org.eclipse.persistence.expressions

Class ExpressionBuilder

java.lang.Object

org.eclipse.persistence.expressions.Expression

org.eclipse.persistence.internal.expressions.BaseExpression

org.eclipse.persistence.internal.expressions.DataExpression

org.eclipse.persistence.internal.expressions.ObjectExpression

org.eclipse.persistence.expressions.ExpressionBuilder

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

public class ExpressionBuilder
extends ObjectExpression

Purpose: Allow for instances of expression to be created. Expressions are Java object-level representations of SQL "where" clauses. The expressions attempt to mirror Java code as closely as possible.

Example:

        ExpressionBuilder employee = new ExpressionBuilder();
        employee.get("firstName").equal("Bob").and(employee.get("lastName").equal("Smith"))

         >> equivalent Java code: (employee.getFirstName().equals("Bob"))  && (employee.getLastName().equals("Smith"))

         >> equivalent SQL: (F_NAME = 'Bob') AND (L_NAME = 'Smith')
 

See Also:

Expression, Serialized Form

Field Summary

Fields inherited from class org.eclipse.persistence.internal.expressions.ObjectExpression

derivedExpressions

Fields inherited from class org.eclipse.persistence.expressions.Expression

shouldUseUpperCaseForIgnoreCase

Constructor Summary

Constructors

Constructor and Description
ExpressionBuilder() PUBLIC: Create a new ExpressionBuilder.
ExpressionBuilder(java.lang.Class queryClass) ADVANCED: Create a new ExpressionBuilder representing instances of the argument class.

Method Summary

Modifier and Type	Method and Description
DatabaseTable	aliasForTable(DatabaseTable table) INTERNAL: Find the alias for a given table.
int	assignTableAliasesStartingAt(int initialValue) INTERNAL: Assign aliases to any tables which I own.
java.lang.String	descriptionOfNodeType() INTERNAL: Used for debug printing.
boolean	doesNotRepresentAnObjectInTheQuery() INTERNAL: There are cases (which we might want to eliminate?) where the expression builder doesn't actually correspond to an object to be read.
boolean	equals(java.lang.Object expression) INTERNAL: Return if the expression is equal to the other.
DatabaseTable	getAliasedViewTable() INTERNAL:
ExpressionBuilder	getBuilder() INTERNAL: Return the expression builder which is the ultimate base of this expression, or null if there isn't one (shouldn't happen if we start from a root)
ClassDescriptor	getDescriptor() INTERNAL: Only usable after the session and class have been set.
ClassDescriptor	getLeafDescriptor(DatabaseQuery query, ClassDescriptor rootDescriptor, AbstractSession session) INTERNAL: Lookup the descriptor for this item by traversing its expression recursively.
java.lang.Class	getQueryClass() INTERNAL:
AbstractSession	getSession() INTERNAL:
SQLSelectStatement	getStatement() INTERNAL: Return the statement that expression is for.
DatabaseTable	getViewTable() INTERNAL:
boolean	hasViewTable() INTERNAL:
boolean	isExpressionBuilder() INTERNAL:
Expression	normalize(ExpressionNormalizer normalizer) INTERNAL: Normalize the expression into a printable structure.
void	printJava(ExpressionJavaPrinter printer) INTERNAL: Print java
Expression	rebuildOn(Expression newBase) INTERNAL: This expression is built on a different base than the one we want.
void	resetPlaceHolderBuilder(ExpressionBuilder queryBuilder) INTERNAL: Search the tree for any expressions (like SubSelectExpressions) that have been built using a builder that is not attached to the query.
void	setQueryClass(java.lang.Class queryClass) INTERNAL: Set the class which this node represents.
void	setQueryClassAndDescriptor(java.lang.Class queryClass, ClassDescriptor descriptor) INTERNAL: Set the class and descriptor which this node represents.
void	setSession(AbstractSession session) INTERNAL: Set the session in which we expect this expression to be translated.
void	setStatement(SQLSelectStatement statement) INTERNAL: Set the statement that expression is for.
void	setViewTable(DatabaseTable theTable) INTERNAL: This expression represents something read through a view table.
void	setWasAdditionJoinCriteriaUsed(boolean joinCriteriaUsed) INTERNAL: If the additional Join Criteria for the class this builder represents has been added to the statement then mark this as true.
Expression	twistedForBaseAndContext(Expression newBase, Expression context, Expression oldBase) INTERNAL: Rebuild myself against the base, with the values of parameters supplied by the context expression.
java.lang.Object	valueFromObject(java.lang.Object object, AbstractSession session, AbstractRecord translationRow, int valueHolderPolicy, boolean isObjectUnregistered) INTERNAL: The expression builder represent the entire object, just return it.
boolean	wasAdditionJoinCriteriaUsed() INTERNAL: If the additional Join Criteria for the class this builder represents has been added to the statement this method will return true;
boolean	wasQueryClassSetInternally() INTERNAL: Returns true if TopLink set the query class as opposed to the customer.
void	writeDescriptionOn(java.io.BufferedWriter writer) INTERNAL: For debug printing purposes.

