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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.empire.dbms.h2;
import java.sql.Connection;
import java.util.GregorianCalendar;
import org.apache.empire.data.DataType;
import org.apache.empire.db.DBColumnExpr;
import org.apache.empire.db.DBCommand;
import org.apache.empire.db.DBDDLGenerator;
import org.apache.empire.db.DBDDLGenerator.DDLActionType;
import org.apache.empire.db.DBDatabase;
import org.apache.empire.db.DBObject;
import org.apache.empire.db.DBSQLBuilder;
import org.apache.empire.db.DBSQLScript;
import org.apache.empire.db.DBTable;
import org.apache.empire.db.DBTableColumn;
import org.apache.empire.dbms.DBMSFeature;
import org.apache.empire.dbms.DBMSHandler;
import org.apache.empire.dbms.DBMSHandlerBase;
import org.apache.empire.dbms.DBSqlPhrase;
import org.apache.empire.exceptions.InvalidArgumentException;
import org.apache.empire.exceptions.NotSupportedException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This class provides support for the H2 database system.
*
*
*/
public class DBMSHandlerH2 extends DBMSHandlerBase
{
// *Deprecated* private static final long serialVersionUID = 1L;
private static final Logger log = LoggerFactory.getLogger(DBMSHandlerH2.class);
/**
* Defines the H2 command type.
*/
public static class DBCommandH2 extends DBCommand
{
// *Deprecated* private static final long serialVersionUID = 1L;
protected int limitRows = -1;
protected int skipRows = 0;
public DBCommandH2(DBMSHandlerH2 dbms, boolean autoPrepareStmt)
{
super(dbms, autoPrepareStmt);
}
@Override
public DBCommand limitRows(int limitRows)
{
// set limit
this.limitRows = limitRows;
return this;
}
@Override
public DBCommand skipRows(int skipRows)
{
if (skipRows<0)
throw new InvalidArgumentException("skipRows", skipRows);
// set skip
this.skipRows = skipRows;
return this;
}
@Override
public void clearLimit()
{
// remove skip and limit
this.limitRows = -1;
this.skipRows = 0;
}
@Override
public void getSelect(DBSQLBuilder sql)
{ // Prepares statement
super.getSelect(sql);
// add limit and offset
if (limitRows>=0)
{ sql.append("\r\nLIMIT ");
sql.append(String.valueOf(limitRows));
// Offset
if (skipRows>0)
{ sql.append(" OFFSET ");
sql.append(String.valueOf(skipRows));
}
}
}
}
// Properties
private String databaseName = null;
// Sequence treatment
// When set to 'false' (default) H2's autoincrement feature is used.
private boolean useSequenceTable = false;
private String sequenceTableName = "Sequences";
private DBDDLGenerator ddlGenerator = null; // lazy creation
/**
* Constructor for the H2 database dbms.
*/
public DBMSHandlerH2()
{
// Default Constructor
}
/**
* returns the name for the database / schema
* @return the database / schema name
*/
public String getDatabaseName()
{
return databaseName;
}
/**
* Sets the name for the database / schema
* This names is required for creating a database.
* When a name is set, the dbms will automatically execute 'USE dbname' when the database is opened.
* @param databaseName the name of the database
*/
public void setDatabaseName(String databaseName)
{
this.databaseName = databaseName;
}
/**
* returns whether a sequence table is used for record identiy management.
* Default is false. In this case the AutoIncrement feature of H2 is used.
* @return true if a sequence table is used instead of identity columns.
*/
public boolean isUseSequenceTable()
{
return useSequenceTable;
}
/**
* If set to true a special table is used for sequence number generation.
* Otherwise the AutoIncrement feature of H2 is used identiy fields.
* @param useSequenceTable true to use a sequence table or false otherwise.
*/
public void setUseSequenceTable(boolean useSequenceTable)
{
this.useSequenceTable = useSequenceTable;
}
/**
* returns the name of the sequence table
* @return the name of the table used for sequence number generation
*/
public String getSequenceTableName()
{
return sequenceTableName;
}
/**
* Sets the name of the sequence table.
* Only applicable if useSequenceTable is set to true.
* @param sequenceTableName the name of the table used for sequence number generation
*/
public void setSequenceTableName(String sequenceTableName)
{
this.sequenceTableName = sequenceTableName;
}
/**
* Creates a new H2 command object.
*
* @return the new DBCommandDerby object
*/
@Override
public DBCommand createCommand(boolean autoPrepareStmt)
{
// create command object
return new DBCommandH2(this, autoPrepareStmt);
}
/**
* Returns whether or not a particular feature is supported by this dmbs
* @param type type of requrested feature. @see DBMSFeature
* @return true if the features is supported or false otherwise
*/
@Override
public boolean isSupported(DBMSFeature type)
{
switch (type)
{ // return support info
case CREATE_SCHEMA: return true;
case SEQUENCES: return useSequenceTable;
case QUERY_LIMIT_ROWS: return true;
case QUERY_SKIP_ROWS: return true;
default:
// All other features are not supported by default
return false;
}
}
/**
* Gets an sql phrase template for this database system.
