nz.co.gregs.dbvolution.actions.DBUpdateToPreviousValues Maven / Gradle / Ivy
/*
* Copyright 2013 Gregory Graham.
*
* Licensed 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 nz.co.gregs.dbvolution.actions;
import java.util.List;
import nz.co.gregs.dbvolution.databases.DBDatabase;
import nz.co.gregs.dbvolution.DBRow;
import nz.co.gregs.dbvolution.databases.definitions.DBDefinition;
import nz.co.gregs.dbvolution.datatypes.QueryableDatatype;
import nz.co.gregs.dbvolution.expressions.BooleanExpression;
import nz.co.gregs.dbvolution.internal.properties.PropertyWrapper;
/**
* Provides support for the abstract concept of updating rows to the previous
* value of the updated columns.
*
*
* Used to provide revert actions for updates.
*
*
* Support DBvolution at
* Patreon
*
* @author Gregory Graham
*/
public class DBUpdateToPreviousValues extends DBUpdateSimpleTypes {
DBUpdateToPreviousValues(DBRow row) {
super(row);
}
/**
* Creates the required SET clause of the UPDATE statement.
*
* @param db the target database
* @param row the row to be updated
* Support DBvolution at
* Patreon
* @return The SET clause of the UPDATE statement.
*/
@Override
protected String getSetClause(DBDatabase db, DBRow row) {
DBDefinition defn = db.getDefinition();
StringBuilder sql = new StringBuilder();
List fields = row.getColumnPropertyWrappers();
String separator = defn.getStartingSetSubClauseSeparator();
for (PropertyWrapper field : fields) {
if (field.isColumn()) {
final QueryableDatatype qdt = field.getQueryableDatatype();
if (qdt.hasChanged()) {
String previousSQLValue = qdt.getPreviousSQLValue(defn);
if (previousSQLValue == null) {
previousSQLValue = defn.getNull();
}
String columnName = field.columnName();
sql.append(separator)
.append(defn.formatColumnName(columnName))
.append(defn.getEqualsComparator())
.append(previousSQLValue);
separator = defn.getSubsequentSetSubClauseSeparator();
}
}
}
return sql.toString();
}
/**
* Creates the WHERE clause of the UPDATE statement.
*
* @param db the target database
* @param row the row to be updated
* Support DBvolution at
* Patreon
* @return The WHERE clause of the UPDATE statement.
*/
@Override
protected String getWhereClause(DBDatabase db, DBRow row) {
DBDefinition defn = db.getDefinition();
StringBuilder sqlString = new StringBuilder();
List> primaryKeys = row.getPrimaryKeys();
String separator = "";
if (primaryKeys.size() > 0) {
for (QueryableDatatype pk : primaryKeys) {
PropertyWrapper wrapper = row.getPropertyWrapperOf(pk);
String pkValue = pk.toSQLString(defn);
sqlString.append(separator).append(defn.formatColumnName(wrapper.columnName())).append(defn.getEqualsComparator()).append(pkValue);
separator = defn.beginAndLine();
}
} else {
for (PropertyWrapper prop : row.getColumnPropertyWrappers()) {
QueryableDatatype qdt = prop.getQueryableDatatype();
if (qdt.isNull()) {
sqlString.append(separator).append(BooleanExpression.isNull(row.column(qdt)).toSQLString(defn));
} else {
sqlString.append(separator).append(prop.columnName()).append(defn.getEqualsComparator()).append(qdt.toSQLString(defn));
}
separator = defn.beginAndLine();
}
}
return sqlString.toString();
}
}