Examples with CursorActivation org.apache.derby.iapi.sql.execute.CursorActivation used on opensource projects

Example 1 with CursorActivation

use of org.apache.derby.iapi.sql.execute.CursorActivation in project derby by apache.

the class EmbedResultSet method updateRow.

/**
 * JDBC 2.0
 *
 * Update the underlying database with the new contents of the
 * current row.  Cannot be called when on the insert row.
 *
 * @exception SQLException if a database-access error occurs, or
 * if called when on the insert row
 */
public void updateRow() throws SQLException {
    synchronized (getConnectionSynchronization()) {
        checksBeforeUpdateOrDelete("updateRow", -1);
        // Check that the cursor is not positioned on insertRow
        checkNotOnInsertRow();
        setupContextStack();
        LanguageConnectionContext lcc = getLanguageConnectionContext(getEmbedConnection());
        StatementContext statementContext = null;
        try {
            if (// nothing got updated on this row
            currentRowHasBeenUpdated == false)
                // nothing to do since no updates were made to this row
                return;
            // now construct the update where current of sql
            boolean foundOneColumnAlready = false;
            StringBuffer updateWhereCurrentOfSQL = new StringBuffer("UPDATE ");
            CursorActivation activation = lcc.lookupCursorActivation(getCursorName());
            ExecCursorTableReference targetTable = activation.getPreparedStatement().getTargetTable();
            // got the underlying (schema.)table name
            updateWhereCurrentOfSQL.append(getFullBaseTableName(targetTable));
            updateWhereCurrentOfSQL.append(" SET ");
            ResultDescription rd = theResults.getResultDescription();
            for (int i = 1; i <= rd.getColumnCount(); i++) {
                // in this for loop we are constructing columnname=?,... part of the update sql
                if (columnGotUpdated[i - 1]) {
                    // if the column got updated, do following
                    if (foundOneColumnAlready)
                        updateWhereCurrentOfSQL.append(",");
                    // using quotes around the column name to preserve case sensitivity
                    updateWhereCurrentOfSQL.append(IdUtil.normalToDelimited(rd.getColumnDescriptor(i).getName()) + "=?");
                    foundOneColumnAlready = true;
                }
            }
            // using quotes around the cursor name to preserve case sensitivity
            updateWhereCurrentOfSQL.append(" WHERE CURRENT OF " + IdUtil.normalToDelimited(getCursorName()));
            StatementContext currSC = lcc.getStatementContext();
            Activation parentAct = null;
            if (currSC != null) {
                parentAct = currSC.getActivation();
            }
            // Context used for preparing, don't set any timeout (use 0)
            statementContext = lcc.pushStatementContext(isAtomic, false, updateWhereCurrentOfSQL.toString(), null, false, 0L);
            // A priori, the new statement context inherits the activation of
            // the existing statementContext, so that that activation ends up
            // as parent of the new activation 'act' created below, which will
            // be the activation of the pushed statement context.
            statementContext.setActivation(parentAct);
            org.apache.derby.iapi.sql.PreparedStatement ps = lcc.prepareInternalStatement(updateWhereCurrentOfSQL.toString());
            Activation act = ps.getActivation(lcc, false);
            statementContext.setActivation(act);
            // in this for loop we are assigning values for parameters in sql constructed earlier with columnname=?,...
            for (int i = 1, paramPosition = 0; i <= rd.getColumnCount(); i++) {
                if (// if the column got updated, do following
                columnGotUpdated[i - 1])
                    act.getParameterValueSet().getParameterForSet(paramPosition++).setValue(updateRow.getColumn(i));
            }
            // Don't set any timeout when updating rows (use 0)
            // Execute the update where current of sql.
            org.apache.derby.iapi.sql.ResultSet rs = ps.executeSubStatement(activation, act, true, 0L);
            SQLWarning w = act.getWarnings();
            if (w != null) {
                addWarning(w);
            }
            act.close();
            // For forward only resultsets, after a update, the ResultSet will be positioned right before the next row.
            if (getType() == TYPE_FORWARD_ONLY) {
                currentRow = null;
            } else {
                movePosition(RELATIVE, 0, "relative");
            }
            lcc.popStatementContext(statementContext, null);
            InterruptStatus.restoreIntrFlagIfSeen(lcc);
        } catch (Throwable t) {
            throw closeOnTransactionError(t);
        } finally {
            if (statementContext != null)
                lcc.popStatementContext(statementContext, null);
            restoreContextStack();
            initializeUpdateRowModifiers();
        }
    }
}

Example 2 with CursorActivation

use of org.apache.derby.iapi.sql.execute.CursorActivation in project derby by apache.

the class EmbedResultSet method insertRow.

