/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.dialect;
import java.sql.CallableStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import org.hibernate.cfg.Environment;
import org.hibernate.dialect.function.AnsiTrimEmulationFunction;
import org.hibernate.dialect.function.AvgWithArgumentCastFunction;
import org.hibernate.dialect.function.NoArgSQLFunction;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.dialect.function.VarArgsSQLFunction;
import org.hibernate.type.StandardBasicTypes;
/**
* An SQL dialect for DB2.
* @author Gavin King
*/
public class DB2Dialect extends Dialect {
public DB2Dialect() {
super();
registerColumnType( Types.BIT, "smallint" );
registerColumnType( Types.BIGINT, "bigint" );
registerColumnType( Types.SMALLINT, "smallint" );
registerColumnType( Types.TINYINT, "smallint" );
registerColumnType( Types.INTEGER, "integer" );
registerColumnType( Types.CHAR, "char(1)" );
registerColumnType( Types.VARCHAR, "varchar($l)" );
registerColumnType( Types.FLOAT, "float" );
registerColumnType( Types.DOUBLE, "double" );
registerColumnType( Types.DATE, "date" );
registerColumnType( Types.TIME, "time" );
registerColumnType( Types.TIMESTAMP, "timestamp" );
registerColumnType( Types.VARBINARY, "varchar($l) for bit data" );
registerColumnType( Types.NUMERIC, "numeric($p,$s)" );
registerColumnType( Types.BLOB, "blob($l)" );
registerColumnType( Types.CLOB, "clob($l)" );
registerColumnType( Types.LONGVARCHAR, "long varchar" );
registerColumnType( Types.LONGVARBINARY, "long varchar for bit data" );
registerFunction( "avg", new AvgWithArgumentCastFunction( "double" ) );
registerFunction("abs", new StandardSQLFunction("abs") );
registerFunction("absval", new StandardSQLFunction("absval") );
registerFunction("sign", new StandardSQLFunction("sign", StandardBasicTypes.INTEGER) );
registerFunction("ceiling", new StandardSQLFunction("ceiling") );
registerFunction("ceil", new StandardSQLFunction("ceil") );
registerFunction("floor", new StandardSQLFunction("floor") );
registerFunction("round", new StandardSQLFunction("round") );
registerFunction("acos", new StandardSQLFunction("acos", StandardBasicTypes.DOUBLE) );
registerFunction("asin", new StandardSQLFunction("asin", StandardBasicTypes.DOUBLE) );
registerFunction("atan", new StandardSQLFunction("atan", StandardBasicTypes.DOUBLE) );
registerFunction("cos", new StandardSQLFunction("cos", StandardBasicTypes.DOUBLE) );
registerFunction("cot", new StandardSQLFunction("cot", StandardBasicTypes.DOUBLE) );
registerFunction("degrees", new StandardSQLFunction("degrees", StandardBasicTypes.DOUBLE) );
registerFunction("exp", new StandardSQLFunction("exp", StandardBasicTypes.DOUBLE) );
registerFunction("float", new StandardSQLFunction("float", StandardBasicTypes.DOUBLE) );
registerFunction("hex", new StandardSQLFunction("hex", StandardBasicTypes.STRING) );
registerFunction("ln", new StandardSQLFunction("ln", StandardBasicTypes.DOUBLE) );
registerFunction("log", new StandardSQLFunction("log", StandardBasicTypes.DOUBLE) );
registerFunction("log10", new StandardSQLFunction("log10", StandardBasicTypes.DOUBLE) );
registerFunction("radians", new StandardSQLFunction("radians", StandardBasicTypes.DOUBLE) );
registerFunction("rand", new NoArgSQLFunction("rand", StandardBasicTypes.DOUBLE) );
registerFunction("sin", new StandardSQLFunction("sin", StandardBasicTypes.DOUBLE) );
registerFunction("soundex", new StandardSQLFunction("soundex", StandardBasicTypes.STRING) );
registerFunction("sqrt", new StandardSQLFunction("sqrt", StandardBasicTypes.DOUBLE) );
registerFunction("stddev", new StandardSQLFunction("stddev", StandardBasicTypes.DOUBLE) );
registerFunction("tan", new StandardSQLFunction("tan", StandardBasicTypes.DOUBLE) );
registerFunction("variance", new StandardSQLFunction("variance", StandardBasicTypes.DOUBLE) );
registerFunction("julian_day", new StandardSQLFunction("julian_day", StandardBasicTypes.INTEGER) );
