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/*
* Copyright (c) 1998, 2019 Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1998, 2019 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
// 09/14/2011-2.3.1 Guy Pelletier
// - 357533: Allow DDL queries to execute even when Multitenant entities are part of the PU
// 02/19/2015 - Rick Curtis
// - 458877 : Add national character support
// 02/24/2016-2.6.0 Rick Curtis
// - 460740: Fix pessimistic locking with setFirst/Max results on DB2
// 03/13/2015 - Jody Grassel
// - 462103 : SQL for Stored Procedure named parameter with DB2 generated with incorrect marker
// 04/15/2016 - Dalia Abo Sheasha
// - 491824: Setting lock timeout to 0 issues a NOWAIT causing an error in DB2
// 08/22/2017 - Will Dazey
// - 521037: DB2 default schema is doubled for sequence queries
// 12/06/2018 - Will Dazey
// - 542491: Add new 'eclipselink.jdbc.force-bind-parameters' property to force enable binding
package org.eclipse.persistence.platform.database;
import java.io.*;
import java.sql.*;
import java.util.*;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.expressions.*;
import org.eclipse.persistence.internal.helper.*;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.AbstractSession;
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.ParameterExpression;
import org.eclipse.persistence.internal.expressions.SQLSelectStatement;
import org.eclipse.persistence.queries.*;
import org.eclipse.persistence.tools.schemaframework.FieldDefinition;
/**
*
* Purpose: Provides DB2 specific behavior.
*
* Responsibilities:
*
* - Support for schema creation.
*
- Native SQL for byte[], Date, Time, {@literal &} Timestamp.
*
- Support for table qualified names.
*
- Support for stored procedures.
*
- Support for temp tables.
*
- Support for casting.
*
- Support for database functions.
*
- Support for identity sequencing.
*
- Support for SEQUENCE sequencing.
*
*
* @since TOPLink/Java 1.0
*/
public class DB2Platform extends org.eclipse.persistence.platform.database.DatabasePlatform {
public DB2Platform() {
super();
//com.ibm.db2.jcc.DB2Types.CURSOR
this.cursorCode = -100008;
this.shouldBindLiterals = false;
this.pingSQL = "VALUES(1)";
}
@Override
public void initializeConnectionData(Connection connection) throws SQLException {
// DB2 database doesn't support NVARCHAR column types and as such doesn't support calling
// get/setNString() on the driver.
this.driverSupportsNationalCharacterVarying = false;
}
/**
* INTERNAL:
* Append a byte[] in native DB@ format BLOB(hexString) if usesNativeSQL(),
* otherwise use ODBC format from DatabasePLatform.
*/
@Override
protected void appendByteArray(byte[] bytes, Writer writer) throws IOException {
if (usesNativeSQL()) {
writer.write("BLOB(x'");
Helper.writeHexString(bytes, writer);
writer.write("')");
} else {
super.appendByteArray(bytes, writer);
}
}
/**
* INTERNAL:
* Appends the Date in native format if usesNativeSQL() otherwise use ODBC
* format from DatabasePlatform. Native format: 'mm/dd/yyyy'
*/
@Override
protected void appendDate(java.sql.Date date, Writer writer) throws IOException {
if (usesNativeSQL()) {
appendDB2Date(date, writer);
} else {
super.appendDate(date, writer);
}
}
/**
* INTERNAL:
* Write a timestamp in DB2 specific format (mm/dd/yyyy).
*/
protected void appendDB2Date(java.sql.Date date, Writer writer) throws IOException {
writer.write("'");
// PERF: Avoid deprecated get methods, that are now very inefficient and
// used from toString.
Calendar calendar = Helper.allocateCalendar();
calendar.setTime(date);
if ((calendar.get(Calendar.MONTH) + 1) < 10) {
writer.write('0');
}
writer.write(Integer.toString(calendar.get(Calendar.MONTH) + 1));
writer.write('/');
if (calendar.get(Calendar.DATE) < 10) {
writer.write('0');
}
writer.write(Integer.toString(calendar.get(Calendar.DATE)));
writer.write('/');
writer.write(Integer.toString(calendar.get(Calendar.YEAR)));
writer.write("'");
Helper.releaseCalendar(calendar);
}
/**
* INTERNAL:
* Write a timestamp in DB2 specific format (yyyy-mm-dd-hh.mm.ss.ffffff).