/**
 * JDBC 2.0
 *
 * Insert the contents of the insert row into the result set and the
 * database. Must be on the insert row when this method is called.
 *
 * @exception SQLException
 *                if a database-access error occurs, if called when not on
 *                the insert row, or if all non-nullable columns in the
 *                insert row have not been given a value
 */
public void insertRow() throws SQLException {
    synchronized (getConnectionSynchronization()) {
        checksBeforeInsert();
        setupContextStack();
        LanguageConnectionContext lcc = getLanguageConnectionContext(getEmbedConnection());
        StatementContext statementContext = null;
        try {
            /*
                 * construct the insert statement
                 *
                 * If no values have been supplied for a column, it will be set 
                 * to the column's default value, if any. 
                 * If no default value had been defined, the default value of a 
                 * nullable column is set to NULL.
                 */
            boolean foundOneColumnAlready = false;
            StringBuffer insertSQL = new StringBuffer("INSERT INTO ");
            StringBuffer valuesSQL = new StringBuffer("VALUES (");
            CursorActivation activation = lcc.lookupCursorActivation(getCursorName());
            ExecCursorTableReference targetTable = activation.getPreparedStatement().getTargetTable();
            // got the underlying (schema.)table name
            insertSQL.append(getFullBaseTableName(targetTable));
            ResultDescription rd = theResults.getResultDescription();
            insertSQL.append(" (");
            // and values (?) ,... part of the insert sql
            for (int i = 1; i <= rd.getColumnCount(); i++) {
                if (foundOneColumnAlready) {
                    insertSQL.append(",");
                    valuesSQL.append(",");
                }
                // using quotes around the column name
                // to preserve case sensitivity
                insertSQL.append(IdUtil.normalToDelimited(rd.getColumnDescriptor(i).getName()));
                if (columnGotUpdated[i - 1]) {
                    valuesSQL.append("?");
                } else {
                    valuesSQL.append("DEFAULT");
                }
                foundOneColumnAlready = true;
            }
            insertSQL.append(") ");
            valuesSQL.append(") ");
            insertSQL.append(valuesSQL);
            StatementContext currSC = lcc.getStatementContext();
            Activation parentAct = null;
            if (currSC != null) {
                parentAct = currSC.getActivation();
            }
            // Context used for preparing, don't set any timeout (use 0)
            statementContext = lcc.pushStatementContext(isAtomic, false, insertSQL.toString(), null, false, 0L);
            // A priori, the new statement context inherits the activation
            // of the existing statementContext, so that that activation
            // ends up as parent of the new activation 'act' created below,
            // which will be the activation of the pushed statement
            // context.
            statementContext.setActivation(parentAct);
            org.apache.derby.iapi.sql.PreparedStatement ps = lcc.prepareInternalStatement(insertSQL.toString());
            Activation act = ps.getActivation(lcc, false);
            statementContext.setActivation(act);
            // in sql constructed earlier VALUES (?, ..)
            for (int i = 1, paramPosition = 0; i <= rd.getColumnCount(); i++) {
                // if the column got updated, do following
                if (columnGotUpdated[i - 1]) {
                    act.getParameterValueSet().getParameterForSet(paramPosition++).setValue(updateRow.getColumn(i));
                }
            }
            // Don't see any timeout when inserting rows (use 0)
            // execute the insert
            org.apache.derby.iapi.sql.ResultSet rs = ps.executeSubStatement(activation, act, true, 0L);
            act.close();
            lcc.popStatementContext(statementContext, null);
            InterruptStatus.restoreIntrFlagIfSeen(lcc);
        } catch (Throwable t) {
            throw closeOnTransactionError(t);
        } finally {
            if (statementContext != null)
                lcc.popStatementContext(statementContext, null);
            restoreContextStack();
        }
    }
}

Example 3 with CursorActivation

use of org.apache.derby.iapi.sql.execute.CursorActivation in project derby by apache.

the class EmbedResultSet method deleteRow.

