| /* |
| * 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.db; |
| |
| import java.util.ArrayList; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Set; |
| |
| import org.apache.empire.data.DataType; |
| import org.apache.empire.db.expr.order.DBOrderByExpr; |
| |
| /** |
| * This class is used for building up a partition of a SQL-Command. |
| * It handles the insert from a specified key word between two DBCommandExpr objects. |
| * <P> |
| * |
| * |
| */ |
| public class DBCombinedCmd extends DBCommandExpr |
| { |
| // *Deprecated* private static final long serialVersionUID = 1L; |
| |
| // Members |
| protected DBCommandExpr left; |
| protected DBCommandExpr right; |
| protected String keyWord; |
| |
| /** |
| * Constructs a new DBFuncExpr object and |
| * sets the specified parameters to this object. |
| * |
| * @param left the first DBCommandExpr object |
| * @param keyWord the key word between the two DBCommandExpr objects |
| * @param right the second DBCommandExpr object |
| */ |
| public DBCombinedCmd(DBCommandExpr left, String keyWord, DBCommandExpr right) |
| { |
| this.left = left; |
| this.right = right; |
| this.keyWord = keyWord; |
| } |
| |
| @Override |
| public boolean isValid() |
| { |
| return (left.isValid() && right.isValid()); |
| } |
| |
| /** |
| * Returns the current DBDatabase object. |
| * |
| * @return the current DBDatabase object |
| */ |
| @SuppressWarnings("unchecked") |
| @Override |
| public final DBDatabase getDatabase() |
| { |
| return left.getDatabase(); |
| } |
| |
| /** |
| * @see org.apache.empire.db.DBExpr#addReferencedColumns(Set) |
| */ |
| @Override |
| public void addReferencedColumns(Set<DBColumn> list) |
| { |
| left.addReferencedColumns(list); |
| right.addReferencedColumns(list); |
| } |
| |
| /** |
| * returns whether or not the command has any select expression |
| * @return true if the command has any select expression of false otherwise |
| */ |
| @Override |
| public boolean hasSelectExpr() |
| { |
| return left.hasSelectExpr(); |
| } |
| |
| /** |
| * returns whether or not the command has a specific select expression |
| * @return true if the command contains the given select expression of false otherwise |
| */ |
| @Override |
| public boolean hasSelectExpr(DBColumnExpr expr) |
| { |
| return left.hasSelectExpr(expr); |
| } |
| |
| /** |
| * Returns all select expressions as unmodifiable list |
| * @return the list of DBColumnExpr used for select |
| */ |
| @Override |
| public List<DBColumnExpr> getSelectExpressions() |
| { |
| return left.getSelectExpressions(); |
| } |
| |
| /** |
| * Calls the method dbDBCommandExpr.getSelectExprList from the private variable 'left'. |
| * Returns a array of all DBColumnExpr object of the Vector: 'select'. |
| * |
| * @see org.apache.empire.db.DBCommandExpr#getSelectExprList() |
| * @return returns an array of all DBColumnExpr object of the Vector: 'select' |
| */ |
| @Override |
| public DBColumnExpr[] getSelectExprList() |
| { |
| // DebugMsg(2, "Check: getSelectExprList() for DBCombinedCmd"); |
| return left.getSelectExprList(); |
| } |
| |
| @Override |
| public DBCmdParams getParams() |
| { |
| DBCmdParams lp = left.getParams(); |
| DBCmdParams rp = right.getParams(); |
| if (lp.isEmpty()) |
| return rp; |
| if (rp.isEmpty()) |
| return lp; |
| // combine |
| DBCmdParams params = new DBCmdParams() { |
| final ArrayList<DBCmdParam> list = new ArrayList<DBCmdParam>(lp.size()+rp.size()); |
| { |
| for (DBCmdParam p : lp) |
| list.add(p); |
| for (DBCmdParam p : rp) |
| list.add(p); |
| } |
| @Override |
| public boolean isEmpty() { |
| return list.isEmpty(); |
| } |
| @Override |
| public int size() { |
| return list.size(); |
| } |
| @Override |
| public Iterator<DBCmdParam> iterator() { |
| return list.iterator(); |
| } |
| }; |
| return params; |
| } |
| |
| /** |
| * Returns the list of parameter values for a prepared statement. |
| * To ensure the correct order, getSelect() must be called first. |
| * @return the list of parameter values for a prepared statement |
| */ |
| @Override |
| public Object[] getParamValues() |
| { |
| Object[] leftParams = left.getParamValues(); |
| Object[] rightParams = right.getParamValues(); |
| // Check |
| if (leftParams == null) |
| return rightParams; |
| if (rightParams == null) |
| return leftParams; |
| // Put them all together |
| Object[] allParams = new Object[leftParams.length + rightParams.length]; |
| for (int i = 0; i < leftParams.length; i++) |
| allParams[i] = leftParams[i]; |
| for (int i = 0; i < rightParams.length; i++) |
| allParams[leftParams.length + i] = rightParams[i]; |
| // return Params |
| return allParams; |
| } |
| |
| /** |
| * @return the DataType of the selected expression or DataType.UNKNOWN |
| */ |
| @Override |
| public DataType getDataType() |
| { |
| return left.getDataType(); |
| } |
| |
| /** |
| * Creates the SQL-Command. |
| * |
| * @param sql the SQL-Command |
| */ |
| @Override |
| public void getSelect(DBSQLBuilder sql) |
| { |
| // the left part |
| left.clearOrderBy(); |
| if (!(left instanceof DBCombinedCmd)) |
| { |
| sql.append("("); |
| left.getSelect(sql); |
| sql.append(")"); |
| } |
| else |
| left.getSelect(sql); |
| // concat keyword |
| sql.append("\r\n"); |
| sql.append(keyWord); |
| sql.append("\r\n"); |
| // the right part |
| right.clearOrderBy(); |
| if (!(right instanceof DBCombinedCmd)) |
| { |
| sql.append("("); |
| right.getSelect(sql); |
| sql.append(")"); |
| } |
| else |
| right.getSelect(sql); |
| // done |
| // Add optional Order by statement |
| if (orderBy != null) |
| { // Having |
| sql.append("\r\nORDER BY "); |
| addListExpr(sql, orderBy, CTX_DEFAULT, ", "); |
| } |
| } |
| |
| @Override |
| public DBCommandExpr orderBy(DBOrderByExpr... exprs) |
| { |
| if (orderBy == null) |
| orderBy = new ArrayList<DBOrderByExpr>(); |
| // Add order by expression |
| for (DBOrderByExpr obe : exprs) |
| { |
| DBColumnExpr c = getCmdColumn(obe.getColumn()); |
| orderBy.add(new DBOrderByExpr(c, obe.isDescending())); |
| } |
| return this; |
| } |
| |
| } |