*/
protected void appendDB2Timestamp(java.sql.Timestamp timestamp, Writer writer) throws IOException {
// PERF: Avoid deprecated get methods, that are now very inefficient and
// used from toString.
Calendar calendar = Helper.allocateCalendar();
calendar.setTime(timestamp);
writer.write(Helper.printDate(calendar));
writer.write('-');
if (calendar.get(Calendar.HOUR_OF_DAY) < 10) {
writer.write('0');
}
writer.write(Integer.toString(calendar.get(Calendar.HOUR_OF_DAY)));
writer.write('.');
if (calendar.get(Calendar.MINUTE) < 10) {
writer.write('0');
}
writer.write(Integer.toString(calendar.get(Calendar.MINUTE)));
writer.write('.');
if (calendar.get(Calendar.SECOND) < 10) {
writer.write('0');
}
writer.write(Integer.toString(calendar.get(Calendar.SECOND)));
writer.write('.');
Helper.releaseCalendar(calendar);
// Must truncate the nanos to six decimal places,
// it is actually a complex algorithm...
String nanoString = Integer.toString(timestamp.getNanos());
int numberOfZeros = 0;
for (int num = Math.min(9 - nanoString.length(), 6); num > 0; num--) {
writer.write('0');
numberOfZeros++;
}
if ((nanoString.length() + numberOfZeros) > 6) {
nanoString = nanoString.substring(0, (6 - numberOfZeros));
}
writer.write(nanoString);
}
/**
* Write a timestamp in DB2 specific format (yyyy-mm-dd-hh.mm.ss.ffffff).
*/
protected void appendDB2Calendar(Calendar calendar, Writer writer) throws IOException {
int hour;
int minute;
int second;
if (!Helper.getDefaultTimeZone().equals(calendar.getTimeZone())) {
// Must convert the calendar to the local timezone if different, as
// dates have no timezone (always local).
Calendar localCalendar = Helper.allocateCalendar();
localCalendar.setTimeInMillis(calendar.getTimeInMillis());
hour = calendar.get(Calendar.HOUR_OF_DAY);
minute = calendar.get(Calendar.MINUTE);
second = calendar.get(Calendar.SECOND);
Helper.releaseCalendar(localCalendar);
} else {
hour = calendar.get(Calendar.HOUR_OF_DAY);
minute = calendar.get(Calendar.MINUTE);
second = calendar.get(Calendar.SECOND);
}
writer.write(Helper.printDate(calendar));
writer.write('-');
if (hour < 10) {
writer.write('0');
}
writer.write(Integer.toString(hour));
writer.write('.');
if (minute < 10) {
writer.write('0');
}
writer.write(Integer.toString(minute));
writer.write('.');
if (second < 10) {
writer.write('0');
}
writer.write(Integer.toString(second));
writer.write('.');
// Must truncate the nanos to six decimal places,
// it is actually a complex algorithm...
