Examples with LocalResult org.h2.result.LocalResult used on opensource projects

Example 11 with LocalResult

use of org.h2.result.LocalResult in project h2database by h2database.

the class SelectUnion method queryWithoutCache.

@Override
protected ResultInterface queryWithoutCache(int maxRows, ResultTarget target) {
    if (maxRows != 0) {
        // maxRows is set (maxRows 0 means no limit)
        int l;
        if (limitExpr == null) {
            l = -1;
        } else {
            Value v = limitExpr.getValue(session);
            l = v == ValueNull.INSTANCE ? -1 : v.getInt();
        }
        if (l < 0) {
            // for limitExpr, 0 means no rows, and -1 means no limit
            l = maxRows;
        } else {
            l = Math.min(l, maxRows);
        }
        limitExpr = ValueExpression.get(ValueInt.get(l));
    }
    if (session.getDatabase().getSettings().optimizeInsertFromSelect) {
        if (unionType == UnionType.UNION_ALL && target != null) {
            if (sort == null && !distinct && maxRows == 0 && offsetExpr == null && limitExpr == null) {
                left.query(0, target);
                right.query(0, target);
                return null;
            }
        }
    }
    int columnCount = left.getColumnCount();
    if (session.isLazyQueryExecution() && unionType == UnionType.UNION_ALL && !distinct && sort == null && !randomAccessResult && !isForUpdate && offsetExpr == null && isReadOnly()) {
        int limit = -1;
        if (limitExpr != null) {
            Value v = limitExpr.getValue(session);
            if (v != ValueNull.INSTANCE) {
                limit = v.getInt();
            }
        }
        // limit 0 means no rows
        if (limit != 0) {
            LazyResultUnion lazyResult = new LazyResultUnion(expressionArray, columnCount);
            if (limit > 0) {
                lazyResult.setLimit(limit);
            }
            return lazyResult;
        }
    }
    LocalResult result = new LocalResult(session, expressionArray, columnCount);
    if (sort != null) {
        result.setSortOrder(sort);
    }
    if (distinct) {
        left.setDistinct(true);
        right.setDistinct(true);
        result.setDistinct();
    }
    if (randomAccessResult) {
        result.setRandomAccess();
    }
    switch(unionType) {
        case UNION:
        case EXCEPT:
            left.setDistinct(true);
            right.setDistinct(true);
            result.setDistinct();
            break;
        case UNION_ALL:
            break;
        case INTERSECT:
            left.setDistinct(true);
            right.setDistinct(true);
            break;
        default:
            DbException.throwInternalError("type=" + unionType);
    }
    ResultInterface l = left.query(0);
    ResultInterface r = right.query(0);
    l.reset();
    r.reset();
    switch(unionType) {
        case UNION_ALL:
        case UNION:
            {
                while (l.next()) {
                    result.addRow(convert(l.currentRow(), columnCount));
                }
                while (r.next()) {
                    result.addRow(convert(r.currentRow(), columnCount));
                }
                break;
            }
        case EXCEPT:
            {
                while (l.next()) {
                    result.addRow(convert(l.currentRow(), columnCount));
                }
                while (r.next()) {
                    result.removeDistinct(convert(r.currentRow(), columnCount));
                }
                break;
            }
        case INTERSECT:
            {
                LocalResult temp = new LocalResult(session, expressionArray, columnCount);
                temp.setDistinct();
                temp.setRandomAccess();
                while (l.next()) {
                    temp.addRow(convert(l.currentRow(), columnCount));
                }
                while (r.next()) {
                    Value[] values = convert(r.currentRow(), columnCount);
                    if (temp.containsDistinct(values)) {
                        result.addRow(values);
                    }
                }
                temp.close();
                break;
            }
        default:
            DbException.throwInternalError("type=" + unionType);
    }
    if (offsetExpr != null) {
        result.setOffset(offsetExpr.getValue(session).getInt());
    }
    if (limitExpr != null) {
        Value v = limitExpr.getValue(session);
        if (v != ValueNull.INSTANCE) {
            result.setLimit(v.getInt());
        }
    }
    l.close();
    r.close();
    result.done();
    if (target != null) {
        while (result.next()) {
            target.addRow(result.currentRow());
        }
        result.close();
        return null;
    }
    return result;
}

Example 12 with LocalResult

use of org.h2.result.LocalResult in project h2database by h2database.

the class Call method query.

@Override
public ResultInterface query(int maxrows) {
    setCurrentRowNumber(1);
    Value v = expression.getValue(session);
    if (isResultSet) {
        v = v.convertTo(Value.RESULT_SET);
        ResultSet rs = v.getResultSet();
        return LocalResult.read(session, rs, maxrows);
    }
    LocalResult result = new LocalResult(session, expressions, 1);
    Value[] row = { v };
    result.addRow(row);
    result.done();
    return result;
}

Example 13 with LocalResult

use of org.h2.result.LocalResult in project h2database by h2database.

the class FunctionTable method getResult.

/**
 * Read the result from the function. This method buffers the result in a
 * temporary file.
 *
 * @param session the session
 * @return the result
 */
public ResultInterface getResult(Session session) {
    ValueResultSet v = getValueResultSet(session);
    if (v == null) {
        return null;
    }
    if (cachedResult != null && cachedValue == v) {
        cachedResult.reset();
        return cachedResult;
    }
    LocalResult result = LocalResult.read(session, v.getResultSet(), 0);
    if (function.isDeterministic()) {
        cachedResult = result;
        cachedValue = v;
    }
    return result;
}

Example 14 with LocalResult

use of org.h2.result.LocalResult in project h2database by h2database.

the class TableFunction method getSimpleResultSet.

private static SimpleResultSet getSimpleResultSet(LocalResult rs, int maxrows) {
    int columnCount = rs.getVisibleColumnCount();
    SimpleResultSet simple = new SimpleResultSet();
    simple.setAutoClose(false);
    for (int i = 0; i < columnCount; i++) {
        String name = rs.getColumnName(i);
        DataType dataType = DataType.getDataType(rs.getColumnType(i));
        int sqlType = dataType.sqlType;
        String sqlTypeName = dataType.name;
        int precision = MathUtils.convertLongToInt(rs.getColumnPrecision(i));
        int scale = rs.getColumnScale(i);
        simple.addColumn(name, sqlType, sqlTypeName, precision, scale);
    }
    rs.reset();
    for (int i = 0; i < maxrows && rs.next(); i++) {
        Object[] list = new Object[columnCount];
        for (int j = 0; j < columnCount; j++) {
            list[j] = rs.currentRow()[j].getObject();
        }
        simple.addRow(list);
    }
    return simple;
}