HubTable

Object
- HubTable

```
public final class HubTable
extends Object
```
The Datahub Table class. Tables can be instantiated by the Datahub SQL create statement. To instantiate a table using the HubTable java constructor, use the Datahub.makeTableFile() method to prepare your TableRow java files, and compile them as part of your application.
Table and column names are not case sensitive and are limited to NAME_MAX characters in length. Subscription names are case sensitive and are not limited in length.
Table data selections are sorted according to the key column values. When you use integer values as key values, the sorting is text value based so values such as 1, 11, and 111 come before 2, 22, 222, etc. The sorted order is a natural aspect of how the data is organized in the table data structures and not the result of an additional sorting step. There is a boolean option, setSortFlag(boolean) which can be set to have the data sorted properly in selection results. The flag is only relevant if one or more of the key columns is a numeric data type.
Accepting the default ordering of numeric key column data without additional sorting is appropriate when wanting to conserve processing for tables with thousands of data rows. Here are some suggestions to work with the default ordering of data:
1. Instead of using the integer type, use the varchar type and format the data to use leading zeros.
2. Use numbers in a range such as 10000-99999 so that the values always have the same number of digits and sort properly.
3. Instead of using a counter for a table key, use a fixed format timestamp string.
4. Java System.currentTimeMillis() values sort correctly by default because each value has the same number of digits.

Field Summary

Fields
Modifier and Type	Field and Description
`Object`	`clientData` for public client use - a reference to anything you want associated with the table
`static int`	`NAME_MAX` A very long name can be used but only the first 31 chars of the name are significant.

Constructor Summary

Constructors
Constructor and Description

HubTable(String name, HubTableRow tr)
Construct a HubTable instance and add it to the Datahub.

Constructors
Constructor and Description
`HubTable(String name, HubTableRow tr)` Construct a HubTable instance and add it to the Datahub.