Methods inherited from class org.eclipse.persistence.internal.expressions.ObjectExpression

addDerivedExpression, additionalExpressionCriteria, additionalExpressionCriteriaMap, anyOf, anyOfAllowingNone, clearAliases, convertToCastDescriptor, copyDerivedExpressions, derivedExpressionNamed, derivedManualExpressionNamed, doNotUseOuterJoin, doUseOuterJoin, existingDerivedExpressionNamed, get, getAdditionalTables, getAllowingNull, getCastClass, getFields, getFirstNonAggregateExpressionAfterExpressionBuilder, getJoinSource, getManualQueryKey, getOnClause, getOuterJoinExpIndex, getOwnedTables, getRelationTable, getSelectionFields, hasBeenAliased, isDirectCollection, isDowncast, isObjectExpression, isTreatUsed, isUsingOuterJoinForMultitableInheritance, join, leftJoin, newDerivedExpressionNamed, newManualDerivedExpressionNamed, postCopyIn, setCastClass, setJoinSource, setOnClause, setOuterJoinExpIndex, setShouldUseOuterJoinForMultitableInheritance, shouldUseOuterJoin, shouldUseOuterJoinForMultitableInheritance, treat, type

Methods inherited from class org.eclipse.persistence.internal.expressions.DataExpression

addDerivedField, addDerivedTable, asOf, copyCollection, existingDerivedField, existingDerivedTable, getAlias, getAliasedField, getAsOfClause, getContainingDescriptor, getField, getField, getField, getMapping, getQueryKeyOrNull, getTable, getTable, getTableAliases, hasAsOfClause, hasBeenNormalized, isAttribute, isDataExpression, iterateOn, newDerivedField, newDerivedTable, printSQL, setHasBeenNormalized, setTableAliases, tableAliasesDescription, writeSubexpressionsTo

Methods inherited from class org.eclipse.persistence.internal.expressions.BaseExpression

