uk.ac.ed.epcc.webapp.jdbc.expr

Interface SQLExpression<T>

Type Parameters:

T - Java Type generated by expression

All Superinterfaces:

GroupingSQLValue<T>, SQLValue<T>, Targetted<T>

All Known Subinterfaces:

DateSQLExpression, FieldSQLExpression<T,X>, WrappedSQLExpression<T>

All Known Implementing Classes:

ArrayFuncExpression, BinaryExpression, BooleanFieldExpression, CaseExpression, CastDoubleSQLExpression, CastLongSQLExpression, CompareSQLExpression, ConcatSQLExpression, ConstExpression, CountDistinctExpression, DateDerefSQLExpression, DateFieldExpression, DerefSQLExpression, DurationSQLExpression, FieldExpression, FuncExpression, LengthExpression, LocateSQLExpression, MysqlDateConverter, MysqlMillisecondConverter, MysqlSQLHashExpression, MysqlTimestampDiffExpr, NumberFieldExpression, PostgresqlDateConverter, PostgresqlMillisecondConverter, RoundSQLExpression, SelfIdExpression, StreamDataFieldExpression, StringConvertSQLExpression, StringFieldExpression, TimestampDateFieldExpression

public interface SQLExpression<T>
extends GroupingSQLValue<T>

An object that can produce a SQL expression suitable for use in a select statement. Though functionally the same as SQLValue when objects implement this interface the SQL fragment and the returned object should be equivalent allowing SQLExpressions to be combined together in java or in SQL without changing the meaning of the expression. SQLExpressions have to only generate a single result field so the add method must return 1;

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
default boolean	groupingIsomorphic() Is there always a one-to-one mapping between groups and values
int	hashCode()

Methods inherited from interface uk.ac.ed.epcc.webapp.jdbc.expr.GroupingSQLValue

addGroup, checkContentsCanGroup, getGroupParameters

Methods inherited from interface uk.ac.ed.epcc.webapp.jdbc.expr.SQLValue

add, getParameters, getRequiredFilter, makeObject

Methods inherited from interface uk.ac.ed.epcc.webapp.Targetted

getTarget

Method Detail

hashCode

int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

groupingIsomorphic

default boolean groupingIsomorphic()

Description copied from interface: GroupingSQLValue

Is there always a one-to-one mapping between groups and values

Specified by:

groupingIsomorphic in interface GroupingSQLValue<T>

Returns: