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Java display records from a table based on records in other tables

I'm very new to using databases and SQL in general and I'm having some trouble figuring out a function that will allow me to display records from a table in my jdbc database based on data from other tables in the database. I will illustrate below:
Example of "DEMANDS" table (column headers, "ID" is the primary key):
NAME|ADDRESS|DESTINATION|DATE|TIME|ID
Example of "DRIVERS" table ("REGISTRATION" is the primary key):
USERNAME|PASSWORD|REGISTRATION|NAME
Example of "JOURNEY" table ("JID" is the primary key,"REGISTRATION" is a foreign key)
JID|NAME|ADDRESS|DESTINATION|DISTANCE|REGISTRATION|DATE|TIME|STATUS
Below is the code that I have that is used to display tables on a jsp file:
public String retrieve(String query) throws SQLException {
select(query);
return makeTable(rsToList());//results;
}
private void select(String query){
try {
statement = connection.createStatement();
rs = statement.executeQuery(query);
//statement.close();
}
catch(SQLException e) {
System.out.println("way way"+e);
//results = e.toString();
}
}
private String makeTable(ArrayList list) {
StringBuilder b = new StringBuilder();
String[] row;
b.append("<table border=\"3\">");
for (Object s : list) {
b.append("<tr>");
row = (String[]) s;
for (String row1 : row) {
b.append("<td>");
b.append(row1);
b.append("</td>");
}
b.append("</tr>\n");
} // for
b.append("</table>");
return b.toString();
}//makeHtmlTable
private ArrayList rsToList() throws SQLException {
ArrayList aList = new ArrayList();
ResultSetMetaData metaData = rs.getMetaData();
int count = metaData.getColumnCount(); //number of column
String columnName[] = new String[count];
for (int i = 1; i <= count; i++)
{
columnName[i-1] = metaData.getColumnLabel(i);
}
aList.add(columnName);
int cols = rs.getMetaData().getColumnCount();
while (rs.next()) {
String[] s = new String[cols];
for (int i = 1; i <= cols; i++) {
s[i-1] = rs.getString(i);
}
aList.add(s);
} // while
return aList;
} //rsToList
All of this code works fine and if I pass in a query into the "Retrieve" function such as:
String query = "select * from DRIVERS";
It will display all of the records of the "DRIVERS" table.
What I am wanting to do though, is only list drivers from the driver table that are available at the time specified in the demand (meaning their registration is not currently in a record in the journey table at the same time as the demand) If possible, I would also only like to display the "NAME" and "REGISTRATION" columns as oppose to the whole record.
I would really appreciate some help with this as I've searched around for solutions for quite some time and have not been able to work out a function that will achieve the desired outcome.
Cheers,
Creation of tables script:
-- --------------------------------------------------------
--DROP Table Demands;
CREATE TABLE Demands (
Name varchar(20),
Address varchar(60),
Destination varchar(60),
Date date DEFAULT NULL,
Time time DEFAULT NULL,
Status varchar(15) NOT NULL,
id INT primary key
);
-- --------------------------------------------------------
--DROP Table Drivers;
CREATE TABLE Drivers (
username varchar(20),
password varchar(20),
Registration varchar(10),
Name varchar(20),
PRIMARY KEY (Registration)
);
-- --------------------------------------------------------
--DROP Table Journey;
CREATE TABLE Journey (
jid INT primary key
Destination varchar(60),
Distance integer NOT NULL DEFAULT 1,
Registration varchar(10) NOT NULL,
Date date NOT NULL,
Time time DEFAULT NULL
);

The following query may answer your question.
SELECT Drivers.Name, Drivers.Registration
FROM Drivers
LEFT JOIN Journey ON Journey.Registration = Drivers.Registration
LEFT JOIN Demands ON Demands.Date = Journey.Date
WHERE Demands.id IS NULL;
This joins JOURNEY and DRIVER based on the foreign key relation. It then outer-joins DEMANDS and JOURNEY based on an implicit relation that is DATE. Finally we only keep records that fail the outer join condition.
The model has a major flaw though as the relation between DEMANDS and JOURNEY is based on a field of type Date, as far as one can tell by what your provided.

Cassandra Trigger

I am new to Cassandra and use Cassandra 3.10 and have table like
create table db1.table1 (id text, trip_id text, event_time timestamp, mileage double, primary key(id, event_time));
create table db1.table2 (id text, trip_id text, start_time timestamp, mileage double, primary key(id, start_time));
I need to transfer data from table1 to table2 aggregated by trip_id and sum on mileage and update data in table2
I have written a trigger function to get column name and value
public Collection<Mutation> augment(Partition partition) {
HashMap map = new HashMap();
CFMetaData cfm = partition.metadata();
String tableName = cfm.cfName;
try {
UnfilteredRowIterator it = partition.unfilteredIterator();
while (it.hasNext()) {
Unfiltered un = it.next();
Clustering clt = (Clustering) un.clustering();
Iterator<Cell> cells = partition.getRow(clt).cells().iterator();
while(cells.hasNext()){
Cell cell = cells.next();
map.put(cell.column().name.toString(), cell.value().array());
...
}
}
} catch (Exception e) {
}
...
}
But how can I get Primary key and the value of Primary key? If those are not gettable, how can I use trigger function to do the job?