/**
 * JDBC 2.0
 *
 * Delete the current row from the result set and the underlying
 * database.  Cannot be called when on the insert row.
 *
 * @exception SQLException if a database-access error occurs, or if
 * called when on the insert row.
 */
public void deleteRow() throws SQLException {
    synchronized (getConnectionSynchronization()) {
        checksBeforeUpdateOrDelete("deleteRow", -1);
        // Check that the cursor is not positioned on insertRow
        checkNotOnInsertRow();
        setupContextStack();
        LanguageConnectionContext lcc = getLanguageConnectionContext(getEmbedConnection());
        StatementContext statementContext = null;
        // now construct the delete where current of sql
        try {
            StringBuffer deleteWhereCurrentOfSQL = new StringBuffer("DELETE FROM ");
            CursorActivation activation = lcc.lookupCursorActivation(getCursorName());
            // get the underlying (schema.)table name
            deleteWhereCurrentOfSQL.append(getFullBaseTableName(activation.getPreparedStatement().getTargetTable()));
            // using quotes around the cursor name to preserve case sensitivity
            deleteWhereCurrentOfSQL.append(" WHERE CURRENT OF " + IdUtil.normalToDelimited(getCursorName()));
            StatementContext currSC = lcc.getStatementContext();
            Activation parentAct = null;
            if (currSC != null) {
                parentAct = currSC.getActivation();
            }
            // Context used for preparing, don't set any timeout (use 0)
            statementContext = lcc.pushStatementContext(isAtomic, false, deleteWhereCurrentOfSQL.toString(), null, false, 0L);
            // A priori, the new statement context inherits the activation
            // of the existing statementContext, so that that activation
            // ends up as parent of the new activation 'act' created below,
            // which will be the activation of the pushed statement
            // context.
            statementContext.setActivation(parentAct);
            org.apache.derby.iapi.sql.PreparedStatement ps = lcc.prepareInternalStatement(deleteWhereCurrentOfSQL.toString());
            // Get activation, so that we can get the warning from it
            Activation act = ps.getActivation(lcc, false);
            statementContext.setActivation(act);
            // Don't set any timeout when deleting rows (use 0)
            // execute delete where current of sql
            org.apache.derby.iapi.sql.ResultSet rs = ps.executeSubStatement(activation, act, true, 0L);
            SQLWarning w = act.getWarnings();
            if (w != null) {
                addWarning(w);
            }
            act.close();
            // After a delete, the ResultSet will be positioned right before
            // the next row.
            currentRow = null;
            lcc.popStatementContext(statementContext, null);
            InterruptStatus.restoreIntrFlagIfSeen(lcc);
        } catch (Throwable t) {
            throw closeOnTransactionError(t);
        } finally {
            if (statementContext != null)
                lcc.popStatementContext(statementContext, null);
            restoreContextStack();
            initializeUpdateRowModifiers();
        }
    }
}

Example 4 with CursorActivation

use of org.apache.derby.iapi.sql.execute.CursorActivation in project derby by apache.

the class GenericLanguageConnectionContext method lookupCursorActivation.

/**
 * See if a given cursor is available for use.
 * if so return its activation. Returns null if not found.
 * For use in execution.
 *
 * @return the activation for the given cursor, null
 *  if none was found.
 */
public CursorActivation lookupCursorActivation(String cursorName) {
    int size = acts.size();
    if (size > 0) {
        int cursorHash = cursorName.hashCode();
        for (int i = 0; i < size; i++) {
            Activation a = acts.get(i);
            if (!a.isInUse()) {
                continue;
            }
            String executingCursorName = a.getCursorName();
            // two names actually are equal.
            if (executingCursorName == null || executingCursorName.hashCode() != cursorHash) {
                continue;
            }
            if (cursorName.equals(executingCursorName)) {
                ResultSet rs = a.getResultSet();
                if (rs == null)
                    continue;
                // if the result set is closed, the the cursor doesn't exist
                if (rs.isClosed()) {
                    continue;
                }
                return (CursorActivation) a;
            }
        }
    }
    return null;
}

Example 5 with CursorActivation

use of org.apache.derby.iapi.sql.execute.CursorActivation in project derby by apache.

the class GenericLanguageConnectionContext method verifyAllHeldResultSetsAreClosed.

/**
 * Verify that there are no activations with open held result sets.
 *
 * @return boolean  Found no open (held) resultsets.
 *
 * @exception StandardException thrown on failure
 */
/* This gets used in case of hold cursors. If there are any hold cursors open
     * then user can't change the isolation level without closing them. At the
     * execution time, set transaction isolation level calls this method before
     * changing the isolation level.
     */
public boolean verifyAllHeldResultSetsAreClosed() throws StandardException {
    boolean seenOpenResultSets = false;
    /* For every activation */
    for (int i = acts.size() - 1; i >= 0; i--) {
        Activation a = acts.get(i);
        if (SanityManager.DEBUG) {
            SanityManager.ASSERT(a instanceof CursorActivation, "a is not a CursorActivation");
        }
        if (!a.isInUse()) {
            continue;
        }
        if (!a.getResultSetHoldability()) {
            continue;
        }
        ResultSet rs = ((CursorActivation) a).getResultSet();
        /* is there an open result set? */
        if ((rs != null) && !rs.isClosed() && rs.returnsRows()) {
            seenOpenResultSets = true;
            break;
        }
    }
    if (!seenOpenResultSets)
        return (true);
    // There may be open ResultSet's that are yet to be garbage collected
    // let's try and force these out rather than throw an error
    System.gc();
    System.runFinalization();
    /* For every activation */
    for (int i = acts.size() - 1; i >= 0; i--) {
        Activation a = acts.get(i);
        if (SanityManager.DEBUG) {
            SanityManager.ASSERT(a instanceof CursorActivation, "a is not a CursorActivation");
        }
        if (!a.isInUse()) {
            continue;
        }
        if (!a.getResultSetHoldability()) {
            continue;
        }
        ResultSet rs = ((CursorActivation) a).getResultSet();
        /* is there an open held result set? */
        if ((rs != null) && !rs.isClosed() && rs.returnsRows()) {
            return (false);
        }
    }
    return (true);
}