/*******************************************************************************
* Copyright (c) 1998, 2009 Oracle. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Mike Keith
*
* Patterned after:
* org.eclipse.persistence.platform.database.DB2MainframePlatform
******************************************************************************/
package org.eclipse.persistence.platform.database;
import java.io.*;
import java.util.*;
import org.eclipse.persistence.internal.databaseaccess.DatabaseCall;
import org.eclipse.persistence.internal.databaseaccess.FieldTypeDefinition;
import org.eclipse.persistence.internal.expressions.ExpressionSQLPrinter;
import org.eclipse.persistence.internal.expressions.SQLSelectStatement;
import org.eclipse.persistence.internal.helper.ClassConstants;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.helper.DatabaseTable;
import org.eclipse.persistence.queries.ValueReadQuery;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.expressions.ExpressionOperator;
public class H2Platform extends DatabasePlatform {
private static final long serialVersionUID = -2935483687958482934L;
public H2Platform() {
super();
setPingSQL("SELECT 1");
}
/**
* Print the pagination SQL using H2 syntax " LIMIT <max> OFFSET <first>".
*/
@Override
public void printSQLSelectStatement(DatabaseCall call, ExpressionSQLPrinter printer, SQLSelectStatement statement) {
int max = 0;
if (statement.getQuery() != null) {
max = statement.getQuery().getMaxRows();
}
if (max <= 0 || !(this.shouldUseRownumFiltering())) {
super.printSQLSelectStatement(call, printer, statement);
return;
}
statement.setUseUniqueFieldAliases(true);
call.setFields(statement.printSQL(printer));
printer.printString(" LIMIT ");
printer.printParameter(DatabaseCall.MAXROW_FIELD);
printer.printString(" OFFSET ");
printer.printParameter(DatabaseCall.FIRSTRESULT_FIELD);
call.setIgnoreFirstRowMaxResultsSettings(true);
}
/**
* INTERNAL:
* Use the JDBC maxResults and firstResultIndex setting to compute a value to use when
* limiting the results of a query in SQL. These limits tend to be used in two ways.
*
* 1. MaxRows is the index of the last row to be returned (like JDBC maxResults)
* 2. MaxRows is the number of rows to be returned
*
* H2 uses case #2 and therefore the maxResults has to be altered based on the firstResultIndex.
*/
@Override
public int computeMaxRowsForSQL(int firstResultIndex, int maxResults){
return maxResults - ((firstResultIndex >= 0) ? firstResultIndex : 0);
}
@Override
protected Hashtable buildFieldTypes() {
Hashtable fieldTypeMapping = super.buildFieldTypes();
fieldTypeMapping.put(Boolean.class, new FieldTypeDefinition("BOOLEAN", false));
fieldTypeMapping.put(Integer.class, new FieldTypeDefinition("INTEGER", false));
fieldTypeMapping.put(Long.class, new FieldTypeDefinition("BIGINT", false));
fieldTypeMapping.put(Float.class, new FieldTypeDefinition("DOUBLE", false));
fieldTypeMapping.put(Double.class, new FieldTypeDefinition("DOUBLE", false));
fieldTypeMapping.put(Short.class, new FieldTypeDefinition("SMALLINT", false));
fieldTypeMapping.put(Byte.class, new FieldTypeDefinition("SMALLINT", false));
fieldTypeMapping.put(java.math.BigInteger.class, new FieldTypeDefinition("NUMERIC", 38));
fieldTypeMapping.put(java.math.BigDecimal.class, new FieldTypeDefinition("NUMERIC", 38).setLimits(38, -19, 19));
fieldTypeMapping.put(Number.class, new FieldTypeDefinition("NUMERIC", 38).setLimits(38, -19, 19));
fieldTypeMapping.put(Byte[].class, new FieldTypeDefinition("LONGVARBINARY", false));
fieldTypeMapping.put(Character[].class, new FieldTypeDefinition("LONGVARCHAR", false));
fieldTypeMapping.put(byte[].class, new FieldTypeDefinition("LONGVARBINARY", false));
fieldTypeMapping.put(char[].class, new FieldTypeDefinition("LONGVARCHAR", false));
fieldTypeMapping.put(java.sql.Blob.class, new FieldTypeDefinition("BLOB", false));
fieldTypeMapping.put(java.sql.Clob.class, new FieldTypeDefinition("CLOB", false));
fieldTypeMapping.put(java.sql.Date.class, new FieldTypeDefinition("DATE", false));
fieldTypeMapping.put(java.sql.Timestamp.class, new FieldTypeDefinition("TIMESTAMP", false));
fieldTypeMapping.put(java.sql.Time.class, new FieldTypeDefinition("TIME", false));
fieldTypeMapping.put(java.util.Calendar.class, new FieldTypeDefinition("TIMESTAMP", false));
fieldTypeMapping.put(java.util.Date.class, new FieldTypeDefinition("TIMESTAMP", false));
return fieldTypeMapping;
}
@Override
public boolean isAlterSequenceObjectSupported() {
return true;
}
/**
* INTERNAL
* H2 has some issues with using parameters on certain functions and relations.