registerFunction("microsecond", new StandardSQLFunction("microsecond", StandardBasicTypes.INTEGER) );
registerFunction("midnight_seconds", new StandardSQLFunction("midnight_seconds", StandardBasicTypes.INTEGER) );
registerFunction("minute", new StandardSQLFunction("minute", StandardBasicTypes.INTEGER) );
registerFunction("month", new StandardSQLFunction("month", StandardBasicTypes.INTEGER) );
registerFunction("monthname", new StandardSQLFunction("monthname", StandardBasicTypes.STRING) );
registerFunction("quarter", new StandardSQLFunction("quarter", StandardBasicTypes.INTEGER) );
registerFunction("hour", new StandardSQLFunction("hour", StandardBasicTypes.INTEGER) );
registerFunction("second", new StandardSQLFunction("second", StandardBasicTypes.INTEGER) );
registerFunction("current_date", new NoArgSQLFunction("current date", StandardBasicTypes.DATE, false) );
registerFunction("date", new StandardSQLFunction("date", StandardBasicTypes.DATE) );
registerFunction("day", new StandardSQLFunction("day", StandardBasicTypes.INTEGER) );
registerFunction("dayname", new StandardSQLFunction("dayname", StandardBasicTypes.STRING) );
registerFunction("dayofweek", new StandardSQLFunction("dayofweek", StandardBasicTypes.INTEGER) );
registerFunction("dayofweek_iso", new StandardSQLFunction("dayofweek_iso", StandardBasicTypes.INTEGER) );
registerFunction("dayofyear", new StandardSQLFunction("dayofyear", StandardBasicTypes.INTEGER) );
registerFunction("days", new StandardSQLFunction("days", StandardBasicTypes.LONG) );
registerFunction("current_time", new NoArgSQLFunction("current time", StandardBasicTypes.TIME, false) );
registerFunction("time", new StandardSQLFunction("time", StandardBasicTypes.TIME) );
registerFunction("current_timestamp", new NoArgSQLFunction("current timestamp", StandardBasicTypes.TIMESTAMP, false) );
registerFunction("timestamp", new StandardSQLFunction("timestamp", StandardBasicTypes.TIMESTAMP) );
registerFunction("timestamp_iso", new StandardSQLFunction("timestamp_iso", StandardBasicTypes.TIMESTAMP) );
registerFunction("week", new StandardSQLFunction("week", StandardBasicTypes.INTEGER) );
registerFunction("week_iso", new StandardSQLFunction("week_iso", StandardBasicTypes.INTEGER) );
registerFunction("year", new StandardSQLFunction("year", StandardBasicTypes.INTEGER) );
registerFunction("double", new StandardSQLFunction("double", StandardBasicTypes.DOUBLE) );
registerFunction("varchar", new StandardSQLFunction("varchar", StandardBasicTypes.STRING) );
registerFunction("real", new StandardSQLFunction("real", StandardBasicTypes.FLOAT) );
registerFunction("bigint", new StandardSQLFunction("bigint", StandardBasicTypes.LONG) );
registerFunction("char", new StandardSQLFunction("char", StandardBasicTypes.CHARACTER) );
registerFunction("integer", new StandardSQLFunction("integer", StandardBasicTypes.INTEGER) );
registerFunction("smallint", new StandardSQLFunction("smallint", StandardBasicTypes.SHORT) );
registerFunction("digits", new StandardSQLFunction("digits", StandardBasicTypes.STRING) );
registerFunction("chr", new StandardSQLFunction("chr", StandardBasicTypes.CHARACTER) );
registerFunction("upper", new StandardSQLFunction("upper") );
registerFunction("lower", new StandardSQLFunction("lower") );
registerFunction("ucase", new StandardSQLFunction("ucase") );
registerFunction("lcase", new StandardSQLFunction("lcase") );
registerFunction("ltrim", new StandardSQLFunction("ltrim") );
registerFunction("rtrim", new StandardSQLFunction("rtrim") );
registerFunction( "substr", new StandardSQLFunction( "substr", StandardBasicTypes.STRING ) );
registerFunction( "posstr", new StandardSQLFunction( "posstr", StandardBasicTypes.INTEGER ) );
registerFunction( "substring", new StandardSQLFunction( "substr", StandardBasicTypes.STRING ) );
registerFunction( "bit_length", new SQLFunctionTemplate( StandardBasicTypes.INTEGER, "length(?1)*8" ) );
registerFunction( "trim", new AnsiTrimEmulationFunction() );