Method Summary

Methods
Modifier and Type	Method and Description
`String`	`createStatement()` Return an SQL create statement for the table schema
`boolean`	`deleteRow(HubTableRow row)` Delete a row from the table.
`String`	`deleteStatement(HubTableRow row)` Build an SQL delete statement for deleting a row.
`int`	`deleteWhere(String whereClause)` Delete all table rows matching an SQL selection clause.
`boolean`	`drop()` Delete the table.
`String`	`dropStatement()` Obtain an SQL drop statement for deleting the table.
`static String`	`errMsg(int e)` Obtain an error message string for an error code returned by the HubTable methods insert(), update(), and delete().
`HubTableColumn`	`getColumn(String Name)` Lookup a table column by name.
`int`	`getColumnCount()` Obtain the count of table columns.
`String`	`getColumnNameList()` Obtain a whitespace separated list of all the column names.
`String[]`	`getColumnNames()` Obtain the column names as an array
`String`	`getKeyNameList()` Obtain a whitespace separated list of the key column names.
`String[]`	`getKeyNames()` Obtain the key column names as an array
`String`	`getName()` Obtain the table name which is possibly truncated to the maximum length, NAME_MAX, but preserves the original case passed to the constructor.
`int`	`getRowCount()` Obtain the count of table rows.
`TableRowSchema[]`	`getSchema()` Obtain the table schema as data rows
`String`	`getSchemaList()` Obtain the table schema formatted as an SQL selection statement result select {table schema} {{Column Name} Key Type} {{Column Name}} colCount {} data
`String`	`getSchemaList(boolean addEmptyDescriptionColumn)` Obtain the table schema formatted as an SQL selection statement result optionally with an empty Description column added.
`Boolean`	`getSortFlag()` The sortFlag controls whether additional sorting is performed on selection results to sequence numeric data in numeric order.
`int`	`getSubscriptionCount()` Obtain the count of subscriptions to the table.
`TableRowSub[]`	`getSubscriptions()` Obtain an array of the current table subscriptions.
`String`	`getSubscriptionsList()` Obtain the current subscriptions as an SQL selection list.
`int`	`insert(HubTableRow tr)` Add a new row to the table.
`String`	`insertStatement(HubTableRow row, HubTableColumn[] col)` Provide an insert statement encompassing some or all of the column values in the provided row.
`static HubTable`	`load(String tablename)` A counterpart to save() - load a table that was saved on the file system.
`static void`	`main(String[] args)` Create java files for the table row types used internally by the com.hume.datahub package.
`static String`	`nameID(String Name)` Return the case-insensitive, length-limited name used for lookup.
`int`	`put(HubTableRow tr)` The put method combines the action of an insert of a new row or an update if a row with the same primary composite key value already exists.
`String`	`save()` Save the table as sql statements using tablename.tab in the working directory
`HubTableRow[]`	`select(String whereClause)` Find all table rows matching a search condition.
`HubTableRow[]`	`selectAll()` Select all rows from the table.
`HubTableRow`	`selectPCK(String key)` Direct lookup of a single row using the primary composite key value.
`Boolean`	`setDefaultSorting()` A call to set the default sorting behavior.
`Boolean`	`setSortFlag(boolean wantSorting)` The sortFlag controls whether additional sorting is performed on selection results to sequence numeric data in numeric order.
`HubTableWin`	`showDataWin()` Show the Datahub GUI table data window for the table.
`HubTableWin`	`showSchemaWin()` Show the Datahub GUI table schema window.
`HubTableWin`	`showSubsWin()` Show the Datahub GUI table subscription window.
`void`	`subscriptionAddJava(SubscriberItf receiver, String subname, String[] subcols, boolean wantInsert, boolean wantUpdate, boolean wantDelete, boolean wantDrop, boolean wantSync, String whereClause, Object argdata)` Open a table subscription that provides notifications as Java instance data.
`boolean`	`subscriptionAddJavaSync(SubscriberItf receiver, String subname)` Open a table subscription that provides all current and future data as Java instance data.
`void`	`subscriptionAddSql(SubscriberSqlItf sqlReceiver, String subname, String[] subcols, boolean wantCreate, boolean wantInsert, boolean wantUpdate, boolean wantSelect, boolean wantDelete, boolean wantDrop, boolean wantSync, String whereClause, Object argdata)` Open a table subscription that provides SQL statement notifications
`boolean`	`subscriptionAddSqlSync(SubscriberSqlItf sqlReceiver, String subname)` Open a table subscription that provides the table create statement, and all current and future data.
`boolean`	`subscriptionClose(String name)` Close a subscription to the table.
`int`	`update(HubTableRow tr)` Update a single table row where the key is not changing.
`int`	`update(HubTableRow oldRow, HubTableRow newRow)` Update a table row where the key may be changing.
`int`	`update(String key, HubTableRow tr)` Update the single row identified by the key.
`void`	`usageJavaWhereClause(StringBuilder sb)` Return an example Java code where clause with the key column names and concatenating java variable names for their values
`void`	`usageSqlWhereClause(StringBuilder sb)` Provide an example where clause with the key column names and concatenating constants for their values
`boolean`	`usesSortFlag()` If the table uses numeric keys, sorting may be desirable to sequence numeric data in numeric order instead of text sort order which is the default that does not require additional processing.
`String`	`write(String pathname, boolean overWrite)` Write the table data to a file as SQL statements.
`String`	`writeCsv(String pathname)` Export the table as comma separated value data.

Methods inherited from class Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - clientData
```
public Object clientData
```
    for public client use - a reference to anything you want associated with the table
  - NAME_MAX
```
public static final int NAME_MAX
```
    A very long name can be used but only the first 31 chars of the name are significant.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - HubTable
```
public HubTable(String name,
        HubTableRow tr)
```
    Construct a HubTable instance and add it to the Datahub. The passed in data row is used as a model for class information and cloning. However, it is not part of the table data - the table is initialized empty.
    The table name is not case sensitive and is limited to 31 characters in length. It must begin with a letter and include only letters, digits, and the underscore. If the name contains improper characters, the table will be given the literal name invalidName.
    
    Parameters:
    name - table name
    tr - a model table row used for class information and cloning
    
    Throws:
    
    SqlException
- Method Detail
  - createStatement
```
public String createStatement()
```
    Return an SQL create statement for the table schema
  - deleteRow
```
public boolean deleteRow(HubTableRow row)
```
    Delete a row from the table.
    
    Parameters:
    row - the key value of the input row specifies which row is deleted
    
    Returns:
    true if the row was deleted
  - deleteStatement
```
public String deleteStatement(HubTableRow row)
```
    Build an SQL delete statement for deleting a row.
    
    Parameters:
    row -
    
    Returns:
    the SQL statement
  - deleteWhere
```
public int deleteWhere(String whereClause)
                throws SqlException
```
    Delete all table rows matching an SQL selection clause. The "where" keyword is optionally omitted.
    
