CqlIdentifier.fromCql(columnName)).

cast

@NonNull
static Selector cast(@NonNull
                              Selector selector,
                              @NonNull
                              DataType targetType)

Casts a selector to a type, as in SELECT CAST(a AS double).

To create the data type, use the constants and static methods in DataTypes, or QueryBuilder.udt(CqlIdentifier).

Throws:: IllegalArgumentException - if the selector is aliased.

toDate

@NonNull
static Selector toDate(@NonNull
                                CqlIdentifier columnId)

Shortcut to select the result of the built-in toDate function on a simple column.

toDate

@NonNull
static Selector toDate(@NonNull
                                String columnName)

Shortcut for toDate(CqlIdentifier.fromCql(columnName)).

toTimestamp

@NonNull
static Selector toTimestamp(@NonNull
                                     CqlIdentifier columnId)

Shortcut to select the result of the built-in toTimestamp function on a simple column.

toTimestamp

@NonNull
static Selector toTimestamp(@NonNull
                                     String columnName)

Shortcut for toTimestamp(CqlIdentifier.fromCql(columnName)).

toUnixTimestamp

@NonNull
static Selector toUnixTimestamp(@NonNull
                                         CqlIdentifier columnId)

Shortcut to select the result of the built-in toUnixTimestamp function on a simple column.

toUnixTimestamp

@NonNull
static Selector toUnixTimestamp(@NonNull
                                         String columnName)

Shortcut for toUnixTimestamp(CqlIdentifier.fromCql(columnName)).

as

@NonNull
Selector as(@NonNull
                     CqlIdentifier alias)

Aliases the selector, as in SELECT count(*) AS total.

as

@NonNull
default Selector as(@NonNull
                             String alias)

Shortcut for as(CqlIdentifier.fromCql(alias))

getAlias
```
@Nullable
CqlIdentifier getAlias()
```
Returns:

null if the selector is not aliased.

Interface Selector

Method Summary

Methods inherited from interface com.datastax.oss.driver.api.querybuilder.CqlSnippet

Method Detail

all

countAll

column

column

add

subtract

multiply

divide

remainder

negate

field

field

field

field

element

element

element

range

range

range

listOf

listOf

setOf

setOf

tupleOf

tupleOf

mapOf

mapOf

typeHint

function

function

function

function

function

function

function

function

writeTime

writeTime

ttl

ttl

cast

toDate

toDate

toTimestamp

toTimestamp

toUnixTimestamp

toUnixTimestamp

as

as

getAlias