Examples with Delete org.h2.command.dml.Delete used on opensource projects

Example 16 with Delete

use of org.h2.command.dml.Delete in project h2database by h2database.

the class Session method unlockReadLocks.

/**
 * Unlock all read locks. This is done if the transaction isolation mode is
 * READ_COMMITTED.
 */
public void unlockReadLocks() {
    if (database.isMultiVersion()) {
        // MVCC: keep shared locks (insert / update / delete)
        return;
    }
    // locks is modified in the loop
    for (int i = 0; i < locks.size(); i++) {
        Table t = locks.get(i);
        if (!t.isLockedExclusively()) {
            synchronized (database) {
                t.unlock(this);
                locks.remove(i);
            }
            i--;
        }
    }
}

Example 17 with Delete

use of org.h2.command.dml.Delete in project h2database by h2database.

the class LobStorageMap method init.

@Override
public void init() {
    if (init) {
        return;
    }
    init = true;
    Store s = database.getMvStore();
    MVStore mvStore;
    if (s == null) {
        // in-memory database
        mvStore = MVStore.open(null);
    } else {
        mvStore = s.getStore();
    }
    lobMap = mvStore.openMap("lobMap");
    refMap = mvStore.openMap("lobRef");
    dataMap = mvStore.openMap("lobData");
    streamStore = new StreamStore(dataMap);
    // garbage collection of the last blocks
    if (database.isReadOnly()) {
        return;
    }
    if (dataMap.isEmpty()) {
        return;
    }
    // search for the last block
    // (in theory, only the latest lob can have unreferenced blocks,
    // but the latest lob could be a copy of another one, and
    // we don't know that, so we iterate over all lobs)
    long lastUsedKey = -1;
    for (Entry<Long, Object[]> e : lobMap.entrySet()) {
        long lobId = e.getKey();
        Object[] v = e.getValue();
        byte[] id = (byte[]) v[0];
        long max = streamStore.getMaxBlockKey(id);
        // a lob may not have a referenced blocks if data is kept inline
        if (max != -1 && max > lastUsedKey) {
            lastUsedKey = max;
            if (TRACE) {
                trace("lob " + lobId + " lastUsedKey=" + lastUsedKey);
            }
        }
    }
    if (TRACE) {
        trace("lastUsedKey=" + lastUsedKey);
    }
    // delete all blocks that are newer
    while (true) {
        Long last = dataMap.lastKey();
        if (last == null || last <= lastUsedKey) {
            break;
        }
        if (TRACE) {
            trace("gc " + last);
        }
        dataMap.remove(last);
    }
    // don't re-use block ids, except at the very end
    Long last = dataMap.lastKey();
    if (last != null) {
        streamStore.setNextKey(last + 1);
    }
}

Example 18 with Delete

use of org.h2.command.dml.Delete in project h2database by h2database.

the class PageStore method redoDelete.

/**
 * Redo a delete in a table.
 *
 * @param tableId the object id of the table
 * @param key the key of the row to delete
 */
void redoDelete(int tableId, long key) {
    Index index = metaObjects.get(tableId);
    PageDataIndex scan = (PageDataIndex) index;
    Row row = scan.getRowWithKey(key);
    if (row == null || row.getKey() != key) {
        trace.error(null, "Entry not found: " + key + " found instead: " + row + " - ignoring");
        return;
    }
    redo(tableId, row, false);
}

Example 19 with Delete

use of org.h2.command.dml.Delete in project h2database by h2database.

the class UpdatableRow method deleteRow.

/**
 * Delete the given row in the database.
 *
 * @param current the row
 * @throws SQLException if this row has already been deleted
 */
public void deleteRow(Value[] current) throws SQLException {
    StatementBuilder buff = new StatementBuilder("DELETE FROM ");
    appendTableName(buff);
    appendKeyCondition(buff);
    PreparedStatement prep = conn.prepareStatement(buff.toString());
    setKey(prep, 1, current);
    int count = prep.executeUpdate();
    if (count != 1) {
        // the row has already been deleted
        throw DbException.get(ErrorCode.NO_DATA_AVAILABLE);
    }
}

Example 20 with Delete

use of org.h2.command.dml.Delete in project h2database by h2database.

the class Test method main.

public static void main(String... args) throws Exception {
    H2Database db = H2Utils.openOrCreateDatabase("helloWorld.db", MODE_PRIVATE, null);
    log("opened ps=" + db.getPageSize());
    try {
        // db.execSQL("DROP TABLE IF EXISTS test");
        // log("dropped");
        db.execSQL("CREATE TABLE if not exists test(ID INTEGER PRIMARY KEY, NAME VARCHAR)");
        log("created");
        for (int j = 0; j < 10; j++) {
            Cursor c = db.rawQuery("select * from test", new String[0]);
            int count = c.getCount();
            for (int i = 0; i < count; i++) {
                c.move(1);
                c.getInt(0);
                c.getString(1);
            }
            c.close();
        }
        // log("select " + count);
        db.execSQL("delete from test");
        log("delete");
        db.beginTransaction();
        for (int i = 0; i < 1000; i++) {
            db.execSQL("INSERT INTO TEST VALUES(?, 'Hello')", new Object[] { i });
        }
        db.setTransactionSuccessful();
        db.endTransaction();
        log("inserted");
        for (int i = 0; i < 10; i++) {
            Cursor c = db.rawQuery("select * from test where id=?", new String[] { "" + i });
            int count = c.getCount();
            if (count > 0) {
                c.move(1);
                c.getInt(0);
                c.getString(1);
            }
            c.close();
        }
        log("select");
    } finally {
        db.close();
        log("closed");
    }
}