Deleting Rows from the Store

You delete a single row from the store using the TableAPI.delete() method. Rows are deleted based on a PrimaryKey, which you obtain using the Table.createPrimaryKey() method. You can also require a row to match a specified version before it will be deleted. To do this, use the TableAPI.deleteIfVersion() method. Versions are described in Using Row Versions.

When you delete a row, you must handle the same exceptions as occur when you perform any write operation on the store. See Write Exceptions for a high-level description of these exceptions.

If you delete a row that has associated user-defined row metadata, both the row data and its metadata are permanently removed from the table. This metadata will be included in the change stream event, allowing the change stream subscriber to track the cause of deletion. For more information, see Using row metadata in Write Operations in Developers Guide.

package kvstore.basicExample;

import oracle.kv.KVStore;
import oracle.kv.table.PrimaryKey;
import oracle.kv.table.Table;
import oracle.kv.table.TableAPI;

...

// KVStore handle creation is omitted for brevity

...

TableAPI tableH = kvstore.getTableAPI();

// The name you give to getTable() must be identical
// to the name that you gave the table when you created
// the table using the CREATE TABLE DDL statement.
Table myTable = tableH.getTable("myTable");

// Get the primary key for the row that we want to delete
PrimaryKey primaryKey = myTable.createPrimaryKey();
primaryKey.put("item", "Bolts");

// Delete the row
// This performs a store write operation
tableH.delete(primaryKey, null, null);

Using multiDelete()

You can delete multiple rows at once in a single atomic operation, as long as they all share the shard key values. Recall that shard keys are at least a subset of your primary keys. This results in using a partial primary key, which is the shard key, to perform a multi-delete.

To delete multiple rows at once, use the TableAPI.multiDelete() method.

For example, suppose you create a table like this:

CREATE TABLE myTable (
    itemType STRING,
    itemCategory STRING,
    itemClass STRING,
    itemColor STRING,
    itemSize STRING,
    price FLOAT,
    inventoryCount INTEGER,
    PRIMARY KEY (SHARD(itemType, itemCategory, itemClass), itemColor,
    itemSize)
)

With tables containing data like this:

Row 1:
- itemType: Hats
- itemCategory: baseball
- itemClass: longbill
- itemColor: red
- itemSize: small
- price: 12.07
- inventoryCount: 127
Row 2:
- itemType: Hats
- itemCategory: baseball
- itemClass: longbill
- itemColor: red
- itemSize: medium
- price: 13.07
- inventoryCount: 201
Row 3:
- itemType: Hats
- itemCategory: baseball
- itemClass: longbill
- itemColor: red
- itemSize: large
- price: 14.07
- inventoryCount: 39

In this case, you can delete all the rows sharing the partial primary key Hats, baseball, longbill as follows:

package kvstore.basicExample;

import oracle.kv.KVStore;
import oracle.kv.table.PrimaryKey;
import oracle.kv.table.Table;
import oracle.kv.table.TableAPI;

...

// KVStore handle creation is omitted for brevity

...

TableAPI tableH = kvstore.getTableAPI();

// The name you give to getTable() must be identical
// to the name that you gave the table when you created
// it using the CREATE TABLE DDL statement.
Table myTable = tableH.getTable("myTable");

// Get the primary key for the row that we want to delete
PrimaryKey primaryKey = myTable.createPrimaryKey();
primaryKey.put("itemType", "Hats");
primaryKey.put("itemCategory", "baseball");
primaryKey.put("itemClass", "longbill");

// Exception handling omitted
tableH.multiDelete(primaryKey, null, null);