getBaseExpression, setBaseExpression, shallowClone

Methods inherited from class org.eclipse.persistence.expressions.Expression

addDate, addDate, addMonths, addMonths, alias, all, all, all, all, all, all, all, all, all, all, all, all, all, allOf, and, any, any, any, any, any, any, any, any, any, any, any, any, any, anyOf, anyOfAllowingNone, as, as, ascending, asciiValue, average, between, between, between, between, between, between, between, between, between, caseConditionStatement, caseConditionStatement, caseStatement, caseStatement, cast, clone, cloneUsing, coalesce, coalesce, computeHashCode, concat, containsAllKeyWords, containsAnyKeyWords, containsSubstring, containsSubstring, containsSubstringIgnoringCase, containsSubstringIgnoringCase, convertToUseOuterJoin, copiedVersionFrom, count, create, create, createWithBaseLast, currentDate, currentDateDate, currentTime, currentTimeStamp, dateDifference, dateDifference, dateName, datePart, dateToString, decode, descending, difference, distinct, doesConform, doesConform, equal, equal, equal, equal, equal, equal, equal, equal, equal, equal, equalOuterJoin, equalOuterJoin, equalsIgnoreCase, equalsIgnoreCase, except, except, exceptAll, exceptAll, exists, existsNode, extract, extractFields, extractPrimaryKeyValues, extractValue, extractValues, extractXml, from, fromConstant, fromLiteral, get, getAsOfClauseRecursively, getClonedField, getFieldValue, getFunction, getFunction, getFunction, getFunction, getFunction, getFunctionWithArguments, getFunctionWithArguments, getLeafMapping, getName, getNumberVal, getOperator, getOperator, getParameter, getParameter, getParameter, getProperty, getSelectionFields, getStringVal, greaterThan, greaterThan, greaterThan, greaterThan, greaterThan, greaterThan, greaterThan, greaterThan, greaterThan, greaterThan, greaterThanEqual, greaterThanEqual, greaterThanEqual, greaterThanEqual, greaterThanEqual, greaterThanEqual, greaterThanEqual, greaterThanEqual, greaterThanEqual, greaterThanEqual, hashCode, hexToRaw, ifNull, in, in, in, in, in, in, in, in, in, in, in, in, index, indexOf, intersect, intersect, intersectAll, intersectAll, isClassTypeExpression, isCompoundExpression, isConstantExpression, isEmpty, isFieldExpression, isFragment, isFunctionExpression, isLiteralExpression, isLogicalExpression, isMapEntryExpression, isNull, isParameterExpression, isQueryKeyExpression, isRelationExpression, isSubSelectExpression, isTableExpression, isTreatExpression, isValueExpression, lastDay, leftPad, leftPad, leftTrim, leftTrim, length, lessThan, lessThan, lessThan, lessThan, lessThan, lessThan, lessThan, lessThan, lessThan, lessThan, lessThanEqual, lessThanEqual, lessThanEqual, lessThanEqual, lessThanEqual, lessThanEqual, lessThanEqual, lessThanEqual, lessThanEqual, lessThanEqual, like, like, like, like, likeIgnoreCase, likeIgnoreCase, literal, locate, locate, locate, mapEntry, mapKey, maximum, minimum, monthsBetween, newTime, nextDay, noneOf, not, notBetween, notBetween, notBetween, notBetween, notBetween, notBetween, notBetween, notBetween, notBetween, notEmpty, notEqual, notEqual, notEqual, notEqual, notEqual, notEqual, notEqual, notEqual, notEqual, notEqual, notExists, notIn, notIn, notIn, notIn, notIn, notIn, notIn, notIn, notIn, notIn, notIn, notIn, notLike, notLike, notLike, notLike, notNull, nullIf, nullsFirst, nullsLast, operator, or, performOperator, postfixSQL, prefixSQL, ref, regexp, regexp, replace, replicate, replicate, reverse, right, right, rightPad, rightPad, rightTrim, rightTrim, roundDate, selectIfOrderedBy, setLocalBase, setSelectIfOrderedBy, size, size, some, some, some, some, some, some, some, some, some, some, some, some, some, sql, standardDeviation, subQuery, substring, substring, substring, substring, sum, toChar, toChar, toCharacter, toDate, toLowerCase, toNumber, toString, toString, toUpperCase, toUppercaseCasedWords, translate, trim, trim, truncateDate, twist, union, union, unionAll, unionAll, validateNode, value, value, value, value, value, value, value, value, value, value, valueFromObject, variance, writeFields

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

ExpressionBuilder

public ExpressionBuilder()

PUBLIC: Create a new ExpressionBuilder.

ExpressionBuilder

public ExpressionBuilder(java.lang.Class queryClass)

ADVANCED: Create a new ExpressionBuilder representing instances of the argument class. This can be used for the purpose of parallel expressions. This is a type of query that searches on the relationship between to un-related objects.

Method Detail

equals

public boolean equals(java.lang.Object expression)

INTERNAL: Return if the expression is equal to the other. This is used to allow dynamic expression's SQL to be cached.

Overrides:

equals in class ObjectExpression

aliasForTable

public DatabaseTable aliasForTable(DatabaseTable table)

INTERNAL: Find the alias for a given table. Handle the special case where we are bogus and it should be aliased against our derived tables instead.

Overrides:

aliasForTable in class DataExpression

assignTableAliasesStartingAt

public int assignTableAliasesStartingAt(int initialValue)

INTERNAL: Assign aliases to any tables which I own. Start with t(initialValue), and return the new value of the counter , i.e. if initialValue is one and I have tables ADDRESS and EMPLOYEE I will assign them t1 and t2 respectively, and return 3.

Overrides:

assignTableAliasesStartingAt in class ObjectExpression

descriptionOfNodeType

public java.lang.String descriptionOfNodeType()

INTERNAL: Used for debug printing.

Overrides:

descriptionOfNodeType in class Expression

doesNotRepresentAnObjectInTheQuery

public boolean doesNotRepresentAnObjectInTheQuery()

INTERNAL: There are cases (which we might want to eliminate?) where the expression builder doesn't actually correspond to an object to be read. Mostly this is the case where it's a data query in terms of tables, and the builder is only there to provide a base. It might be better to make tables able to serve as their own base, but it's very nice to have a known unique, shared base. In the meantime, this is a special case to make sure the builder doesn't get tables assigned.

getAliasedViewTable

public DatabaseTable getAliasedViewTable()

INTERNAL:

getBuilder

public ExpressionBuilder getBuilder()

INTERNAL: Return the expression builder which is the ultimate base of this expression, or null if there isn't one (shouldn't happen if we start from a root)

Overrides:

getBuilder in class BaseExpression

getDescriptor

public ClassDescriptor getDescriptor()

INTERNAL: Only usable after the session and class have been set. Return the descriptor for the class this node represents.