* @see DBMSHandler#getSQLPhrase(DBSqlPhrase)
* @return the phrase template
*/
@Override
public String getSQLPhrase(DBSqlPhrase phrase)
{
switch (phrase)
{
// sql-phrases
case SQL_NULL: return "null";
case SQL_PARAMETER: return " ? ";
case SQL_RENAME_TABLE: return " ";
case SQL_RENAME_COLUMN: return " AS ";
case SQL_DATABASE_LINK: return "@";
case SQL_QUOTES_OPEN: return "\"";
case SQL_QUOTES_CLOSE: return "\"";
case SQL_CONCAT_EXPR: return "concat(?, {0})";
// data types
case SQL_BOOLEAN_TRUE: return "1";
case SQL_BOOLEAN_FALSE: return "0";
case SQL_CURRENT_DATE: return "CURRENT_DATE";
case SQL_DATE_PATTERN: return "yyyy-MM-dd";
case SQL_DATE_TEMPLATE: return "'{0}'";
case SQL_CURRENT_TIME: return "CURRENT_TIME";
case SQL_TIME_PATTERN: return "HH:mm:ss";
case SQL_TIME_TEMPLATE: return "'{0}'";
case SQL_DATETIME_PATTERN: return "yyyy-MM-dd HH:mm:ss";
case SQL_DATETIME_TEMPLATE: return "'{0}'";
case SQL_CURRENT_TIMESTAMP: return "NOW()";
case SQL_TIMESTAMP_PATTERN: return "yyyy-MM-dd HH:mm:ss";
case SQL_TIMESTAMP_TEMPLATE: return "'{0}'";
// functions
case SQL_FUNC_COALESCE: return "coalesce(?, {0})";
case SQL_FUNC_SUBSTRING: return "substring(?, {0})";
case SQL_FUNC_SUBSTRINGEX: return "substring(?, {0}, {1})";
case SQL_FUNC_REPLACE: return "replace(?, {0}, {1})";
case SQL_FUNC_REVERSE: return "reverse_not_available_in_h2(?)";
case SQL_FUNC_STRINDEX: return "instr(?, {0})";
case SQL_FUNC_STRINDEXFROM: return "locate({0}, ?, {1})";
case SQL_FUNC_LENGTH: return "length(?)";
case SQL_FUNC_UPPER: return "upper(?)";
case SQL_FUNC_LOWER: return "lcase(?)";
case SQL_FUNC_TRIM: return "trim(?)";
case SQL_FUNC_LTRIM: return "ltrim(?)";
case SQL_FUNC_RTRIM: return "rtrim(?)";
case SQL_FUNC_ESCAPE: return "? escape {0:VARCHAR}";
// Numeric
case SQL_FUNC_ABS: return "abs(?)";
case SQL_FUNC_ROUND: return "round(?,{0})";
case SQL_FUNC_TRUNC: return "truncate(?,{0})";
case SQL_FUNC_CEILING: return "ceiling(?)";
case SQL_FUNC_FLOOR: return "floor(?)";
case SQL_FUNC_MOD: return "mod(?,{0})";
case SQL_FUNC_FORMAT: return "format(?, {0:VARCHAR})";
// Date
case SQL_FUNC_DAY: return "day(?)";
case SQL_FUNC_MONTH: return "month(?)";
case SQL_FUNC_YEAR: return "year(?)";
// Aggregation
case SQL_FUNC_SUM: return "sum(?)";
case SQL_FUNC_MAX: return "max(?)";
case SQL_FUNC_MIN: return "min(?)";
case SQL_FUNC_AVG: return "avg(?)";
// Others
case SQL_FUNC_DECODE: return "case ? {0} end";
case SQL_FUNC_DECODE_SEP: return " ";
case SQL_FUNC_DECODE_PART: return "when {0} then {1}";
case SQL_FUNC_DECODE_ELSE: return "else {0}";
// Not defined
default:
// log.warn("SQL phrase " + phrase.name() + " is not defined!");
return phrase.getSqlDefault();
}
}
/**
* @see DBMSHandler#getConvertPhrase(DataType, DataType, Object)
*/
@Override
public String getConvertPhrase(DataType destType, DataType srcType, Object format)
{
switch(destType)
{
case BOOL: return "CAST(? AS UNSIGNED)";
case INTEGER: return "CAST(? AS SIGNED)";
case DECIMAL: return "CAST(? AS DECIMAL)";
case FLOAT: return "CAST(? AS DECIMAL)";
case DATE: return "CAST(? AS DATE)";
case TIME: return "CAST(? AS TIME)";
case DATETIME:
case TIMESTAMP: return "CAST(? AS DATETIME)";
// Convert to text
case VARCHAR:
case CHAR:
return "CAST(? AS CHAR)";
case BLOB:
return "CAST(? AS BLOB)";
// Unknown Type
default:
log.error("getConvertPhrase: unknown type " + destType);
return "?";
}
}
/**
* @see DBMSHandlerBase#getNextSequenceValue(DBDatabase, String, int, Connection)
*/
@Override
public Object getNextSequenceValue(DBDatabase db, String seqName, int minValue, Connection conn)
{ //Use Oracle Sequences
if (useSequenceTable)
{ // Use a sequence Table to generate Sequences
DBTable t = db.getTable(sequenceTableName);
return ((DBSeqTable)t).getNextValue(seqName, minValue, conn);
}
else
{ // Post Detection
return null;
}
}
/**
* @see DBMSHandlerBase#getNextSequenceValueExpr(DBTableColumn col)
*/
@Override
public DBColumnExpr getNextSequenceValueExpr(DBTableColumn column)
{
throw new NotSupportedException(this, "getNextSequenceValueExpr");
}
/**
* Overridden. Returns a timestamp that is used for record updates created by the database server.
*
* @return the current date and time of the database server.
*/
@Override
public java.sql.Timestamp getUpdateTimestamp(Connection conn)
{
// Default implementation
GregorianCalendar cal = new GregorianCalendar();
return new java.sql.Timestamp(cal.getTimeInMillis());
}
/**
* @see DBMSHandler#getDDLScript(DDLActionType, DBObject, DBSQLScript)
*/
@Override
public void getDDLScript(DDLActionType type, DBObject dbo, DBSQLScript script)
{
if (ddlGenerator==null)
ddlGenerator = new H2DDLGenerator(this);
// forward request
ddlGenerator.getDDLScript(type, dbo, script);
}
}
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