String millisString = Integer.toString(calendar.get(Calendar.MILLISECOND));
int numberOfZeros = 0;
for (int num = Math.min(3 - millisString.length(), 3); num > 0; num--) {
writer.write('0');
numberOfZeros++;
}
if ((millisString.length() + numberOfZeros) > 3) {
millisString = millisString.substring(0, (3 - numberOfZeros));
}
writer.write(millisString);
}
/**
* INTERNAL:
* Append the Time in Native format if usesNativeSQL() otherwise use ODBC
* format from DAtabasePlatform. Native Format: 'hh:mm:ss'
*/
@Override
protected void appendTime(java.sql.Time time, Writer writer) throws IOException {
if (usesNativeSQL()) {
writer.write("'");
writer.write(Helper.printTime(time));
writer.write("'");
} else {
super.appendTime(time, writer);
}
}
/**
* INTERNAL:
* Append the Timestamp in native format if usesNativeSQL() is true
* otherwise use ODBC format from DatabasePlatform. Native format:
* 'YYYY-MM-DD-hh.mm.ss.SSSSSS'
*/
@Override
protected void appendTimestamp(java.sql.Timestamp timestamp, Writer writer) throws IOException {
if (usesNativeSQL()) {
writer.write("'");
appendDB2Timestamp(timestamp, writer);
writer.write("'");
} else {
super.appendTimestamp(timestamp, writer);
}
}
/**
* INTERNAL:
* Append the Timestamp in native format if usesNativeSQL() is true
* otherwise use ODBC format from DatabasePlatform. Native format:
* 'YYYY-MM-DD-hh.mm.ss.SSSSSS'
*/
@Override
protected void appendCalendar(Calendar calendar, Writer writer) throws IOException {
if (usesNativeSQL()) {
writer.write("'");
appendDB2Calendar(calendar, writer);
writer.write("'");
} else {
super.appendCalendar(calendar, writer);
}
}
@Override
protected Hashtable buildFieldTypes() {
Hashtable fieldTypeMapping = new Hashtable();
fieldTypeMapping.put(Boolean.class, new FieldTypeDefinition("SMALLINT DEFAULT 0", false));
fieldTypeMapping.put(Integer.class, new FieldTypeDefinition("INTEGER", false));
fieldTypeMapping.put(Long.class, new FieldTypeDefinition("BIGINT", false));
fieldTypeMapping.put(Float.class, new FieldTypeDefinition("FLOAT", false));
fieldTypeMapping.put(Double.class, new FieldTypeDefinition("FLOAT", 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("BIGINT", false));
fieldTypeMapping.put(java.math.BigDecimal.class, new FieldTypeDefinition("DECIMAL", 15));
fieldTypeMapping.put(Number.class, new FieldTypeDefinition("DECIMAL", 15));
if(getUseNationalCharacterVaryingTypeForString()){
fieldTypeMapping.put(String.class, new FieldTypeDefinition("VARCHAR", DEFAULT_VARCHAR_SIZE, "FOR MIXED DATA"));
}else {
fieldTypeMapping.put(String.class, new FieldTypeDefinition("VARCHAR", DEFAULT_VARCHAR_SIZE));
}
fieldTypeMapping.put(Character.class, new FieldTypeDefinition("CHAR", 1));
fieldTypeMapping.put(Byte[].class, new FieldTypeDefinition("BLOB", 64000));
fieldTypeMapping.put(Character[].class, new FieldTypeDefinition("CLOB", 64000));
fieldTypeMapping.put(byte[].class, new FieldTypeDefinition("BLOB", 64000));
fieldTypeMapping.put(char[].class, new FieldTypeDefinition("CLOB", 64000));
fieldTypeMapping.put(java.sql.Blob.class, new FieldTypeDefinition("BLOB", 64000));
fieldTypeMapping.put(java.sql.Clob.class, new FieldTypeDefinition("CLOB", 64000));
fieldTypeMapping.put(java.sql.Date.class, new FieldTypeDefinition("DATE", false));
fieldTypeMapping.put(java.sql.Time.class, new FieldTypeDefinition("TIME", false));
fieldTypeMapping.put(java.sql.Timestamp.class, new FieldTypeDefinition("TIMESTAMP", false));
return fieldTypeMapping;
}
/**
* INTERNAL: returns the maximum number of characters that can be used in a
* field name on this platform.
*/
@Override
public int getMaxFieldNameSize() {
return 128;
}
/**
* INTERNAL: returns the maximum number of characters that can be used in a
* foreign key name on this platform.
*/
@Override
public int getMaxForeignKeyNameSize() {
return 18;
}
/**
* INTERNAL:
* returns the maximum number of characters that can be used in a unique key
* name on this platform.
*/
@Override
public int getMaxUniqueKeyNameSize() {
return 18;
}
/**
* INTERNAL:
* Return the catalog information through using the native SQL catalog
* selects. This is required because many JDBC driver do not support
* meta-data. Wildcards can be passed as arguments.
* This is currently not used.
