Package org.hibernate.query.sqm.function

Interface SqmFunctionDescriptor

All Known Implementing Classes:

AbstractSqmFunctionDescriptor, AbstractSqmSelfRenderingFunctionDescriptor, AvgFunction, CaseLeastGreatestEmulation, CastFunction, CastingConcatFunction, CastStrEmulation, ChrLiteralEmulation, CoalesceIfnullEmulation, ConcatPipeFunction, CountFunction, CurrentFunction, DB2FormatEmulation, DB2PositionFunction, DB2SubstringFunction, DerbyLpadEmulation, DerbyRpadEmulation, EveryAnyEmulation, ExtractFunction, FormatFunction, HANASpatialAggregate, HANASpatialFunction, HypotheticalSetFunction, HypotheticalSetWindowEmulation, InsertSubstringOverlayEmulation, IntegralTimestampaddFunction, InverseDistributionFunction, InverseDistributionWindowEmulation, JdbcEscapeFunctionDescriptor, LengthFunction, ListaggFunction, ListaggGroupConcatEmulation, ListaggStringAggEmulation, LocatePositionEmulation, LpadRpadPadEmulation, MinMaxCaseEveryAnyEmulation, ModeStatsModeEmulation, MultipatternSqmFunctionDescriptor, NamedSqmFunctionDescriptor, NvlCoalesceEmulation, OracleSpatialFunction, OracleSpatialSQLMMFunction, OrderByFragmentFunction, PatternBasedSqmFunctionDescriptor, PostgreSQLMinMaxFunction, QuantifiedLeastGreatestEmulation, SDOGetGeometryType, SDOMethodDescriptor, SDORelateFunction, SqlFunction, SQLServerEveryAnyEmulation, SQLServerFormatEmulation, StandardSQLFunction, STRelateFunction, TimestampaddFunction, TimestampdiffFunction, TransactSQLStrFunction, TrimFunction

public interface SqmFunctionDescriptor

A factory for SQM nodes representing invocations of a certain named function. When a function names and arguments are encountered in the HQL, a SqmFunctionDescriptor for the given name is obtained from a SqmFunctionRegistry, and the generateSqmExpression(java.util.List<? extends org.hibernate.query.sqm.tree.SqmTypedNode<?>>, org.hibernate.query.ReturnableType<T>, org.hibernate.query.spi.QueryEngine, org.hibernate.type.spi.TypeConfiguration) method is called with the given argument SQM nodes to produce a subtree of SQM nodes representing the function invocation.

Method Summary

Modifier and Type	Method	Description
default boolean	alwaysIncludesParentheses()	Will a call to the described function always include parentheses?
default <T> SelfRenderingSqmFunction<T>	generateAggregateSqmExpression(List<? extends SqmTypedNode<?>> arguments, SqmPredicate filter, ReturnableType<T> impliedResultType, QueryEngine queryEngine, TypeConfiguration typeConfiguration)	Like generateSqmExpression(List, ReturnableType, QueryEngine, TypeConfiguration) but also accepts a filter predicate.
default <T> SelfRenderingSqmFunction<T>	generateOrderedSetAggregateSqmExpression(List<? extends SqmTypedNode<?>> arguments, SqmPredicate filter, SqmOrderByClause withinGroupClause, ReturnableType<T> impliedResultType, QueryEngine queryEngine, TypeConfiguration typeConfiguration)	Like generateSqmExpression(List, ReturnableType, QueryEngine, TypeConfiguration) but also accepts a filter predicate.
<T> SelfRenderingSqmFunction<T>	generateSqmExpression(List<? extends SqmTypedNode<?>> arguments, ReturnableType<T> impliedResultType, QueryEngine queryEngine, TypeConfiguration typeConfiguration)	Instantiate this template with the given arguments and expected return type.
default <T> SelfRenderingSqmFunction<T>	generateSqmExpression(ReturnableType<T> impliedResultType, QueryEngine queryEngine, TypeConfiguration typeConfiguration)	Convenience for no arguments
default <T> SelfRenderingSqmFunction<T>	generateSqmExpression(SqmTypedNode<?> argument, ReturnableType<T> impliedResultType, QueryEngine queryEngine, TypeConfiguration typeConfiguration)	Convenience for single argument
default <T> SelfRenderingSqmFunction<T>	generateWindowSqmExpression(List<? extends SqmTypedNode<?>> arguments, SqmPredicate filter, Boolean respectNulls, Boolean fromFirst, ReturnableType<T> impliedResultType, QueryEngine queryEngine, TypeConfiguration typeConfiguration)	Like generateSqmExpression(List, ReturnableType, QueryEngine, TypeConfiguration) but also accepts a filter predicate.
ArgumentsValidator	getArgumentsValidator()
default FunctionKind	getFunctionKind()
default String	getSignature(String name)