* This allows statements to disable binding only in these cases.
*/
@Override
public boolean isDynamicSQLRequiredForFunctions() {
return true;
}
@Override
public ValueReadQuery buildSelectQueryForSequenceObject(String seqName, Integer size) {
return new ValueReadQuery(new StringBuilder(20 + seqName.length()).append("CALL NEXT VALUE FOR ").append(seqName).toString());
}
@Override
public boolean supportsIdentity() {
return true;
}
@Override
public boolean supportsSequenceObjects() {
return true;
}
@Override
public ValueReadQuery buildSelectQueryForIdentity() {
return new ValueReadQuery("CALL IDENTITY()");
}
@Override
public void printFieldIdentityClause(Writer writer) throws ValidationException {
try {
writer.append(" IDENTITY");
} catch (IOException e) {
throw ValidationException.logIOError(e);
}
}
@Override
public boolean supportsForeignKeyConstraints() {
return true;
}
@Override
public boolean supportsGlobalTempTables() {
return true;
}
@Override
protected String getCreateTempTableSqlPrefix() {
return "CREATE TEMPORARY TABLE IF NOT EXISTS ";
}
/**
* H2 does not allow using () in the update if only one field.
*/
@Override
public void writeUpdateOriginalFromTempTableSql(Writer writer, DatabaseTable table,
Collection pkFields,
Collection assignedFields) throws IOException
{
writer.write("UPDATE ");
String tableName = table.getQualifiedNameDelimited(this);
writer.write(tableName);
writer.write(" SET ");
if (assignedFields.size() > 1) {
writer.write("(");
}
writeFieldsList(writer, assignedFields, this);
if (assignedFields.size() > 1) {
writer.write(")");
}
writer.write(" = (SELECT ");
writeFieldsList(writer, assignedFields, this);
writer.write(" FROM ");
String tempTableName = getTempTableForTable(table).getQualifiedNameDelimited(this);
writer.write(tempTableName);
writeAutoJoinWhereClause(writer, null, tableName, pkFields, this);
writer.write(") WHERE EXISTS(SELECT ");
writer.write(((DatabaseField)pkFields.iterator().next()).getNameDelimited(this));
writer.write(" FROM ");
writer.write(tempTableName);
writeAutoJoinWhereClause(writer, null, tableName, pkFields, this);
writer.write(")");
}
@Override
public boolean supportsStoredFunctions() {
return true;
}
@Override
public ValueReadQuery getTimestampQuery() {
if (timestampQuery == null) {
timestampQuery = new ValueReadQuery();
timestampQuery.setSQLString("SELECT CURRENT_TIMESTAMP()");
}
return timestampQuery;
}
@Override
protected void initializePlatformOperators() {
super.initializePlatformOperators();
addOperator(ExpressionOperator.simpleMath(ExpressionOperator.Concat, "||"));
addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.Ceil, "CEILING"));
addOperator(ExpressionOperator.simpleTwoArgumentFunction(ExpressionOperator.Nvl, "IFNULL"));
addOperator(toNumberOperator());
addOperator(monthsBetweenOperator());
}
/**
* INTERNAL:
* Use CONVERT function for toNumber.
*/
public static ExpressionOperator toNumberOperator() {
ExpressionOperator exOperator = new ExpressionOperator();
exOperator.setType(ExpressionOperator.FunctionOperator);
exOperator.setSelector(ExpressionOperator.ToNumber);
Vector v = org.eclipse.persistence.internal.helper.NonSynchronizedVector.newInstance(2);
v.addElement("CONVERT(");
v.addElement(",DECIMAL)");
exOperator.printsAs(v);
exOperator.bePrefix();
exOperator.setNodeClass(ClassConstants.FunctionExpression_Class);
return exOperator;
}
/**
* INTERNAL:
* Use MONTH function for MONTH_BETWEEN.
*/
public static ExpressionOperator monthsBetweenOperator() {
ExpressionOperator exOperator = new ExpressionOperator();
exOperator.setType(ExpressionOperator.FunctionOperator);
exOperator.setSelector(ExpressionOperator.MonthsBetween);
Vector v = org.eclipse.persistence.internal.helper.NonSynchronizedVector.newInstance(2);
v.addElement("(MONTH(");
v.addElement(") - MONTH(");
v.addElement("))");
exOperator.printsAs(v);
exOperator.bePrefix();
exOperator.setNodeClass(ClassConstants.FunctionExpression_Class);
return exOperator;
}
@Override
public boolean isH2() {
return true;
}
}