Yes, It is possible to get primary key and value
To get partition keys column and value use :
List<ColumnDefinition> partitionKeyColumns = cfm.partitionKeyColumns();
ByteBuffer partitionKeyValues = partition.partitionKey().getKey();
To get clustering keys column and value :
List<ColumnDefinition> clusteringKeyColumns = cfm.clusteringColumns();
ByteBuffer[] clusteringKeyValues = clt.getRawValues();

DynamoDB get single column list of range keys or global secondary

I have a DynamoDB table that contains videos info.
Currently "videoID"is the primary (hash) key and "Category" is the range (sort) key.
I want to get a list of all of the "Categories" (Range keys) so I can allow the user to select from one of the available video categories.
https://www.quora.com/What-are-some-good-ways-to-extract-one-single-column-from-a-DynamoDB-table
I was reading that if you modified change the attribute "Category" to a global secondary index you can return the items for that GSI. But I have not been able to find how to do that.
http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSIJavaDocumentAPI.html
So I guess that gives me three questions:
Is there a way to do to find the items in Category by querying just the range key?
If change Category to a GSI can I fiind the items that way?
or
Is the only way of doing it scanning the whole table?
Thanks in advance for your help

Is the only way of doing it scanning the whole table?
-NO, you can implement GSI to avoid it
Is there a way to do to find the items in Category by querying just the range key?
- Yes, If you don't want to scan entire table then you need to create GSI which will have Category as Hash. This GSI will act as a table in itself and you can query on it by passing category values.
If change Category to a GSI can I find the items that way?
-Yes, you can query on GSI with category values
I was reading that if you modified change the attribute "Category" to a global secondary index you can return the items for that GSI. But I have not been able to find how to do that.
-You need to create GSI when you create table, example is given in the link that you have specified once that is done you can query that GSI
References:http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSI.html

Here is the sample code to create Videos table with GSI.
Create "Videos" table with GSI:-
#Autowired
private AmazonDynamoDBClient dynamoDBClient;
public Boolean createTableWithGlobalSecondaryIndex(String tableName) {
CreateTableRequest createTableRequest = null;
DynamoDB dynamoDB = new DynamoDB(dynamoDBClient);
try {
ArrayList<AttributeDefinition> attributeDefinitions = new ArrayList<AttributeDefinition>();
attributeDefinitions.add(new AttributeDefinition().withAttributeName("videoid").withAttributeType("S"));
attributeDefinitions.add(new AttributeDefinition().withAttributeName("category").withAttributeType("S"));
ArrayList<KeySchemaElement> keySchema = new ArrayList<KeySchemaElement>();
keySchema.add(new KeySchemaElement().withAttributeName("videoid").withKeyType(KeyType.HASH));
keySchema.add(new KeySchemaElement().withAttributeName("category").withKeyType(KeyType.RANGE));
// Initial provisioned throughput settings for the indexes
ProvisionedThroughput ptIndex = new ProvisionedThroughput().withReadCapacityUnits(150L)
.withWriteCapacityUnits(150L);
GlobalSecondaryIndex videoCategoryGsi = new GlobalSecondaryIndex().withIndexName("VideoCategoryGsi")
.withProvisionedThroughput(ptIndex)
.withKeySchema(new KeySchemaElement().withAttributeName("category").withKeyType(KeyType.HASH),
new KeySchemaElement().withAttributeName("videoid").withKeyType(KeyType.RANGE))
.withProjection(new Projection().withProjectionType(ProjectionType.ALL));
createTableRequest = new CreateTableRequest().withTableName(tableName).withKeySchema(keySchema)
.withAttributeDefinitions(attributeDefinitions)
.withProvisionedThroughput(
new ProvisionedThroughput().withReadCapacityUnits(100L).withWriteCapacityUnits(100L))
.withGlobalSecondaryIndexes(videoCategoryGsi);
Table table = dynamoDB.createTable(createTableRequest);
table.waitForActive();
} catch (ResourceInUseException re) {
if (re.getErrorMessage().equalsIgnoreCase("Cannot create preexisting table")) {
LOGGER.info("Table already exists =============>" + tableName);
} else if (re.getErrorMessage().contains("Table already exists")) {
LOGGER.info("Table already exists =============>" + tableName);
LOGGER.info("Message =============>" + re.getErrorCode() + ";" + re.getErrorMessage());
} else {
throw new RuntimeException("DynamoDB table cannot be created ...", re);
}
} catch (Exception db) {
throw new RuntimeException("DynamoDB table cannot be created ...", db);
}
return true;
}
Query GSI by category:-
Here is the input is just category and it is querying using GSI. In other words, it is not scanning the entire table as well.
public List<String> findVideosByCategoryUsingGlobalSecondaryIndex(String category) {
List<String> videoAsJson = new ArrayList<>();
DynamoDB dynamoDB = new DynamoDB(dynamoDBClient);
Table table = dynamoDB.getTable("Videos");
Index index = table.getIndex("VideoCategoryGsi");
ItemCollection<QueryOutcome> items = null;
QuerySpec querySpec = new QuerySpec();
querySpec.withKeyConditionExpression("category = :val1")
.withValueMap(new ValueMap()
.withString(":val1", category));
items = index.query(querySpec);
Iterator<Item> pageIterator = items.iterator();
while (pageIterator.hasNext()) {
String videoJson = pageIterator.next().toJSON();
System.out.println("Video json ==================>" + videoJson);
videoAsJson.add(videoJson);
}
return videoAsJson;
}

