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/*
* Copyright (c) 1998, 2022 Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2022 IBM Corporation. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
// IBM - Bug 537795: CASE THEN and ELSE scalar expression Constants should not be casted to CASE operand type
package org.eclipse.persistence.internal.expressions;
import java.io.*;
import java.util.*;
import org.eclipse.persistence.internal.helper.*;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.queries.*;
import org.eclipse.persistence.exceptions.*;
import org.eclipse.persistence.expressions.*;
import org.eclipse.persistence.internal.databaseaccess.*;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
/**
* Purpose: Expression SQL printer.
*
Responsibilities:
* - Print an expression in SQL format.
*
- Replaces FIELD types with field names from the descriptor.
*
- Replaces PARAMETER types with row or object values.
*
- Calls accessor to print primitive types.
*
* @author Dorin Sandu
* @since TOPLink/Java 1.0
*/
public class ExpressionSQLPrinter {
private static final String NULL_STRING = "NULL";
/**
* Stores the current session. The session accessor
* is used to print all the primitive types.
*/
protected AbstractSession session;
/**
* Stores the current platform to access platform specific functions.
*/
protected DatabasePlatform platform;
/**
* Stores the call being created.
*/
protected SQLCall call;
/**
* Stores the row. Used to print PARAMETER nodes.
*/
protected AbstractRecord translationRow;
/**
* Indicates whether fully qualified field names
* (owner + table) should be used or not.
*/
protected boolean shouldPrintQualifiedNames;
// What we write on
protected Writer writer;
/** Used for distincts in functions. */
protected boolean requiresDistinct;
// Used in figuring out when to print a comma in the select line
protected boolean isFirstElementPrinted;
public ExpressionSQLPrinter(AbstractSession session, AbstractRecord translationRow, SQLCall call, boolean printQualifiedNames, ExpressionBuilder builder) {
this.session = session;
this.translationRow = translationRow;
this.call = call;
this.shouldPrintQualifiedNames = printQualifiedNames;
// reference session's platform directly if builder or builder's descriptor is null
if (builder == null || builder.getDescriptor() == null) {
this.platform = getSession().getPlatform();
} else {
this.platform = (DatabasePlatform) getSession().getPlatform(builder.getDescriptor().getJavaClass());
}
this.requiresDistinct = false;
isFirstElementPrinted = false;
}
/**
* Return the call.
*/
public SQLCall getCall() {
return call;
}
/**
* INTERNAL:
* Return the database platform specific information.
*/
public DatabasePlatform getPlatform() {
return this.platform;
}
protected AbstractSession getSession() {
return session;
}
/**
* INTERNAL:
* Return the row for translation
*/
protected AbstractRecord getTranslationRow() {
return translationRow;
}
public Writer getWriter() {
return writer;
}
/**
* INTERNAL:
* Used in figuring out when to print a comma in the select clause
*/
public boolean isFirstElementPrinted() {
return isFirstElementPrinted;
}
public void printExpression(Expression expression) {
translateExpression(expression);
}
public void printField(DatabaseField field) {
if (field == null) {
return;
}
try {
// Print the field using either short or long notation i.e. owner + table name.
if (shouldPrintQualifiedNames()) {
getWriter().write(field.getQualifiedNameDelimited(platform));
} else {
getWriter().write(field.getNameDelimited(platform));
}
} catch (IOException exception) {
throw ValidationException.fileError(exception);
}
}
public void printField(DatabaseField field, DatabaseTable tableAlias) {
if (field == null) {
return;
}
try {
// Print the field using either short or long notation i.e. owner + table name.
