com.wm.app.tn.db
Class TableExpression

java.lang.Object
  com.wm.app.tn.util.TNFixedData
      com.wm.app.tn.db.TableExpression

All Implemented Interfaces:

com.wm.data.IData, java.lang.Cloneable

public class TableExpression
extends com.wm.app.tn.util.TNFixedData

This represents the table expression in a SELECT statement. It's represented in this way so that ISQLHelper implementations can generate join statements in a database-specific way. This isn't too big a deal for single-table selects and simple joins, but the SQL for (e.g.) a left outer join can be ugly and DB-dependent.

Nested Class Summary

Nested classes/interfaces inherited from class com.wm.app.tn.util.TNFixedData

com.wm.app.tn.util.TNFixedData.TreeCursor

Field Summary

static java.lang.String	J_FULL_OUTER
static java.lang.String	J_INNER
static java.lang.String	J_LEFT_OUTER
static java.lang.String	J_RIGHT_OUTER

Constructor Summary

TableExpression()
Create a new TableExpression.

Method Summary

void	addJoin(java.lang.String[] join) Add a table join.
void	addJoin(java.lang.String type, java.lang.String table, java.lang.String alias, java.lang.String on) Add a table join.
java.lang.String[]	getBaseTable() Get stored information about the base table.
java.util.Enumeration	getJoins() Get the list of joined-in tables.
void	setBaseTable(java.lang.String table, java.lang.String alias) Set the base table for this select.

Methods inherited from class com.wm.app.tn.util.TNFixedData

clone, dataSize, get, get, getCursor, getHashCursor, getIndexCursor, getKey, getSharedCursor, getTreeCursor, indexOf, merge, set, set, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

J_INNER

public static final java.lang.String J_INNER

See Also:

Constant Field Values

J_LEFT_OUTER

public static final java.lang.String J_LEFT_OUTER

See Also:

Constant Field Values

J_RIGHT_OUTER

public static final java.lang.String J_RIGHT_OUTER

See Also:

Constant Field Values

J_FULL_OUTER

public static final java.lang.String J_FULL_OUTER

See Also:

Constant Field Values

Constructor Detail

TableExpression

public TableExpression()

Create a new TableExpression.

Method Detail

setBaseTable

public void setBaseTable(java.lang.String table,
                         java.lang.String alias)

Set the base table for this select. This can be aliased, as in the following simple SQL: SELECT d.DocID FROM BizDoc d

Parameters:

table - the name of the table (e.g. "BizDoc")

alias - the alias to use (e.g. "d")

getBaseTable

public java.lang.String[] getBaseTable()

Get stored information about the base table.

Returns:

{ table, alias }

addJoin

public void addJoin(java.lang.String type,
                    java.lang.String table,
                    java.lang.String alias,
                    java.lang.String on)

Add a table join.

Parameters:

type - the type of join (e.g. J_INNER)

table - the name of the table to join in (e.g. "BizDocAttribute")

alias - the alias of the table in the stmt (e.g. "bda0")

on - a SQL expression describing the criteria on which to join

addJoin

public void addJoin(java.lang.String[] join)

Add a table join.

Parameters:

join - the join as { type, table, alias, on }

getJoins

public java.util.Enumeration getJoins()

Get the list of joined-in tables.

Returns:

an enumeration of String[] representing the joins (null if there are none)