update database on JTable cell change

I have a window that displays my data based on data in a table, but the trouble is that when I change and I click on the save button I get an error : Error:No value specified for parameter 1.
But I do not want to change all columns just the latest
enregistrer.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e)
{
int row = table.getSelectedRow();
int col = table.getSelectedColumn();
String sql = null;
try {
if(col==4)
sql = "UPDATE impaye" + "SET Impayé = ?" + "WHERE ID = ? "+ row;
preStat =(PreparedStatement) connexion.prepareStatement(sql);
preStat.setObject(1, table.getValueAt(row, col));
preStat.executeUpdate();
preStat.close();
} catch (SQLException insertException) {
System.out.println("Error:"+insertException.getMessage());
}
}
});

But I do not want to change all columns just the latest
Well then you need to change your SQL. Currently your SQL updates all 4 columns.
If you only want to update a single column, then you need 4 SQL statements. The statement you use will be based on the index of the column that was changed.
Something like:
String sql = null;
if (col == 0)
sql = "UPDATE impaye SET Date = ? " + row;
else if (col == 1)
sql = "UPDATE impaye SET Débiteur = ? " + row);
else if
...
preStat =(PreparedStatement) connexion.prepareStatement(sql);
preStat.setObject(1, table.getValueAt(row, col));
preStat.executeUpdate();
I think you will also need a "where" clause in your SQL. I don't think you can just specify a row number (but I don't know much about SQL).

Excluding Foreign Keys From Being Included in a JTable Displaying a ResultSet

I have a JTable with a default table model which I am using to display a result set. I am using postgreSQL. I am trying to get the table to exclude Primary and foreign keys. So far I have gotten it to exclude the primary keys but I have been unsuccessful in excluding the foreign keys.
This is how I am getting the foreign keys:
public List<String> getFKeyData(String tableName, int i) throws SQLException {
DatabaseMetaData dm = connection.getMetaData();
ResultSet rs = dm.getImportedKeys(null, null, tableName);
ArrayList<String> fkTableData = new ArrayList<>();
while (rs.next()) {
fkTableData.add(rs.getString(i));
}
return fkTableData;
}
This is how I initially thought to exclude the foreign keys:
int fkSize = databaseConnection.getFKeyData(tableName, 8).size();
for (int i = 0; i <= fkSize - 1; i++) {
if (databaseConnection.getColumnNames(tableName).indexOf(databaseConnection.getFKeyData(tableName, 8).get(i)) == 1) {
if (databaseConnection.getColumnNames(tableName).indexOf(databaseConnection.getPKey(tableName)) != 1) {
if (databaseConnection.getColCount(tableName) >= 1) {
model.addColumn(columnNamesV.get(1), cellData1);
}
}
}
}
I now realize this was foolish because although it does exclude the foreign key it is added to the model anyway by the for statement. Does anyone know a way around this?

Instead of using DefaultTableModel, extend AbstractTableModel, in which you can control the results returned by getColumnCount() and getValueAt().

This is what I wanted. Simple but it works the way I want it to.
ArrayList fkIndex = new ArrayList();
for (int i = 0; i <= fkSize - 1; i++){
fkIndex.add(databaseConnection.getColumnNames(tableName).indexOf(databaseConnection.getFKeyData(tableName, 8).get(i)));
}
if (databaseConnection.getColumnNames(tableName).indexOf(
databaseConnection.getPKey(tableName)) != 1) {
if (fkIndex.contains(1) == false) {
if (databaseConnection.getColCount(tableName) >= 1) {
model.addColumn(columnNamesV.get(1), cellData1);
}
}
}