Repository: empire-db Updated Branches: refs/heads/master ffe2eb52a -> 59db7a5b0
EMPIREDB-238 added column expression for scalar functions Project: http://git-wip-us.apache.org/repos/asf/empire-db/repo Commit: http://git-wip-us.apache.org/repos/asf/empire-db/commit/59db7a5b Tree: http://git-wip-us.apache.org/repos/asf/empire-db/tree/59db7a5b Diff: http://git-wip-us.apache.org/repos/asf/empire-db/diff/59db7a5b Branch: refs/heads/master Commit: 59db7a5b08abfc1494149cd30d0e8dc14b4ce16f Parents: ffe2eb5 Author: Rainer Döbele <[email protected]> Authored: Mon Mar 7 18:54:12 2016 +0100 Committer: Rainer Döbele <[email protected]> Committed: Mon Mar 7 18:54:12 2016 +0100 ---------------------------------------------------------------------- .../empire/db/expr/column/DBScalarExpr.java | 199 +++++++++++++++++++ 1 file changed, 199 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/empire-db/blob/59db7a5b/empire-db/src/main/java/org/apache/empire/db/expr/column/DBScalarExpr.java ---------------------------------------------------------------------- diff --git a/empire-db/src/main/java/org/apache/empire/db/expr/column/DBScalarExpr.java b/empire-db/src/main/java/org/apache/empire/db/expr/column/DBScalarExpr.java new file mode 100644 index 0000000..574aab4 --- /dev/null +++ b/empire-db/src/main/java/org/apache/empire/db/expr/column/DBScalarExpr.java @@ -0,0 +1,199 @@ +/* + * 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.expr.column; + +// Java +import java.util.Set; + +import org.apache.empire.commons.StringUtils; +import org.apache.empire.data.DataType; +import org.apache.empire.db.DBColumn; +import org.apache.empire.db.DBColumnExpr; +import org.apache.empire.db.DBDatabase; +import org.apache.empire.xml.XMLUtil; +import org.w3c.dom.Element; + + +/** + * This class is used for declaring scalar functions in SQL (like e.g. random). + * <P> + * + */ +public class DBScalarExpr extends DBColumnExpr +{ + private final static long serialVersionUID = 1L; + + public final DBDatabase db; + public final DataType dataType; + public final String template; + protected Object[] params; + + /** + * Constructs a new DBValueExpr object. + * + * @param db the database + * @param value the value for this constant + * @param type the data type for this constant + */ + public DBScalarExpr(DBDatabase db, String template, Object[] params, DataType dataType) + { + this.db = db; + this.dataType = dataType; + this.template = template; + this.params = params; + } + + /** + * Constructs a new DBValueExpr object. + * + * @param db the database + * @param value the value for this constant + * @param type the data type for this constant + */ + public DBScalarExpr(DBDatabase db, String template, Object param, DataType dataType) + { + this.db = db; + this.dataType = dataType; + this.template = template; + this.params = new Object[] { param }; + } + + /** + * return the value associated with this value expression + * @return the current value + */ + public Object[] getParams() + { + return params; + } + + /** + * set the value associated with this value expression + * @param the value + */ + public void setParams(Object[] params) + { + this.params = params; + } + + /** + * Returns the current DBDatabase object. + * + * @return the current DBDatabase object + */ + @Override + public DBDatabase getDatabase() + { + return db; + } + + /** + * Returns the data type of the DBColumnExpr object. + * + * @return the data type + */ + @Override + public DataType getDataType() + { + return dataType; + } + + /** + * Returns the column name. + * + * @return the column name + */ + @Override + public String getName() + { + return null; + } + + /** this helper function calls the DBColumnExpr.addXML(Element, long) method */ + @Override + public Element addXml(Element parent, long flags) + { + Element elem; + // Add a column expression for this function + elem = XMLUtil.addElement(parent, "column"); + String name = getName(); + if (name!=null) + elem.setAttribute("name", getName()); + // Add Other Attributes + if (attributes!=null) + attributes.addXml(elem, flags); + // Done + elem.setAttribute("function", template); + return elem; + } + + /** + * Returns null. + * + * @return null + */ + @Override + public DBColumn getUpdateColumn() + { + return null; + } + + /** + * Always returns false since value expressions cannot be an aggregate. + * + * @return false + */ + @Override + public boolean isAggregate() + { + return false; + } + + /** + * @see org.apache.empire.db.DBExpr#addReferencedColumns(Set) + */ + @Override + public void addReferencedColumns(Set<DBColumn> list) + { + return; + } + + /** + * Creates the SQL-Command. + * + * @param buf the SQL-Command + * @param context the current SQL-Command context + */ + @Override + public void addSQL(StringBuilder buf, long context) + { + // Get Text from Template + String text = this.template; + if (params != null) + { // Replace Params + for (int i = 0; i < params.length; i++) + { // String test =(params[i] != null) ? params[i].toString() : ""; + String value = getObjectValue(dataType, params[i], CTX_DEFAULT, ","); + text = StringUtils.replaceAll(template, "{"+ String.valueOf(i) + "}", value); + } + } + buf.append(text); + } + +}