registerFunction( "concat", new VarArgsSQLFunction(StandardBasicTypes.STRING, "", "||", "") );
registerFunction( "str", new SQLFunctionTemplate( StandardBasicTypes.STRING, "rtrim(char(?1))" ) );
registerKeyword("current");
registerKeyword("date");
registerKeyword("time");
registerKeyword("timestamp");
registerKeyword("fetch");
registerKeyword("first");
registerKeyword("rows");
registerKeyword("only");
getDefaultProperties().setProperty(Environment.STATEMENT_BATCH_SIZE, NO_BATCH);
}
public String getLowercaseFunction() {
return "lcase";
}
public String getAddColumnString() {
return "add column";
}
public boolean dropConstraints() {
return false;
}
public boolean supportsIdentityColumns() {
return true;
}
public String getIdentitySelectString() {
return "values identity_val_local()";
}
public String getIdentityColumnString() {
return "generated by default as identity"; //not null ... (start with 1) is implicit
}
public String getIdentityInsertString() {
return "default";
}
public String getSequenceNextValString(String sequenceName) {
return "values nextval for " + sequenceName;
}
public String getCreateSequenceString(String sequenceName) {
return "create sequence " + sequenceName;
}
public String getDropSequenceString(String sequenceName) {
return "drop sequence " + sequenceName + " restrict";
}
public boolean supportsSequences() {
return true;
}
public boolean supportsPooledSequences() {
return true;
}
public String getQuerySequencesString() {
return "select seqname from sysibm.syssequences";
}
public boolean supportsLimit() {
return true;
}
public boolean supportsVariableLimit() {
return false;
}
// /**
// * Render the <tt>rownumber() over ( .... ) as rownumber_,</tt>
// * bit, that goes in the select list
// */
// private String getRowNumber(String sql) {
// StringBuffer rownumber = new StringBuffer(50)
// .append("rownumber() over(");
//
// int orderByIndex = sql.toLowerCase().indexOf("order by");
//
// if ( orderByIndex>0 && !hasDistinct(sql) ) {
// rownumber.append( sql.substring(orderByIndex) );
// }
//
// rownumber.append(") as rownumber_,");
//
// return rownumber.toString();
// }
//
// public String getLimitString(String sql, boolean hasOffset) {
// int startOfSelect = sql.toLowerCase().indexOf("select");
//
// StringBuffer pagingSelect = new StringBuffer( sql.length()+100 )
// .append( sql.substring(0, startOfSelect) ) // add the comment
// .append("select * from ( select ") // nest the main query in an outer select
// .append( getRowNumber(sql) ); // add the rownnumber bit into the outer query select list
//
// if ( hasDistinct(sql) ) {
// pagingSelect.append(" row_.* from ( ") // add another (inner) nested select
// .append( sql.substring(startOfSelect) ) // add the main query
// .append(" ) as row_"); // close off the inner nested select
// }
// else {
// pagingSelect.append( sql.substring( startOfSelect + 6 ) ); // add the main query
// }
//
// pagingSelect.append(" ) as temp_ where rownumber_ ");
//
// //add the restriction to the outer select
// if (hasOffset) {
// pagingSelect.append("between ?+1 and ?");
// }
// else {
// pagingSelect.append("<= ?");
// }
//
// return pagingSelect.toString();
// }
public String getLimitString(String sql, int offset, int limit) {
if ( offset == 0 ) {
return sql + " fetch first " + limit + " rows only";
}
StringBuilder pagingSelect = new StringBuilder( sql.length() + 200 )
.append(
"select * from ( select inner2_.*, rownumber() over(order by order of inner2_) as rownumber_ from ( "
)
.append( sql ) //nest the main query in an outer select
.append( " fetch first " )
.append( limit )
.append( " rows only ) as inner2_ ) as inner1_ where rownumber_ > " )
.append( offset )
.append( " order by rownumber_" );
return pagingSelect.toString();
}
/**
* DB2 does have a one-based offset, however this was actually already handled in the limit string building
* (the '?+1' bit). To not mess up inheritors, I'll leave that part alone and not touch the offset here.