    Parameters:
    whereClause - an SQL selection expression
    
    Returns:
    the count of rows deleted
    
    Throws:
    
    SqlException - if the where clause syntax is improper
  - drop
```
public boolean drop()
```
    Delete the table.
  - dropStatement
```
public String dropStatement()
```
    Obtain an SQL drop statement for deleting the table.
  - errMsg
```
public static String errMsg(int e)
```
    Obtain an error message string for an error code returned by the HubTable methods insert(), update(), and delete(). The lookup does not include the SqlException error codes.
    
    Parameters:
    e -
    
    Returns:
    an error message
  - getColumn
```
public HubTableColumn getColumn(String Name)
```
    Lookup a table column by name.
    
    Parameters:
    Name -
    
    Returns:
    the column or null if the table has been dropped.
  - getColumnCount
```
public int getColumnCount()
```
    Obtain the count of table columns.
    
    Returns:
    the count of table columns
  - getColumnNameList
```
public String getColumnNameList()
```
    Obtain a whitespace separated list of all the column names. Cached for better performance since it may be used frequently by subscriptions.
    
    Returns:
    column name list
  - getColumnNames
```
public String[] getColumnNames()
```
    Obtain the column names as an array
    
    Returns:
    an ordered array of the table column names.
  - getKeyNameList
```
public String getKeyNameList()
```
    Obtain a whitespace separated list of the key column names. Cached for better performance since it may be used frequently by subscriptions.
    
    Returns:
    key column name list
  - getKeyNames
```
public String[] getKeyNames()
```
    Obtain the key column names as an array
    
    Returns:
    an ordered array of the table key column names.
  - getName
```
public String getName()
```
    Obtain the table name which is possibly truncated to the maximum length, NAME_MAX, but preserves the original case passed to the constructor.
    
    Returns:
    table name
  - getRowCount
```
public int getRowCount()
```
    Obtain the count of table rows.
    
    Returns:
    the count of table rows
  - getSchema
```
public TableRowSchema[] getSchema()
```
    Obtain the table schema as data rows
    
    Returns:
    schema data rows
  - getSchemaList
```
public String getSchemaList()
```
    Obtain the table schema formatted as an SQL selection statement result select {table schema} {{Column Name} Key Type} {{Column Name}} colCount {} data
  - getSchemaList
```
public String getSchemaList(boolean addEmptyDescriptionColumn)
```
    Obtain the table schema formatted as an SQL selection statement result optionally with an empty Description column added. Schema Columns are: {Column Name} Key Type [Description]
  - getSortFlag
```
public Boolean getSortFlag()
```
    The sortFlag controls whether additional sorting is performed on selection results to sequence numeric data in numeric order.
    
    Returns:
    null if the sortFlag has not been set or is not applicable, true or false if the sortFlag has been set.
  - getSubscriptionCount
```
public int getSubscriptionCount()
```
    Obtain the count of subscriptions to the table.
    
    Returns:
    the count of subscriptions to the table
  - getSubscriptions
```
public TableRowSub[] getSubscriptions()
```
    Obtain an array of the current table subscriptions. Modifying a returned value does not modify the corresponding subscription.
    
    Returns:
    an array of table rows
  - getSubscriptionsList
```
public String getSubscriptionsList()
```
    Obtain the current subscriptions as an SQL selection list. The output columns are: tablename subscription openStatement
  - insert
```
public int insert(HubTableRow tr)
```
    Add a new row to the table. The passed row is cloned so that you do not have a reference to the actual row in the table. You can subsequently modify your row without affecting the table data.
    
    Parameters:
    tr - a tablerow that is an instance of the row class passed to the table constructor.
    
    Returns:
    1 if the row was added, ERR_INSERT_UNIQUE_KEY_VIOLATION, or ERR_TABLE_WAS_DROPPED.
  - insertStatement
```
public String insertStatement(HubTableRow row,
                     HubTableColumn[] col)
```
    Provide an insert statement encompassing some or all of the column values in the provided row. The method supports subscription notification and conversion to string for saving or sharing.
    
    Parameters:
    row - input table row
    col - an array of the desired columns or null for all columns
    
    Returns:
    an SQL insert statement
  - load
```
public static HubTable load(String tablename)
                     throws SqlException
```
    A counterpart to save() - load a table that was saved on the file system.
    