*/
public Vector getNativeTableInfo(String table, String creator, AbstractSession session) {
String query = "SELECT * FROM SYSIBM.SYSTABLES WHERE TBCREATOR NOT IN ('SYS', 'SYSTEM')";
if (table != null) {
if (table.indexOf('%') != -1) {
query = query + " AND TBNAME LIKE " + table;
} else {
query = query + " AND TBNAME = " + table;
}
}
if (creator != null) {
if (creator.indexOf('%') != -1) {
query = query + " AND TBCREATOR LIKE " + creator;
} else {
query = query + " AND TBCREATOR = " + creator;
}
}
return session.executeSelectingCall(new org.eclipse.persistence.queries.SQLCall(query));
}
/**
* INTERNAL:
* Used for sp calls.
*/
@Override
public String getProcedureCallHeader() {
return "CALL ";
}
/**
* INTERNAL:
* Used for pessimistic locking in DB2.
* Without the "WITH RS" the lock is not held.
*/
// public String getSelectForUpdateString() { return " FOR UPDATE"; }
@Override
public String getSelectForUpdateString() {
return " FOR READ ONLY WITH RS USE AND KEEP UPDATE LOCKS";
//return " FOR READ ONLY WITH RR";
//return " FOR READ ONLY WITH RS";
//return " FOR UPDATE WITH RS";
}
/**
* INTERNAL:
* Used for stored procedure defs.
*/
@Override
public String getProcedureEndString() {
return "END";
}
/**
* Used for stored procedure defs.
*/
@Override
public String getProcedureBeginString() {
return "BEGIN";
}
/**
* INTERNAL:
* Used for stored procedure defs.
*/
@Override
public String getProcedureAsString() {
return "";
}
/**
* Obtain the platform specific argument string
*/
@Override
public String getProcedureArgument(String name, Object parameter, Integer parameterType, StoredProcedureCall call, AbstractSession session) {
if (name != null && shouldPrintStoredProcedureArgumentNameInCall()) {
return getProcedureArgumentString() + name + " => " + "?";
}
return "?";
}
/**
* INTERNAL:
* This is required in the construction of the stored procedures with output
* parameters.
*/
@Override
public boolean shouldPrintOutputTokenAtStart() {
return true;
}
/**
* INTERNAL:
* This method returns the query to select the timestamp from the server for
* DB2.
*/
@Override
public ValueReadQuery getTimestampQuery() {
if (timestampQuery == null) {
timestampQuery = new ValueReadQuery();
timestampQuery.setSQLString("SELECT CURRENT TIMESTAMP FROM SYSIBM.SYSDUMMY1");
timestampQuery.setAllowNativeSQLQuery(true);
}
return timestampQuery;
}
/**
* INTERNAL:
* Initialize any platform-specific operators
*/
@Override
protected void initializePlatformOperators() {
super.initializePlatformOperators();
addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.ToUpperCase, "UCASE"));
addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.ToLowerCase, "LCASE"));
addOperator(concatOperator());
addOperator(ExpressionOperator.simpleTwoArgumentFunction(ExpressionOperator.Instring, "Locate"));
// CR#2811076 some missing DB2 functions added.
addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.ToNumber, "DECIMAL"));
addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.ToChar, "CHAR"));
addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.DateToString, "CHAR"));
addOperator(ExpressionOperator.simpleFunction(ExpressionOperator.ToDate, "DATE"));
addOperator(ltrim2Operator());
addOperator(rtrim2Operator());
}
@Override
public boolean isDB2() {
return true;
}
/**
* INTERNAL:
* Builds a table of maximum numeric values keyed on java class. This is
* used for type testing but might also be useful to end users attempting to
* sanitize values.
*
* NOTE: BigInteger {@literal &} BigDecimal maximums are dependent upon their
* precision {@literal &} Scale
*/
@Override
public Hashtable maximumNumericValues() {
Hashtable values = new Hashtable();
values.put(Integer.class, Integer.valueOf(Integer.MAX_VALUE));
values.put(Long.class, Long.valueOf(Integer.MAX_VALUE));
values.put(Float.class, Float.valueOf(123456789));
values.put(Double.class, Double.valueOf(Float.MAX_VALUE));
values.put(Short.class, Short.valueOf(Short.MAX_VALUE));
values.put(Byte.class, Byte.valueOf(Byte.MAX_VALUE));
values.put(java.math.BigInteger.class, new java.math.BigInteger("999999999999999"));
values.put(java.math.BigDecimal.class, new java.math.BigDecimal("0.999999999999999"));
return values;
}
/**
* INTERNAL:
* Builds a table of minimum numeric values keyed on java class. This is
* used for type testing but might also be useful to end users attempting to
* sanitize values.
