spring+hibernate+struts1分页问题

Question

我在使用Oracle9iDialect进行分页时发现在页面超过20页有时候出现每一页显示和前一页内容一样，后来发现数据库用的是11g而hibernate方言用的是Oracle9iDialect，把Oracle9iDialect换成OracleDialect就没有问题了，求解

Answer 1

分页sql是通过dialect生成的

OracleDialect
[code="java"] public String getLimitString(String sql, boolean hasOffset) {

    sql = sql.trim();
    boolean isForUpdate = false;
    if ( sql.toLowerCase().endsWith(" for update") ) {
        sql = sql.substring( 0, sql.length()-11 );
        isForUpdate = true;
    }

    StringBuffer pagingSelect = new StringBuffer( sql.length()+100 );
    if (hasOffset) {
        pagingSelect.append("select * from ( select row_.*, rownum rownum_ from ( ");
    }
    else {
        pagingSelect.append("select * from ( ");
    }
    pagingSelect.append(sql);
    if (hasOffset) {
        pagingSelect.append(" ) row_ ) where rownum_ <= ? and rownum_ > ?");
    }
    else {
        pagingSelect.append(" ) where rownum <= ?");
    }

    if ( isForUpdate ) {
        pagingSelect.append( " for update" );
    }

    return pagingSelect.toString();
}[/code]

Oracle9iDialect
[code="java"] public String getLimitString(String sql, boolean hasOffset) {

    sql = sql.trim();
    boolean isForUpdate = false;
    if ( sql.toLowerCase().endsWith(" for update") ) {
        sql = sql.substring( 0, sql.length()-11 );
        isForUpdate = true;
    }

    StringBuffer pagingSelect = new StringBuffer( sql.length()+100 );
    if (hasOffset) {
        pagingSelect.append("select * from ( select row_.*, rownum rownum_ from ( ");
    }
    else {
        pagingSelect.append("select * from ( ");
    }
    pagingSelect.append(sql);
    if (hasOffset) {
        pagingSelect.append(" ) row_ where rownum <= ?) where rownum_ > ?");
    }
    else {
        pagingSelect.append(" ) where rownum <= ?");
    }

    if ( isForUpdate ) {
        pagingSelect.append( " for update" );
    }

    return pagingSelect.toString();
}

[/code]

唯一不同点：

    if (hasOffset) {
        pagingSelect.append(" ) row_ [color=red])[/color] where rownum_ <= ? and rownum_ > ?");
    }

红色部分 9i不带