Examples with Value com.wplatform.ddal.value.Value used on opensource projects

Example 36 with Value

use of com.wplatform.ddal.value.Value in project jdbc-shards by wplatform.

the class ConditionInSelect method exportParameters.

@Override
public String exportParameters(TableFilter filter, List<Value> container) {
    Session session = filter.getSession();
    LocalResult rows = query(session);
    if (rows.getRowCount() > 0) {
        StatementBuilder buff = new StatementBuilder();
        buff.append('(').append(left.exportParameters(filter, container)).append(' ');
        if (all) {
            // 由于all代表全部，所以<all表示小于子查询中返回全部值中的最小值；
            // >all表示大于子查询中返回全部值中的最大值。
            buff.append(Comparison.getCompareOperator(compareType)).append(" ALL");
        } else {
            if (compareType == Comparison.EQUAL) {
                buff.append("IN");
            } else {
                // <any可以理解为小于子查询中返回的任意一个值，因此只要小于最大值即可
                // >any可以理解为大于子查询中返回的任意一个值，因此只要大于最小值即可
                buff.append(Comparison.getCompareOperator(compareType)).append(" ANY");
            }
        }
        buff.append("(");
        while (rows.next()) {
            buff.appendExceptFirst(",");
            buff.append("?");
            Value r = rows.currentRow()[0];
            container.add(r);
        }
        buff.append("))");
        return buff.toString();
    } else {
        return "1 = 0";
    }
}

Example 37 with Value

use of com.wplatform.ddal.value.Value in project jdbc-shards by wplatform.

the class Query method prepareOrder.

/**
 * Create a {@link SortOrder} object given the list of {@link SelectOrderBy}
 * objects. The expression list is extended if necessary.
 *
 * @param orderList       a list of {@link SelectOrderBy} elements
 * @param expressionCount the number of columns in the query
 * @return the {@link SortOrder} object
 */
public SortOrder prepareOrder(ArrayList<SelectOrderBy> orderList, int expressionCount) {
    int size = orderList.size();
    int[] index = new int[size];
    int[] sortType = new int[size];
    for (int i = 0; i < size; i++) {
        SelectOrderBy o = orderList.get(i);
        int idx;
        boolean reverse = false;
        Expression expr = o.columnIndexExpr;
        Value v = expr.getValue(null);
        if (v == ValueNull.INSTANCE) {
            // parameter not yet set - order by first column
            idx = 0;
        } else {
            idx = v.getInt();
            if (idx < 0) {
                reverse = true;
                idx = -idx;
            }
            idx -= 1;
            if (idx < 0 || idx >= expressionCount) {
                throw DbException.get(ErrorCode.ORDER_BY_NOT_IN_RESULT, "" + (idx + 1));
            }
        }
        index[i] = idx;
        boolean desc = o.descending;
        if (reverse) {
            desc = !desc;
        }
        int type = desc ? SortOrder.DESCENDING : SortOrder.ASCENDING;
        if (o.nullsFirst) {
            type += SortOrder.NULLS_FIRST;
        } else if (o.nullsLast) {
            type += SortOrder.NULLS_LAST;
        }
        sortType[i] = type;
    }
    return new SortOrder(session.getDatabase(), index, sortType, orderList);
}

Example 38 with Value

use of com.wplatform.ddal.value.Value in project jdbc-shards by wplatform.

the class Query method query.

/**
 * Execute the query, writing the result to the target result.
 *
 * @param limit  the maximum number of rows to return
 * @param target the target result (null will return the result)
 * @return the result set (if the target is not set).
 */
public LocalResult query(int limit, ResultTarget target) {
    if (noCache) {
        return queryWithoutCache(limit, target);
    }
    Value[] params = getParameterValues();
    if (isEverything(ExpressionVisitor.DETERMINISTIC_VISITOR)) {
        if (lastResult != null && !lastResult.isClosed() && limit == lastLimit) {
            if (sameResultAsLast(session, params, lastParameters)) {
                lastResult = lastResult.createShallowCopy(session);
                if (lastResult != null) {
                    lastResult.reset();
                    return lastResult;
                }
            }
        }
    }
    lastParameters = params;
    closeLastResult();
    LocalResult r = queryWithoutCache(limit, target);
    lastResult = r;
    lastLimit = limit;
    return r;
}

Example 39 with Value

use of com.wplatform.ddal.value.Value in project jdbc-shards by wplatform.

the class JdbcConnection method createClob.

/**
 * Create a new empty Clob object.
 *
 * @return the object
 */
@Override
public Clob createClob() throws SQLException {
    try {
        int id = getNextId(TraceObject.CLOB);
        debugCodeAssign("Clob", TraceObject.CLOB, id, "createClob()");
        checkClosedForWrite();
        try {
            Value v = ValueLobDb.createTempClob(new InputStreamReader(new ByteArrayInputStream(Utils.EMPTY_BYTES)), 0);
            session.addTemporaryLob(v);
            return new JdbcClob(this, v, id);
        } finally {
            afterWriting();
        }
    } catch (Exception e) {
        throw logAndConvert(e);
    }
}

Example 40 with Value

use of com.wplatform.ddal.value.Value in project jdbc-shards by wplatform.

the class SelectUnion method queryWithoutCache.

@Override
protected LocalResult 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 == 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();
    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);
    }
    LocalResult l = left.query(0);
    LocalResult 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);
                    }
                }
                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;
}