*
* NOTE: BigInteger {@literal &} BigDecimal minimums are dependent upon their
* precision {@literal &} Scale
*/
@Override
public Hashtable minimumNumericValues() {
Hashtable values = new Hashtable();
values.put(Integer.class, Integer.valueOf(Integer.MIN_VALUE));
values.put(Long.class, Long.valueOf(Integer.MIN_VALUE));
values.put(Float.class, Float.valueOf(-123456789));
values.put(Double.class, Double.valueOf(Float.MIN_VALUE));
values.put(Short.class, Short.valueOf(Short.MIN_VALUE));
values.put(Byte.class, Byte.valueOf(Byte.MIN_VALUE));
values.put(java.math.BigInteger.class, new java.math.BigInteger("-999999999999999"));
values.put(java.math.BigDecimal.class, new java.math.BigDecimal("-0.999999999999999"));
return values;
}
/**
* INTERNAL:
* Allow for the platform to ignore exceptions. This is required for DB2
* which throws no-data modified as an exception.
*/
@Override
public boolean shouldIgnoreException(SQLException exception) {
if (exception.getMessage().equals("No data found") || exception.getMessage().equals("No row was found for FETCH, UPDATE or DELETE; or the result of a query is an empty table")
|| (exception.getErrorCode() == 100)) {
return true;
}
return super.shouldIgnoreException(exception);
}
/**
* INTERNAL:
* JDBC defines and outer join syntax, many drivers do not support this. So
* we normally avoid it.
*/
@Override
public boolean shouldUseJDBCOuterJoinSyntax() {
return false;
}
/**
* INTERNAL:
* The Concat operator is of the form .... VARCHAR ( ||
* )
*/
private ExpressionOperator concatOperator() {
ExpressionOperator exOperator = new ExpressionOperator();
exOperator.setType(ExpressionOperator.FunctionOperator);
exOperator.setSelector(ExpressionOperator.Concat);
Vector v = new Vector(5);
v.add("VARCHAR(");
v.add(" || ");
v.add(")");
exOperator.printsAs(v);
exOperator.bePrefix();
exOperator.setNodeClass(ClassConstants.FunctionExpression_Class);
return exOperator;
}
/**
* INTERNAL:
* The 2 arg LTRIM operator is of the form .... TRIM (LEADING, FROM )
*/
private ExpressionOperator ltrim2Operator() {
ExpressionOperator operator = new ExpressionOperator();
operator.setType(ExpressionOperator.FunctionOperator);
operator.setSelector(ExpressionOperator.LeftTrim2);
Vector v = new Vector(5);
v.add("TRIM(LEADING ");
v.add(" FROM ");
v.add(")");
operator.printsAs(v);
operator.bePrefix();
int[] argumentIndices = new int[2];
argumentIndices[0] = 1;
argumentIndices[1] = 0;
operator.setArgumentIndices(argumentIndices);
operator.setNodeClass(ClassConstants.FunctionExpression_Class);
operator.setIsBindingSupported(false);
return operator;
}
/**
* INTERNAL:
* The 2 arg RTRIM operator is of the form .... TRIM (TRAILING, FROM )
*/
private ExpressionOperator rtrim2Operator() {
ExpressionOperator operator = new ExpressionOperator();
operator.setType(ExpressionOperator.FunctionOperator);
operator.setSelector(ExpressionOperator.RightTrim2);
Vector v = new Vector(5);
v.add("TRIM(TRAILING ");
v.add(" FROM ");
v.add(")");
operator.printsAs(v);
operator.bePrefix();
int[] argumentIndices = new int[2];
argumentIndices[0] = 1;
argumentIndices[1] = 0;
operator.setArgumentIndices(argumentIndices);
operator.setNodeClass(ClassConstants.FunctionExpression_Class);
operator.setIsBindingSupported(false);
return operator;
}
/**
* INTERNAL: Build the identity query for native sequencing.