    Parameters:
    tablename -
    
    Returns:
    table object reference
    
    Throws:
    
    SqlException
  - main
```
public static void main(String[] args)
```
    Create java files for the table row types used internally by the com.hume.datahub package. Not executed by users.
    
    Parameters:
    args - ignored
  - nameID
```
public static String nameID(String Name)
```
    Return the case-insensitive, length-limited name used for lookup. SQL is not case sensitive for table and column names.
    
    Parameters:
    Name - table or column name identifier
    
    Returns:
    lowercase limited-length identifier
  - put
```
public int put(HubTableRow tr)
```
    The put method combines the action of an insert of a new row or an update if a row with the same primary composite key value already exists.
    
    Parameters:
    tr - input table row
    
    Returns:
    count of rows replaced (0 or 1) or ERR_TABLE_WAS_DROPPED.
  - save
```
public String save()
            throws SqlException
```
    Save the table as sql statements using tablename.tab in the working directory
    
    Throws:
    
    SqlException
  - select
```
public HubTableRow[] select(String whereClause)
                     throws SqlException
```
    Find all table rows matching a search condition. An exception is thrown for improper where clause syntax.
    
    Parameters:
    whereClause -
    
    Returns:
    table row array
    
    Throws:
    
    SqlException
  - selectAll
```
public HubTableRow[] selectAll()
```
    Select all rows from the table.
  - selectPCK
```
public HubTableRow selectPCK(String key)
```
    Direct lookup of a single row using the primary composite key value.
    Parameters:
    key - value is computed from row.getKey() or from TableRowClass.keyOf(key value arguments);
    Our example application creates convenience methods that use this method and cast the result to a specific table row class.
    
    public static HubTable abcd = new HubTable("abcd", new TableRowAbcd()); public static TableRowAbcd getAbcdRow(String a) { String keyValue = TableRowAbcd.keyOf(a); return (TableRowAbcd) abcd.selectPCK(keyValue); }
    The keyOf() method takes the key column values in their sequence order.
    Returns:
    the selected row or null if not found
  - setDefaultSorting
```
public Boolean setDefaultSorting()
```
    A call to set the default sorting behavior. Sorting costs computation effort so we do not sort unless a GUI instance or user requests it.
    
    Returns:
    the sortFlag which is null if not applicable
  - setSortFlag
```
public Boolean setSortFlag(boolean wantSorting)
```
    The sortFlag controls whether additional sorting is performed on selection results to sequence numeric data in numeric order.
    
    Parameters:
    wantSorting - whether to perform additional sorting of selection results
    
    Returns:
    null if the sortFlag has not been set or is not applicable, true or false if the sortFlag has been set.
  - showDataWin
```
public HubTableWin showDataWin()
```
    Show the Datahub GUI table data window for the table.
    
    Returns:
    the window instance
  - showSchemaWin
```
public HubTableWin showSchemaWin()
```
    Show the Datahub GUI table schema window.
    
    Returns:
    the window instance
  - showSubsWin
```
public HubTableWin showSubsWin()
```
    Show the Datahub GUI table subscription window.
    
    Returns:
    the window instance
  - subscriptionAddJava
```
public void subscriptionAddJava(SubscriberItf receiver,
                       String subname,
                       String[] subcols,
                       boolean wantInsert,
                       boolean wantUpdate,
                       boolean wantDelete,
                       boolean wantDrop,
                       boolean wantSync,
                       String whereClause,
                       Object argdata)
                         throws SqlException
```
    Open a table subscription that provides notifications as Java instance data.
    
    Parameters:
    receiver - the receiving object
    subname - a name for the subscription which is unique for subscriptions to this table.
    subcols - null for all columns else an array of column names for the desired table columns
    wantInsert - include new rows
    wantUpdate - include changed rows
    wantDelete - include deleted rows
    wantDrop - include deletion of the table
    wantSync - include existing data when the sub is opened
    whereClause - optionally match only selected table changes.
    argdata - optional client data passed to the notification callback
    
    Throws:
    
    SqlException
  - subscriptionAddJavaSync
```
public boolean subscriptionAddJavaSync(SubscriberItf receiver,
                              String subname)
```
    Open a table subscription that provides all current and future data as Java instance data.
    
    Parameters:
    receiver - the receiving object
    subname - a name for the subscription which is unique for subscriptions to this table.
    
