| /* |
| |
| Derby - Class org.apache.derby.impl.sql.compile.UnaryDateTimestampOperatorNode |
| |
| 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.derby.impl.sql.compile; |
| |
| import java.sql.Types; |
| import java.util.List; |
| import org.apache.derby.iapi.error.StandardException; |
| import org.apache.derby.iapi.reference.ClassName; |
| import org.apache.derby.iapi.reference.SQLState; |
| import org.apache.derby.iapi.services.classfile.VMOpcode; |
| import org.apache.derby.iapi.services.compiler.MethodBuilder; |
| import org.apache.derby.iapi.services.context.ContextManager; |
| import org.apache.derby.iapi.types.DataTypeDescriptor; |
| import org.apache.derby.iapi.types.DataValueDescriptor; |
| import org.apache.derby.iapi.types.DataValueFactory; |
| import org.apache.derby.iapi.types.DateTimeDataValue; |
| |
| /** |
| * This class implements the timestamp( x) and date(x) functions. |
| * |
| * These two functions implement a few special cases of string conversions beyond the normal string to |
| * date/timestamp casts. |
| */ |
| class UnaryDateTimestampOperatorNode extends UnaryOperatorNode |
| { |
| private static final String TIMESTAMP_METHOD_NAME = "getTimestamp"; |
| private static final String DATE_METHOD_NAME = "getDate"; |
| |
| // Allowed kinds |
| final static int K_DATE = 0; |
| final static int K_TIMESTAMP = 1; |
| |
| /** |
| * This class is used to hold logically different objects for |
| * space efficiency. {@code kind} represents the logical object |
| * type. See also {@link ValueNode#isSameNodeKind}. |
| */ |
| final int kind; |
| |
| /** |
| * @param operand The operand of the function |
| * @param kind The kind of the result, Date or Timestamp. |
| * @param cm context manager |
| * @throws StandardException |
| */ |
| UnaryDateTimestampOperatorNode( |
| ValueNode operand, |
| int kind, |
| ContextManager cm) throws StandardException { |
| super(operand, |
| kind == K_DATE ? "date" : "timestamp", |
| kind == K_DATE ? DATE_METHOD_NAME : TIMESTAMP_METHOD_NAME, |
| cm); |
| this.kind = kind; |
| setType(DataTypeDescriptor.getBuiltInDataTypeDescriptor( |
| kind == K_DATE ? Types.DATE : Types.TIMESTAMP)); |
| } |
| |
| /** |
| * Called by UnaryOperatorNode.bindExpression. |
| * |
| * If the operand is a constant then evaluate the function at compile time. Otherwise, |
| * if the operand input type is the same as the output type then discard this node altogether. |
| * If the function is "date" and the input is a timestamp then change this node to a cast. |
| * |
| * @param fromList The FROM list for the query this |
| * expression is in, for binding columns. |
| * @param subqueryList The subquery list being built as we find SubqueryNodes |
| * @param aggregates The aggregate list being built as we find AggregateNodes |
| * |
| * @return The new top of the expression tree. |
| * |
| * @exception StandardException Thrown on error |
| */ |
| @Override |
| ValueNode bindExpression ( |
| FromList fromList, SubqueryList subqueryList, List<AggregateNode> aggregates) |
| throws StandardException |
| { |
| boolean isIdentity = false; // Is this function the identity operator? |
| boolean operandIsNumber = false; |
| |
| bindOperand( fromList, subqueryList, aggregates); |
| DataTypeDescriptor operandType = operand.getTypeServices(); |
| switch( operandType.getJDBCTypeId()) |
| { |
| case Types.BIGINT: |
| case Types.INTEGER: |
| case Types.SMALLINT: |
| case Types.TINYINT: |
| case Types.DECIMAL: |
| case Types.NUMERIC: |
| case Types.DOUBLE: |
| case Types.FLOAT: |
| if( TIMESTAMP_METHOD_NAME.equals( methodName)) |
| invalidOperandType(); |
| operandIsNumber = true; |
| break; |
| |
| case Types.CHAR: |
| case Types.VARCHAR: |
| break; |
| |
| case Types.DATE: |
| if( TIMESTAMP_METHOD_NAME.equals( methodName)) |
| invalidOperandType(); |
| isIdentity = true; |
| break; |
| |
| case Types.NULL: |
| break; |
| |
| case Types.TIMESTAMP: |
| if( TIMESTAMP_METHOD_NAME.equals( methodName)) |
| isIdentity = true; |
| break; |
| |
| default: |
| invalidOperandType(); |
| } |
| |
| if( operand instanceof ConstantNode) |
| { |
| DataValueFactory dvf = getLanguageConnectionContext().getDataValueFactory(); |
| DataValueDescriptor sourceValue = ((ConstantNode) operand).getValue(); |
| DataValueDescriptor destValue; |
| if( sourceValue.isNull()) |
| { |
| destValue = (TIMESTAMP_METHOD_NAME.equals( methodName)) |
| ? dvf.getNullTimestamp( (DateTimeDataValue) null) |
| : dvf.getNullDate( (DateTimeDataValue) null); |
| } |
| else |
| { |
| destValue = (TIMESTAMP_METHOD_NAME.equals( methodName)) |
| ? dvf.getTimestamp( sourceValue) : dvf.getDate( sourceValue); |
| } |
| |
| return new UserTypeConstantNode(destValue, getContextManager()); |
| } |
| |
| if( isIdentity) |
| return operand; |
| return this; |
| } // end of bindUnaryOperator |
| |
| private void invalidOperandType() throws StandardException |
| { |
| throw StandardException.newException( SQLState.LANG_UNARY_FUNCTION_BAD_TYPE, |
| getOperatorString(), getOperand().getTypeServices().getSQLstring()); |
| } |
| |
| /** |
| * Do code generation for this unary operator. |
| * |
| * @param acb The ExpressionClassBuilder for the class we're generating |
| * @param mb The method the expression will go into |
| * |
| * |
| * @exception StandardException Thrown on error |
| */ |
| @Override |
| void generateExpression( ExpressionClassBuilder acb, MethodBuilder mb) |
| throws StandardException |
| { |
| acb.pushDataValueFactory( mb); |
| operand.generateExpression( acb, mb); |
| mb.cast( ClassName.DataValueDescriptor); |
| mb.callMethod( VMOpcode.INVOKEINTERFACE, (String) null, methodName, getTypeCompiler().interfaceName(), 1); |
| } // end of generateExpression |
| |
| @Override |
| boolean isSameNodeKind(ValueNode o) { |
| return super.isSameNodeKind(o) && |
| ((UnaryDateTimestampOperatorNode)o).kind == kind; |
| } |
| } |