*/
@Override
public ValueReadQuery buildSelectQueryForIdentity() {
ValueReadQuery selectQuery = new ValueReadQuery();
StringWriter writer = new StringWriter();
writer.write("SELECT IDENTITY_VAL_LOCAL() FROM SYSIBM.SYSDUMMY1");
selectQuery.setSQLString(writer.toString());
return selectQuery;
}
/**
* INTERNAL: Append the receiver's field 'identity' constraint clause to a
* writer.
* Used by table creation with sequencing.
*/
@Override
public void printFieldIdentityClause(Writer writer) throws ValidationException {
try {
writer.write(" GENERATED ALWAYS AS IDENTITY");
} catch (IOException ioException) {
throw ValidationException.fileError(ioException);
}
}
@Override
protected void printFieldTypeSize(Writer writer, FieldDefinition field, FieldTypeDefinition ftd) throws IOException {
super.printFieldTypeSize(writer, field, ftd);
String suffix = ftd.getTypesuffix();
if (suffix != null) {
writer.append(" " + suffix);
}
}
/**
* INTERNAL: Indicates whether the platform supports identity. DB2 does
* through AS IDENTITY field types.
* This is used by sequencing.
*/
@Override
public boolean supportsIdentity() {
return true;
}
/**
* INTERNAL: DB2 supports temp tables.
* This is used by UpdateAllQuerys.
*/
@Override
public boolean supportsGlobalTempTables() {
return true;
}
/**
* INTERNAL: DB2 temp table syntax.
* This is used by UpdateAllQuerys.
*/
@Override
protected String getCreateTempTableSqlPrefix() {
return "DECLARE GLOBAL TEMPORARY TABLE ";
}
/**
* INTERNAL: DB2 temp table syntax.
* This is used by UpdateAllQuerys.
*/
@Override
public DatabaseTable getTempTableForTable(DatabaseTable table) {
DatabaseTable tempTable = super.getTempTableForTable(table);
tempTable.setTableQualifier("session");
return tempTable;
}
/**
* INTERNAL: DB2 temp table syntax.
* This is used by UpdateAllQuerys.
*/
@Override
protected String getCreateTempTableSqlSuffix() {
return " ON COMMIT DELETE ROWS NOT LOGGED";
}
/**
* INTERNAL: DB2 allows LIKE to be used to create temp tables, which avoids having to know the types.
* This is used by UpdateAllQuerys.
*/
@Override
protected String getCreateTempTableSqlBodyForTable(DatabaseTable table) {
return " LIKE " + table.getQualifiedNameDelimited(this);
}
/**
* INTERNAL: DB2 does not support NOWAIT.
*/
@Override
public String getNoWaitString() {
return "";
}
/**
* INTERNAL: DB2 has issues with binding with temp table queries.
* This is used by UpdateAllQuerys.
*/
@Override
public boolean dontBindUpdateAllQueryUsingTempTables() {
return true;
}
/**
* INTERNAL: DB2 does not allow NULL in select clause.
* This is used by UpdateAllQuerys.
*/
@Override
public boolean isNullAllowedInSelectClause() {
return false;
}
/**
* INTERNAL
* DB2 has some issues with using parameters on certain functions and relations.
* This allows statements to disable binding only in these cases.
* If users set casting on, then casting is used instead of dynamic SQL.
*/
@Override
public boolean isDynamicSQLRequiredForFunctions() {
if(shouldForceBindAllParameters()) {
return false;
}
return !isCastRequired();
}
/**
* INTERNAL:
* DB2 requires casting on certain operations, such as the CONCAT function,
* and parameterized queries of the form, ":param = :param". This method
* will write CAST operation to parameters if the type is known.
* This is not used by default, only if isCastRequired is set to true,
* by default dynamic SQL is used to avoid the issue in only the required cases.