    Returns:
    true for success
  - subscriptionAddSql
```
public void subscriptionAddSql(SubscriberSqlItf sqlReceiver,
                      String subname,
                      String[] subcols,
                      boolean wantCreate,
                      boolean wantInsert,
                      boolean wantUpdate,
                      boolean wantSelect,
                      boolean wantDelete,
                      boolean wantDrop,
                      boolean wantSync,
                      String whereClause,
                      Object argdata)
                        throws SqlException
```
    Open a table subscription that provides SQL statement notifications
    
    Parameters:
    sqlReceiver - the receiving object
    subname - a name for the subscription which is unique for subscriptions to this table.
    subcols - null for all columns else an array of column names for the desired table columns
    wantCreate - include table create statement
    wantInsert - include new rows
    wantUpdate - include changed rows
    wantSelect - include unchanged column values in row update notifications
    wantDelete - include deleted rows
    wantDrop - include deletion of the table
    wantSync - include existing data when the sub is opened
    whereClause - optionally match only selected table changes.
    argdata - optional client data passed to the notification callback
    
    Throws:
    
    SqlException
  - subscriptionAddSqlSync
```
public boolean subscriptionAddSqlSync(SubscriberSqlItf sqlReceiver,
                             String subname)
```
    Open a table subscription that provides the table create statement, and all current and future data.
    
    Parameters:
    sqlReceiver - the receiving object
    subname - a name for the subscription which is unique for subscriptions to this table.
    
    Returns:
    true for success
  - subscriptionClose
```
public boolean subscriptionClose(String name)
```
    Close a subscription to the table.
  - update
```
public int update(HubTableRow tr)
```
    Update a single table row where the key is not changing.
  - update
```
public int update(HubTableRow oldRow,
         HubTableRow newRow)
```
    Update a table row where the key may be changing.
  - update
```
public int update(String key,
         HubTableRow tr)
```
    Update the single row identified by the key. The key value may be changed by the update.
    
    Parameters:
    key - row.getKey() value from before the update
    tr - revised table row
    
    Returns:
    count of row(s) affected or err code
  - usageJavaWhereClause
```
public void usageJavaWhereClause(StringBuilder sb)
```
    Return an example Java code where clause with the key column names and concatenating java variable names for their values
    
    Parameters:
    sb - output text is appended to the passed in StringBuilder
  - usageSqlWhereClause
```
public void usageSqlWhereClause(StringBuilder sb)
```
    Provide an example where clause with the key column names and concatenating constants for their values
    
    Parameters:
    sb - output text is appended to the buffer
  - usesSortFlag
```
public boolean usesSortFlag()
```
    If the table uses numeric keys, sorting may be desirable to sequence numeric data in numeric order instead of text sort order which is the default that does not require additional processing.
    
    Returns:
    Return true if the table has one or more numeric key columns
  - write
```
public String write(String pathname,
           boolean overWrite)
             throws SqlException
```
    Write the table data to a file as SQL statements. HubTable.load() is the restore method.
    
    Parameters:
    pathname - relative or absolute output file pathname
    overWrite - whether to allow overwriting an existing output file
    
    Returns:
    a success message which includes the output pathname and table name
    
    Throws:
    
    SqlException
  - writeCsv
```
public String writeCsv(String pathname)
                throws SqlException
```
    Export the table as comma separated value data. The method will replace an existing output file without error.
    
    Parameters:
    pathname - relative or absolute output file pathname
    
    Returns:
    a success message which includes the table name and output pathname,
    
    Throws:
    
    SqlException

Class HubTable

Field Summary

Constructor Summary

Method Summary

Methods inherited from class Object

Field Detail

clientData

NAME_MAX

Constructor Detail

HubTable

Method Detail

createStatement

deleteRow

deleteStatement

deleteWhere

drop

dropStatement

errMsg

getColumn

getColumnCount

getColumnNameList

getColumnNames

getKeyNameList

getKeyNames

getName

getRowCount

getSchema

getSchemaList

getSchemaList

getSortFlag

getSubscriptionCount

getSubscriptions

getSubscriptionsList

insert

insertStatement

load

main

nameID

put

save

select

selectAll

selectPCK

setDefaultSorting

setSortFlag

showDataWin

showSchemaWin

showSubsWin

subscriptionAddJava

subscriptionAddJavaSync

subscriptionAddSql

subscriptionAddSqlSync

subscriptionClose

update

update

update

usageJavaWhereClause

usageSqlWhereClause

usesSortFlag

write

writeCsv