if (shouldPrintQualifiedNames()) {
getWriter().write(tableAlias.getQualifiedNameDelimited(platform));
getWriter().write(".");
getWriter().write(field.getNameDelimited(platform));
} else {
getWriter().write(field.getNameDelimited(platform));
}
} catch (IOException exception) {
throw ValidationException.fileError(exception);
}
}
public void printParameter(ParameterExpression expression) {
try {
getCall().appendTranslationParameter(getWriter(), expression, getPlatform(), getTranslationRow());
} catch (IOException exception) {
throw ValidationException.fileError(exception);
}
}
public void printParameter(DatabaseField field) {
getCall().appendTranslation(getWriter(), field);
}
public void printPrimitive(Object value, Boolean canBind) {
if (value instanceof Collection) {
printValuelist((Collection)value, canBind);
return;
}
session.getPlatform().appendLiteralToCall(getCall(), getWriter(), value, canBind);
}
public void printNull(ConstantExpression nullValueExpression) {
if(session.getPlatform().shouldBindLiterals()) {
DatabaseField field = null;
Expression localBase = nullValueExpression.getLocalBase();
if(localBase != null && (localBase.isFieldExpression() || localBase.isQueryKeyExpression())) {
field = ((DataExpression)localBase).getField();
}
session.getPlatform().appendLiteralToCall(getCall(), getWriter(), field, nullValueExpression.canBind());
} else {
session.getPlatform().appendLiteralToCall(getCall(), getWriter(), null, nullValueExpression.canBind());
}
}
public void printString(String value) {
try {
getWriter().write(value);
} catch (IOException exception) {
throw ValidationException.fileError(exception);
}
}
public void printValuelist(Collection values, Boolean canBind) {
try {
getWriter().write("(");
if (values == null || values.isEmpty()) {
getWriter().write(NULL_STRING);
} else {
Iterator valuesEnum = values.iterator();
while (valuesEnum.hasNext()) {
Object value = valuesEnum.next();
// Support nested arrays for IN.
if (value instanceof Collection) {
printValuelist((Collection) value, canBind);
} else if (value instanceof Expression) {
((Expression) value).printSQL(this);
} else {
session.getPlatform().appendLiteralToCall(getCall(), getWriter(), value, canBind);
}
if (valuesEnum.hasNext()) {
getWriter().write(", ");
}
}
}
getWriter().write(")");
} catch (IOException exception) {
throw ValidationException.fileError(exception);
}
}
/*
* Same as printValuelist, but allows for collections containing expressions recursively
*/
public void printList(Collection values, Boolean canBind) {
try {
getWriter().write("(");
if (values == null || values.isEmpty()) {
getWriter().write(NULL_STRING);
} else {
Iterator valuesEnum = values.iterator();
while (valuesEnum.hasNext()) {
Object value = valuesEnum.next();
if (value instanceof Expression) {
((Expression) value).printSQL(this);
} else {
session.getPlatform().appendLiteralToCall(getCall(), getWriter(), value, canBind);
}
if (valuesEnum.hasNext()) {
getWriter().write(", ");
}
}
}
getWriter().write(")");
} catch (IOException exception) {
throw ValidationException.fileError(exception);
}
}
/**
* If a distinct has been set the DISTINCT clause will be printed.
* This is required for batch reading.
*/
public boolean requiresDistinct() {
return requiresDistinct;
}
protected void setCall(SQLCall call) {
this.call = call;
}
/**
* INTERNAL:
* Used in figuring out when to print a comma in the select clause
*/
public void setIsFirstElementPrinted(boolean isFirstElementPrinted) {
this.isFirstElementPrinted = isFirstElementPrinted;
}
/**
* If a distinct has been set the DISTINCT clause will be printed.
* This is required for batch reading.
*/
public void setRequiresDistinct(boolean requiresDistinct) {
this.requiresDistinct = requiresDistinct;
}
protected void setSession(AbstractSession theSession) {
session = theSession;
}
protected void setShouldPrintQualifiedNames(boolean shouldPrintQualifiedNames) {
this.shouldPrintQualifiedNames = shouldPrintQualifiedNames;
}
/**
* INTERNAL:
* Set the row for translation
*/
protected void setTranslationRow(AbstractRecord theRow) {
translationRow = theRow;
}
public void setWriter(Writer writer) {
this.writer = writer;
}
public boolean shouldPrintParameterValues() {
return getTranslationRow() != null;
}
protected boolean shouldPrintQualifiedNames() {
return shouldPrintQualifiedNames;
}
/**
* Translate an expression i.e. call the appropriate
* translation method for the expression based on its
* type. The translation method is then responsible
* for translating the subexpressions.
*/
protected void translateExpression(Expression theExpression) {
theExpression.printSQL(this);
}
}