Examples with PageException com.github.pagehelper.PageException used on opensource projects

Example 6 with PageException

use of com.github.pagehelper.PageException in project Mybatis-PageHelper by pagehelper.

the class PageAutoDialect method getDialect.

/**
     * 根据 jdbcUrl 获取数据库方言
     *
     * @param ms
     * @return
     */
private AbstractHelperDialect getDialect(MappedStatement ms) {
    //改为对dataSource做缓存
    DataSource dataSource = ms.getConfiguration().getEnvironment().getDataSource();
    String url = getUrl(dataSource);
    if (urlDialectMap.containsKey(url)) {
        return urlDialectMap.get(url);
    }
    try {
        lock.lock();
        if (urlDialectMap.containsKey(url)) {
            return urlDialectMap.get(url);
        }
        if (StringUtil.isEmpty(url)) {
            throw new PageException("无法自动获取jdbcUrl，请在分页插件中配置dialect参数!");
        }
        String dialectStr = fromJdbcUrl(url);
        if (dialectStr == null) {
            throw new PageException("无法自动获取数据库类型，请通过 helperDialect 参数指定!");
        }
        AbstractHelperDialect dialect = initDialect(dialectStr, properties);
        urlDialectMap.put(url, dialect);
        return dialect;
    } finally {
        lock.unlock();
    }
}

Example 7 with PageException

use of com.github.pagehelper.PageException in project Mybatis-PageHelper by pagehelper.

the class SqlServerParser method getPageSelect.

/**
 * 获取一个外层包装的TOP查询
 *
 * @param select
 * @return
 */
protected Select getPageSelect(Select select) {
    SelectBody selectBody = select.getSelectBody();
    if (selectBody instanceof SetOperationList) {
        selectBody = wrapSetOperationList((SetOperationList) selectBody);
    }
    // 这里的selectBody一定是PlainSelect
    if (((PlainSelect) selectBody).getTop() != null) {
        throw new PageException("被分页的语句已经包含了Top，不能再通过分页插件进行分页查询!");
    }
    // 获取查询列
    List<SelectItem> selectItems = getSelectItems((PlainSelect) selectBody);
    // 对一层的SQL增加ROW_NUMBER()
    List<SelectItem> autoItems = new ArrayList<SelectItem>();
    SelectItem orderByColumn = addRowNumber((PlainSelect) selectBody, autoItems);
    // 加入自动生成列
    ((PlainSelect) selectBody).addSelectItems(autoItems.toArray(new SelectItem[autoItems.size()]));
    // 处理子语句中的order by
    processSelectBody(selectBody, 0);
    // 中层子查询
    PlainSelect innerSelectBody = new PlainSelect();
    // PAGE_ROW_NUMBER
    innerSelectBody.addSelectItems(orderByColumn);
    innerSelectBody.addSelectItems(selectItems.toArray(new SelectItem[selectItems.size()]));
    // 将原始查询作为内层子查询
    SubSelect fromInnerItem = new SubSelect();
    fromInnerItem.setSelectBody(selectBody);
    fromInnerItem.setAlias(PAGE_TABLE_ALIAS);
    innerSelectBody.setFromItem(fromInnerItem);
    // 新建一个select
    Select newSelect = new Select();
    PlainSelect newSelectBody = new PlainSelect();
    // 设置top
    Top top = new Top();
    top.setExpression(new LongValue(Long.MAX_VALUE));
    newSelectBody.setTop(top);
    // 设置order by
    List<OrderByElement> orderByElements = new ArrayList<OrderByElement>();
    OrderByElement orderByElement = new OrderByElement();
    orderByElement.setExpression(PAGE_ROW_NUMBER_COLUMN);
    orderByElements.add(orderByElement);
    newSelectBody.setOrderByElements(orderByElements);
    // 设置where
    GreaterThan greaterThan = new GreaterThan();
    greaterThan.setLeftExpression(PAGE_ROW_NUMBER_COLUMN);
    greaterThan.setRightExpression(new LongValue(Long.MIN_VALUE));
    newSelectBody.setWhere(greaterThan);
    // 设置selectItems
    newSelectBody.setSelectItems(selectItems);
    // 设置fromIterm
    SubSelect fromItem = new SubSelect();
    // 中层子查询
    fromItem.setSelectBody(innerSelectBody);
    fromItem.setAlias(PAGE_TABLE_ALIAS);
    newSelectBody.setFromItem(fromItem);
    newSelect.setSelectBody(newSelectBody);
    if (isNotEmptyList(select.getWithItemsList())) {
        newSelect.setWithItemsList(select.getWithItemsList());
    }
    return newSelect;
}

Example 8 with PageException

use of com.github.pagehelper.PageException in project Mybatis-PageHelper by pagehelper.

the class SqlServerParser method wrapSetOperationList.

/**
 * 包装SetOperationList
 *
 * @param setOperationList
 * @return
 */
protected SelectBody wrapSetOperationList(SetOperationList setOperationList) {
    // 获取最后一个plainSelect
    SelectBody setSelectBody = setOperationList.getSelects().get(setOperationList.getSelects().size() - 1);
    if (!(setSelectBody instanceof PlainSelect)) {
        throw new PageException("目前无法处理该SQL，您可以将该SQL发送给abel533@gmail.com协助作者解决!");
    }
    PlainSelect plainSelect = (PlainSelect) setSelectBody;
    PlainSelect selectBody = new PlainSelect();
    List<SelectItem> selectItems = getSelectItems(plainSelect);
    selectBody.setSelectItems(selectItems);
    // 设置fromIterm
    SubSelect fromItem = new SubSelect();
    fromItem.setSelectBody(setOperationList);
    fromItem.setAlias(new Alias(WRAP_TABLE));
    selectBody.setFromItem(fromItem);
    // order by
    if (isNotEmptyList(plainSelect.getOrderByElements())) {
        selectBody.setOrderByElements(plainSelect.getOrderByElements());
        plainSelect.setOrderByElements(null);
    }
    return selectBody;
}

Example 9 with PageException

use of com.github.pagehelper.PageException in project Mybatis-PageHelper by pagehelper.

the class OrderByParser method converToOrderBySql.

/**
 * convert to order by sql
 *
 * @param sql
 * @param orderBy
 * @return
 */
public static String converToOrderBySql(String sql, String orderBy) {
    // 解析SQL
    Statement stmt = null;
    try {
        stmt = CCJSqlParserUtil.parse(sql);
        Select select = (Select) stmt;
        SelectBody selectBody = select.getSelectBody();
        // 处理body-去最外层order by
        List<OrderByElement> orderByElements = extraOrderBy(selectBody);
        String defaultOrderBy = PlainSelect.orderByToString(orderByElements);
        if (defaultOrderBy.indexOf('?') != -1) {
            throw new PageException("原SQL[" + sql + "]中的order by包含参数，因此不能使用OrderBy插件进行修改!");
        }
        // 新的sql
        sql = select.toString();
    } catch (Throwable e) {
        log.warn("处理排序失败: " + e + "，降级为直接拼接 order by 参数");
    }
    return sql + " order by " + orderBy;
}