org.datanucleus.store.rdbms.sql.expression
Class MapExpression

java.lang.Object
  org.datanucleus.store.rdbms.sql.expression.SQLExpression
      org.datanucleus.store.rdbms.sql.expression.MapExpression

Direct Known Subclasses:

MapLiteral

public class MapExpression
extends SQLExpression

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

When navigated through using containsKey(expr) the keys of the Map are relationally joined onto the query statement. When navigated through using containsValue(expr) the values of the Map are relationally joined onto the query statement. These 2 methods are required for JDO 2.0, whilst the isEmpty() and contains() are JDO 1.0.1. containsEntry() is an extension.

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

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

Constructor Summary

MapExpression(SQLStatement stmt, SQLTable table, org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)
Constructor.

Method Summary

BooleanExpression	eq(SQLExpression expr) Method to return the expression for comparing a map 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 map with a value.

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

add, and, 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

Methods inherited from class java.lang.Object

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

Constructor Detail

MapExpression

public MapExpression(SQLStatement stmt,
                     SQLTable table,
                     org.datanucleus.store.mapped.mapping.JavaTypeMapping mapping)

Constructor.

Parameters:

stmt - The SQL Statement

table - Table containing the map field

mapping - The java field mapping

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 map 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 map 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