Overrides:

getDescriptor in class ObjectExpression

getQueryClass

public java.lang.Class getQueryClass()

INTERNAL:

getSession

public AbstractSession getSession()

INTERNAL:

Overrides:

getSession in class Expression

getStatement

public SQLSelectStatement getStatement()

INTERNAL: Return the statement that expression is for. This is used for the context in subselects.

getViewTable

public DatabaseTable getViewTable()

INTERNAL:

hasViewTable

public boolean hasViewTable()

INTERNAL:

isExpressionBuilder

public boolean isExpressionBuilder()

INTERNAL:

Overrides:

isExpressionBuilder in class Expression

normalize

public Expression normalize(ExpressionNormalizer normalizer)

INTERNAL: Normalize the expression into a printable structure. Any joins must be added to form a new root.

Overrides:

normalize in class DataExpression

printJava

public void printJava(ExpressionJavaPrinter printer)

INTERNAL: Print java

Overrides:

printJava in class Expression

rebuildOn

public Expression rebuildOn(Expression newBase)

INTERNAL: This expression is built on a different base than the one we want. Rebuild it and return the root of the new tree This assumes that the original expression has only a single builder.

Specified by:

rebuildOn in class Expression

See Also:

Expression.cloneUsing(Expression newBase)

resetPlaceHolderBuilder

public void resetPlaceHolderBuilder(ExpressionBuilder queryBuilder)

INTERNAL: Search the tree for any expressions (like SubSelectExpressions) that have been built using a builder that is not attached to the query. This happens in case of an Exists call using a new ExpressionBuilder(). This builder needs to be replaced with one from the query.

Overrides:

resetPlaceHolderBuilder in class BaseExpression

setQueryClass

public void setQueryClass(java.lang.Class queryClass)

INTERNAL: Set the class which this node represents.

setQueryClassAndDescriptor

public void setQueryClassAndDescriptor(java.lang.Class queryClass,
                                       ClassDescriptor descriptor)

INTERNAL: Set the class and descriptor which this node represents.

setSession

public void setSession(AbstractSession session)

INTERNAL: Set the session in which we expect this expression to be translated. Stored session shall always be root session.

setStatement

public void setStatement(SQLSelectStatement statement)

INTERNAL: Set the statement that expression is for. This is used for the context in subselects.

setViewTable

public void setViewTable(DatabaseTable theTable)

INTERNAL: This expression represents something read through a view table.

setWasAdditionJoinCriteriaUsed

public void setWasAdditionJoinCriteriaUsed(boolean joinCriteriaUsed)

INTERNAL: If the additional Join Criteria for the class this builder represents has been added to the statement then mark this as true. This will prevent TopLink from adding it again at normalization

twistedForBaseAndContext

public Expression twistedForBaseAndContext(Expression newBase,
                                           Expression context,
                                           Expression oldBase)

INTERNAL: Rebuild myself against the base, with the values of parameters supplied by the context expression. This is used for transforming a standalone expression (e.g. the join criteria of a mapping) into part of some larger expression. You normally would not call this directly, instead calling twist See the comment there for more details.

Overrides:

twistedForBaseAndContext in class Expression

valueFromObject

public java.lang.Object valueFromObject(java.lang.Object object,
                                        AbstractSession session,
                                        AbstractRecord translationRow,
                                        int valueHolderPolicy,
                                        boolean isObjectUnregistered)

INTERNAL: The expression builder represent the entire object, just return it.

Overrides:

valueFromObject in class Expression

isObjectUnregistered - true if object possibly not a clone, but is being conformed against the unit of work cache.

wasAdditionJoinCriteriaUsed

public boolean wasAdditionJoinCriteriaUsed()

INTERNAL: If the additional Join Criteria for the class this builder represents has been added to the statement this method will return true;

wasQueryClassSetInternally

public boolean wasQueryClassSetInternally()

INTERNAL: Returns true if TopLink set the query class as opposed to the customer. This is important in determining if this Expression should be treated as a parallel expression during normalization

getLeafDescriptor

public ClassDescriptor getLeafDescriptor(DatabaseQuery query,
                                         ClassDescriptor rootDescriptor,
                                         AbstractSession session)

INTERNAL: Lookup the descriptor for this item by traversing its expression recursively.

Overrides:

getLeafDescriptor in class Expression

writeDescriptionOn

public void writeDescriptionOn(java.io.BufferedWriter writer)
                        throws java.io.IOException

INTERNAL: For debug printing purposes.

Overrides:

writeDescriptionOn in class Expression

Throws:

java.io.IOException