| java.lang.Object
 org.xorm.datastore.Row
| Row | | public class Row implements Cloneable(Code) | | A row represents a single instance of a data object. The structure
of a Row is defined by its reference to a Table. The terms Row and
Table could be changed to "Data Object" and "Datatype"; they were
chosen to correspond to a relational database notion but are in no
way tied to any particular implementation.
A Row contains only primitive values; that is, there are no references
to first class objects. When used with a relational database, an
instance of the Row class is meant to correspond exactly with a single
row in a database table. Foreign keys and primary keys are typically
expressed as numeric IDs.
Each instance of a Row tracks values for each Column specified for a
Table. The column values may or may not have been loaded from
persistent storage. This can be tested for using the containsValue()
method. If the value has been set -- even to null -- containsValue()
will return "true".
A row also tracks dirty bits for each Column. A value is said to be
dirty if it has been changed since the first time it was set.
DatastoreDriver implementations are encouraged to use this information
to optimize the update() operation.
Finally, a Row is said to be "hollow" if no values other than the
primary key have been set.
Because it is possible to have a Table without a primary key
(for example, a many-to-many table in a relational database),
the getPrimaryKeyValue() method is not guaranteed to return a
value.
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| Constructor Summary | |
| public | Row(Table table)
Constructs a new, hollow row that references the given Table. | | public | Row(Table table, Object primaryKey)
Constructs a new, hollow row with the given primary key. |
| Row | | public Row(Table table)(Code) | | Constructs a new, hollow row that references the given Table.
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| Row | | public Row(Table table, Object primaryKey)(Code) | | Constructs a new, hollow row with the given primary key.
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| clean | | public void clean()(Code) | | Clears all dirty bits.
|
| clone | | public Object clone()(Code) | | Creates a clone of this Row's contents. Because a Row
only contains immutable data (Integer, String, etc.)
the contents are merely shallow-cloned.
A cloned Row becomes clean if it wasn't already.
|
| containsValue | | public boolean containsValue(Column column)(Code) | | Returns true if the row contains a value for the given column,
even if the value is null.
|
| equals | | public boolean equals(Object o)(Code) | | Tests row equality. Two rows are equal if their entire state
matches. That is, they are both for the same table and each
column configured for their table is equal.
|
| getPrimaryKeyValue | | public Object getPrimaryKeyValue()(Code) | | Convenience method.
Returns the value of the primary key for this row, or null
if no key has been assigned.
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| getTable | | public Table getTable()(Code) | | Returns the Table that this Row is conceptually part of.
|
| getValue | | public Object getValue(Column column)(Code) | | Get the value for the given column. If no value has been set,
returns null. To differentiate between a null value and a
"not present" status, use the containsValue() method.
|
| isCached | | public synchronized boolean isCached()(Code) | | Is this Row cached?
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| isDirty | | public boolean isDirty(Column column)(Code) | | Returns true if the specified column value is dirty.
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| isDirty | | public boolean isDirty()(Code) | | Returns true if any column values are dirty.
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| isHollow | | public boolean isHollow()(Code) | | Returns true if the row is hollow. See the description above.
|
| makeDirty | | public void makeDirty(Column column)(Code) | | Explicitly makes a column dirty. Generally this is not
necessary, but it can be used to force an update.
|
| makeHollow | | public void makeHollow()(Code) | | Makes the Row hollow by clearing all values except the
primaryKey.
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| setCached | | public synchronized void setCached(boolean val)(Code) | | Set the cached flag
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| setPrimaryKeyValue | | public void setPrimaryKeyValue(Object value)(Code) | | |
| setValue | | public boolean setValue(Column column, Object value)(Code) | | Set the value for the given column. Currently this does no
typechecking. If the field is being set for the first time
(i.e., containsValue(column) would return false before this call)
the dirty bit will not be set. Otherwise, if the new value
is different from the old value, the dirty bit will be set.
the new value of the dirty bit for the column |
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