/**
* drop table with such name
*
* @param tableName - table name
* @return true - if deletion successful. false - if there is no table with such name
*/
public boolean dropTable(String tableName) {
for (DataBase db : databases.values()) {
boolean result = db.dropTable(tableName);
if (!result) {
return false;
}
}
return true;
}
/**
* get all available table names from database
*
* @return - set with table names
*/
public Set<String> getAllAvailableTableNames() {
Set<String> result = new HashSet<String>();
for (DataBase db : databases.values()) {
Set<String> namesOfAvailableTablesInCurrentDB = db.getTableNames();
result.addAll(namesOfAvailableTablesInCurrentDB);
}
return result;
}
/**
* create table with given name and list of column names. Key name has 0 index in the list
*
* @param tableName - name of the table
* @param columnNames - name of columns as list of strings
* @return - if table created successfully. false - if there already exists table with such name
* @throws DataBaseTableException - if something wrong
*/
public boolean createTable(String tableName, List<String> columnNames)
throws DataBaseTableException {
for (DataBase db : databases.values()) {
boolean result = db.createTable(tableName, columnNames);
if (!result) {
return false;
}
}
return true;
}
/**
* remove from table with given name by key
*
* @param tableName - table name
* @param key -
* @return true - if databse modified
* @throws DBUnavailabilityException - database is not available
* @throws DataBaseRequestException - wrong request
* @throws DataBaseTableException - if something wrong with adding data to th table
*/
public boolean removeByKey(String tableName, String key)
throws DBUnavailabilityException, DataBaseRequestException, DataBaseTableException {
if (key == null) {
throw new DataBaseRequestException("key shouldn't be null");
}
String firstCharAtName = key.substring(0, 1);
DataBase db = getDataBaseByKey(firstCharAtName);
return db.removeByKey(tableName, key);
}
/**
* get description for the table with given name
*
* @param tableName - name of the table
* @return column names as string list
* @throws DataBaseTableException - if something wrong
*/
public List<String> getTableDescription(String tableName) throws DataBaseTableException {
TableDescription td = null;
for (DataBase db : databases.values()) {
td = db.getTableDescription(tableName);
if (td != null) {
return td.getColumnNames();
}
}
return null;
}
/**
* get descriptions of all tables in the database
*
* @return set of descriptions, where each descriptions - is a list that contains name of the
* table at 0 index, and column names. Key name has 1 index in list.
*/
public Map<String, TableDescription> getTablesInDataBaseDescription() {
Map<String, TableDescription> result = new HashMap<String, TableDescription>();
for (DataBase db : databases.values()) {
for (TableDescription td : db.getTablesDescriptions()) {
String tableName = td.getName();
if (!result.containsKey(tableName)) {
result.put(tableName, td);
}
}
}
return result;
}
/**
* get all rows from the table with given name
*
* @param tableName table name
* @return all rows
* @throws DataBaseTableException - if something wrong with adding data to th table
*/
public Map<String, Row> getAll(String tableName) throws DataBaseTableException {
Map<String, Row> resultMap = new HashMap<String, Row>();
for (DataBase db : databases.values()) {
Map<String, Row> allInCurrentDB = db.getAll(tableName);
for (String key : allInCurrentDB.keySet()) {
Row row = allInCurrentDB.get(key);
resultMap.put(key, row);
}
}
return resultMap;
}
/**
* update row in the table with given name
*
* @param tableName - table name
* @param args - row
* @return true - if database modified
* @throws DBUnavailabilityException - database is not available
* @throws DataBaseRequestException - wrong request
* @throws DataBaseTableException - if something wrong with adding data to th table
*/
public boolean updateByName(String tableName, List<String> args)
throws DBUnavailabilityException, DataBaseRequestException, DataBaseTableException {
if (args.isEmpty()) {
throw new DataBaseRequestException("zero args in request list");
}
String key = args.get(0);
if (key == null) {
throw new DataBaseRequestException("key shouldn't be null");
}
String firstCharAtName = key.substring(0, 1);
DataBase db = getDataBaseByKey(firstCharAtName);
return db.updateByKey(tableName, args);
}