Module org.datanucleus.store.rdbms

Package org.datanucleus.store.rdbms.sql.expression

Class CollectionExpression

java.lang.Object

org.datanucleus.store.rdbms.sql.expression.SQLExpression

org.datanucleus.store.rdbms.sql.expression.CollectionExpression

Direct Known Subclasses:

CollectionLiteral

public class CollectionExpression
extends SQLExpression

An expression that represents some collection field in a query candidate class, or a collection field in an object linked from the candidate class by navigation.

When navigated through using contains(expr), the elements of the collection are relationally joined onto the query statement.

As this is a Collection Expression it works equally for Sets and Lists, and we use CollectionStore as the backing store interface, so that ListStore and SetStore are equally applicable.

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

SQLExpression.ColumnExpressionList

Field Summary

Fields inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

lowestOperator, mapping, parameterName, st, stmt, subExprs, table

Constructor Summary

Constructors

Constructor	Description
CollectionExpression(SQLStatement stmt, SQLTable table, JavaTypeMapping mapping)	Constructor for an SQL expression for a (field) mapping in a specified table.

Method Summary

Modifier and Type	Method	Description
BooleanExpression	eq(SQLExpression expr)	Method to return the expression for comparing a collection with a value.
SQLExpression	invoke(String methodName, List args)	Invocation of a method on this expression.
BooleanExpression	ne(SQLExpression expr)	Method to return the expression for comparing a collection with a value.

Methods inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

add, and, bitAnd, bitOr, cast, com, distinct, div, encloseInParentheses, eor, ge, getJavaTypeMapping, getLowestOperator, getNumberOfSubExpressions, getParameterName, getSQLStatement, getSQLTable, getSubExpression, gt, in, ior, is, isParameter, le, lt, mod, mul, neg, not, setJavaTypeMapping, sub, toSQLText, unDistinct

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionExpression

public CollectionExpression(SQLStatement stmt,
                            SQLTable table,
                            JavaTypeMapping mapping)

Constructor for an SQL expression for a (field) mapping in a specified table.

Parameters:

stmt - The statement

table - The table in the statement

mapping - The mapping for the field

Method Detail

invoke

public SQLExpression invoke(String methodName,
                            List args)

Description copied from class: SQLExpression

Invocation of a method on this expression.

Overrides:

invoke in class SQLExpression

Parameters:

methodName - name of the method to invoke

args - Args to this method (if any)

Returns:

the converted value

eq

public BooleanExpression eq(SQLExpression expr)

Method to return the expression for comparing a collection with a value. Only supports comparisons with null currently.

Overrides:

eq in class SQLExpression

Parameters:

expr - The value to compare with.

Returns:

The expression of equality

ne

public BooleanExpression ne(SQLExpression expr)

Method to return the expression for comparing a collection with a value. Only supports comparisons with null currently.

Overrides:

ne in class SQLExpression

Parameters:

expr - The value to compare with.

Returns:

The expression of inequality