Method Detail

generateSqmExpression

<T> SelfRenderingSqmFunction<T> generateSqmExpression(List<? extends SqmTypedNode<?>> arguments,
                                                      ReturnableType<T> impliedResultType,
                                                      QueryEngine queryEngine,
                                                      TypeConfiguration typeConfiguration)

Instantiate this template with the given arguments and expected return type. This produces a tree of SQM nodes representing a tree of function invocations. This allows a single HQL function to be defined in terms of other predefined (database independent) HQL functions, simplifying the task of writing HQL functions which are portable between databases.

generateAggregateSqmExpression

default <T> SelfRenderingSqmFunction<T> generateAggregateSqmExpression(List<? extends SqmTypedNode<?>> arguments,
                                                                       SqmPredicate filter,
                                                                       ReturnableType<T> impliedResultType,
                                                                       QueryEngine queryEngine,
                                                                       TypeConfiguration typeConfiguration)

Like generateSqmExpression(List, ReturnableType, QueryEngine, TypeConfiguration) but also accepts a filter predicate. This method is intended for aggregate functions.

generateOrderedSetAggregateSqmExpression

default <T> SelfRenderingSqmFunction<T> generateOrderedSetAggregateSqmExpression(List<? extends SqmTypedNode<?>> arguments,
                                                                                 SqmPredicate filter,
                                                                                 SqmOrderByClause withinGroupClause,
                                                                                 ReturnableType<T> impliedResultType,
                                                                                 QueryEngine queryEngine,
                                                                                 TypeConfiguration typeConfiguration)

Like generateSqmExpression(List, ReturnableType, QueryEngine, TypeConfiguration) but also accepts a filter predicate. This method is intended for ordered set-aggregate functions.

generateWindowSqmExpression

default <T> SelfRenderingSqmFunction<T> generateWindowSqmExpression(List<? extends SqmTypedNode<?>> arguments,
                                                                    SqmPredicate filter,
                                                                    Boolean respectNulls,
                                                                    Boolean fromFirst,
                                                                    ReturnableType<T> impliedResultType,
                                                                    QueryEngine queryEngine,
                                                                    TypeConfiguration typeConfiguration)

Like generateSqmExpression(List, ReturnableType, QueryEngine, TypeConfiguration) but also accepts a filter predicate. This method is intended for aggregate functions.

generateSqmExpression

default <T> SelfRenderingSqmFunction<T> generateSqmExpression(SqmTypedNode<?> argument,
                                                              ReturnableType<T> impliedResultType,
                                                              QueryEngine queryEngine,
                                                              TypeConfiguration typeConfiguration)

Convenience for single argument

generateSqmExpression

default <T> SelfRenderingSqmFunction<T> generateSqmExpression(ReturnableType<T> impliedResultType,
                                                              QueryEngine queryEngine,
                                                              TypeConfiguration typeConfiguration)

Convenience for no arguments

alwaysIncludesParentheses

default boolean alwaysIncludesParentheses()

Will a call to the described function always include parentheses?

SqmFunctionTemplate is generally used for rendering of a function. However there are cases where Hibernate needs to consume a fragment and decide if a token represents a function name. In cases where the token is followed by an open-paren we can safely assume the token is a function name. However, if the next token is not an open-paren, the token can still represent a function provided that the function has a "no paren" form in the case of no arguments. E.g. Many databases do not require parentheses on functions like `current_timestamp`, etc. This method helps account for those cases.

Note that the most common case, by far, is that a function will always include the parentheses - therefore this return is defined as true by default. see Template#isFunction

getSignature

default String getSignature(String name)

getFunctionKind

default FunctionKind getFunctionKind()

getArgumentsValidator

ArgumentsValidator getArgumentsValidator()