*
* @param zeroBasedFirstResult The user-supplied, zero-based offset
*
* @return zeroBasedFirstResult
*/
public int convertToFirstRowValue(int zeroBasedFirstResult) {
return zeroBasedFirstResult;
}
//
// private static boolean hasDistinct(String sql) {
// return sql.toLowerCase().indexOf("select distinct")>=0;
// }
public String getForUpdateString() {
return " for read only with rs";
}
public boolean useMaxForLimit() {
return true;
}
public boolean supportsOuterJoinForUpdate() {
return false;
}
public boolean supportsNotNullUnique() {
return false;
}
public String getSelectClauseNullString(int sqlType) {
String literal;
switch(sqlType) {
case Types.VARCHAR:
case Types.CHAR:
literal = "'x'";
break;
case Types.DATE:
literal = "'2000-1-1'";
break;
case Types.TIMESTAMP:
literal = "'2000-1-1 00:00:00'";
break;
case Types.TIME:
literal = "'00:00:00'";
break;
default:
literal = "0";
}
return "nullif(" + literal + ',' + literal + ')';
}
public static void main(String[] args) {
System.out.println( new DB2Dialect().getLimitString("/*foo*/ select * from foos", true) );
System.out.println( new DB2Dialect().getLimitString("/*foo*/ select distinct * from foos", true) );
System.out.println( new DB2Dialect().getLimitString("/*foo*/ select * from foos foo order by foo.bar, foo.baz", true) );
System.out.println( new DB2Dialect().getLimitString("/*foo*/ select distinct * from foos foo order by foo.bar, foo.baz", true) );
}
public boolean supportsUnionAll() {
return true;
}
public int registerResultSetOutParameter(CallableStatement statement, int col) throws SQLException {
return col;
}
public ResultSet getResultSet(CallableStatement ps) throws SQLException {
boolean isResultSet = ps.execute();
// This assumes you will want to ignore any update counts
while (!isResultSet && ps.getUpdateCount() != -1) {
isResultSet = ps.getMoreResults();
}
ResultSet rs = ps.getResultSet();
// You may still have other ResultSets or update counts left to process here
// but you can't do it now or the ResultSet you just got will be closed
return rs;
}
public boolean supportsCommentOn() {
return true;
}
public boolean supportsTemporaryTables() {
return true;
}
public String getCreateTemporaryTableString() {
return "declare global temporary table";
}
public String getCreateTemporaryTablePostfix() {
return "not logged";
}
public String generateTemporaryTableName(String baseTableName) {
return "session." + super.generateTemporaryTableName(baseTableName);
}
public boolean supportsCurrentTimestampSelection() {
return true;
}
public String getCurrentTimestampSelectString() {
return "values current timestamp";
}
public boolean isCurrentTimestampSelectStringCallable() {
return false;
}
/**
* {@inheritDoc}
* <p/>
* DB2 is know to support parameters in the <tt>SELECT</tt> clause, but only in casted form
* (see {@link #requiresCastingOfParametersInSelectClause()}).
*
* @return True.
*/
public boolean supportsParametersInInsertSelect() {
return true;
}
/**
* DB2 in fact does require that parameters appearing in the select clause be wrapped in cast() calls
* to tell the DB parser the type of the select value.
*
* @return True.
*/
public boolean requiresCastingOfParametersInSelectClause() {
return true;
}
public boolean supportsResultSetPositionQueryMethodsOnForwardOnlyCursor() {
return false;
}
//DB2 v9.1 doesn't support 'cross join' syntax
public String getCrossJoinSeparator() {
return ", ";
}
// Overridden informational metadata ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
public boolean supportsEmptyInList() {
return false;
}
public boolean supportsLobValueChangePropogation() {
return false;
}
public boolean doesReadCommittedCauseWritersToBlockReaders() {
return true;
}
public boolean supportsTupleDistinctCounts() {
return false;
}
}