*/
@Override
public void writeParameterMarker(Writer writer, ParameterExpression parameter, AbstractRecord record, DatabaseCall call) throws IOException {
String paramaterMarker = "?";
Object type = parameter.getType();
// Update-all query requires casting of null parameter values in select into.
if ((type != null) && (this.isCastRequired || ((call.getQuery() != null) && call.getQuery().isUpdateAllQuery()))) {
BasicTypeHelperImpl typeHelper = BasicTypeHelperImpl.getInstance();
String castType = null;
if (typeHelper.isBooleanType(type) || typeHelper.isByteType(type) || typeHelper.isShortType(type)) {
castType = "SMALLINT";
} else if (typeHelper.isIntType(type)) {
castType = "INTEGER";
} else if (typeHelper.isLongType(type)) {
castType = "BIGINT";
} else if (typeHelper.isFloatType(type)) {
castType = "REAL";
} else if (typeHelper.isDoubleType(type)) {
castType = "DOUBLE";
} else if (typeHelper.isStringType(type)) {
castType = "VARCHAR(" + getCastSizeForVarcharParameter() + ")";
}
if (castType != null) {
paramaterMarker = "CAST (? AS " + castType + " )";
}
}
writer.write(paramaterMarker);
}
/**
* INTERNAL:
* DB2 does not seem to allow FOR UPDATE on queries with multiple tables.
* This is only used by testing to exclude these tests.
*/
@Override
public boolean supportsLockingQueriesWithMultipleTables() {
return false;
}
/**
* INTERNAL: DB2 added SEQUENCE support as of (I believe) v8.
*/
@Override
public ValueReadQuery buildSelectQueryForSequenceObject(String qualifiedSeqName, Integer size) {
return new ValueReadQuery("VALUES(NEXT VALUE FOR " + qualifiedSeqName + ")");
}
/**
* INTERNAL: DB2 added SEQUENCE support as of (I believe) v8.
*/
@Override
public boolean supportsSequenceObjects() {
return true;
}
/**
* INTERNAL: DB2 added SEQUENCE support as of (I believe) v8.
*/
@Override
public boolean isAlterSequenceObjectSupported() {
return true;
}
@Override
public boolean shouldPrintForUpdateClause() {
return false;
}
/**
* INTERNAL:
* Print the SQL representation of the statement on a stream, storing the fields
* in the DatabaseCall. This implementation works MaxRows and FirstResult into the SQL using
* DB2's ROWNUMBER() OVER() to filter values if shouldUseRownumFiltering is true.
*/
@Override
public void printSQLSelectStatement(DatabaseCall call, ExpressionSQLPrinter printer, SQLSelectStatement statement){
int max = 0;
int firstRow = 0;
if (statement.getQuery()!=null){
max = statement.getQuery().getMaxRows();
firstRow = statement.getQuery().getFirstResult();
}
if ( !(this.shouldUseRownumFiltering()) || ( !(max>0) && !(firstRow>0) ) ){
super.printSQLSelectStatement(call, printer, statement);
statement.appendForUpdateClause(printer);
return;
} else if ( max > 0 ){
statement.setUseUniqueFieldAliases(true);
printer.printString("SELECT * FROM (SELECT * FROM (SELECT ");
printer.printString("EL_TEMP.*, ROWNUMBER() OVER() AS EL_ROWNM FROM (");
call.setFields(statement.printSQL(printer));
printer.printString(") AS EL_TEMP) AS EL_TEMP2 WHERE EL_ROWNM <= ");
printer.printParameter(DatabaseCall.MAXROW_FIELD);
printer.printString(") AS EL_TEMP3 WHERE EL_ROWNM > ");
printer.printParameter(DatabaseCall.FIRSTRESULT_FIELD);
// If we have a ForUpdate clause, it must be on the outermost query
statement.appendForUpdateClause(printer);
} else {// firstRow>0
statement.setUseUniqueFieldAliases(true);
printer.printString("SELECT * FROM (SELECT EL_TEMP.*, ROWNUMBER() OVER() AS EL_ROWNM FROM (");
call.setFields(statement.printSQL(printer));
printer.printString(") AS EL_TEMP) AS EL_TEMP2 WHERE EL_ROWNM > ");
printer.printParameter(DatabaseCall.FIRSTRESULT_FIELD);
statement.appendForUpdateClause(printer);
}
call.setIgnoreFirstRowSetting(true);
call.setIgnoreMaxResultsSetting(true);
}
}