关于JDBC数据分页跨数据库小结.doc

关于JDBC数据分页跨数据库小结一、 关于数据连接connection如何区分数据库类型/ 获取数据生产商名称String databaseProductName =conn.getMetaData().getDatabaseProductName();/ 获取数据库版本号String productVersion = conn.getMetaData().getDatabaseProductVersion();测试结果：Oracle/databaseProductName :Oracle/productVersion :Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production/With the Partitioning, OLAP and Data Mining optionsMySQL/databaseProductName :MySQL/productVersion :5.0.84-community-ntMicrosoft SQL Server2000/databaseProductName :Microsoft SQL Server/productVersion :8.00.2039Microsoft SQL Server2005/databaseProductName :Microsoft SQL Server/productVersion : 9.00.1399ACCESS/databaseProductName :ACCESS/productVersion :04.00.0000二、 ORACLE 数据分页方案 采用ORACLE rownum关键字分页1. SQL语句：select * from (select t.*,rownum as rn from (select * from table) t where rownum endrow;2. 生成分页SQL代码：/* * Oracle数据库分页专用 * param sql * param page * return String * see 测试通过 */private static String wrapPage4Oracle(String sql, Page page) int startRow = (page.getPageNo() - 1) * page.getPageSize();int endRow = startRow + page.getPageSize();String osql = select * from (select t.*,rownum as rn from ( + sql+ ) t where rownum + startRow;return osql;三、 MYSQL数据库分页方案采用 limit 关键字1. SQL语句：select trty.* from (select * from table) trty limit startrow ,endrow2. 生成分页SQL代码：/* * MySql数据库分页专用 * param sql * param page * return String * see 未测试 */private static String wrapPage4MySql(String sql, Page page) int startRow = (page.getPageNo() - 1) * page.getPageSize();int endRow = startRow + page.getPageSize();StringBuffer msql = new StringBuffer();msql.append(select trty.* from ();msql.append(sql).append() trty limit );msql.append(startRow).append(,).append(endRow);return msql.toString();四、 ACCESS 数据库分页方案采用rs.absolute()1. 考虑到ACCESS数据库涉及到的数据量比较小，采用全部查找出来进行分页的方案代码：/* * ACCESS数据库分页专用 * param conn * param sql * param page * return List * throws Exception * see 未测试 缺陷查出所有数据进行分页 */private static ListMap wrapPage4ACCESS(Connection conn, String sql, Page page) throws Exception/ 返回值ListMap rows = new ArrayListMap();int startRow = (page.getPageNo() - 1) * page.getPageSize(); int endRow = page.getPageNo()* page.getPageSize(); Statement statement = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY);ResultSet rs = statement.executeQuery(sql);/ 查询范围超过，返回空rowsrs.last();int rownum = rs.getRow();if( (startRow+1) rownum)return rows;/ 判断分页总数是否超过实际数量int startnum = startRow + 1;int endnum = endRow + 1;if(rownum endnum)endnum = rownum;/ 定位到当前页rs.absolute(startnum);while(startnum (SELECTMAX(id)FROM(SELECTTOP20idFROMTestTableORDERBYid)AST)ORDERBYID3. 方案一和二本质一样，但是方案二的效率比较高。对于复杂的SQL不能采用此中分页方式，除非有逻辑严谨的拆解SQL语句的程序。4. 方案三采用存储过程分页，在JAVA程序中调用存储过程。1) 存储过程代码如下IFNOTEXISTS(SELECT*FROMdbo.sysobjectsWHEREid=OBJECT_ID(Ndbo.Pr_QueryByPage)ANDOBJECTPROPERTY(id,NIsProcedure)=1) BEGIN EXECdbo.sp_executesqlstatement=Ncreateproceduredbo.Pr_QueryByPage sqlstrnvarchar(4000),-查询sql currentpageint,-第页记录条数 pagesizeint-每页显示记录 as setnocounton declareP1int,-P1是游标的ID rowcountint execsp_cursoropenP1output,sqlstr,scrollopt=1,ccopt=1,rowcount=rowcountoutput selectceiling(1.0*rowcount/pagesize)asTotalPage,rowcountas RowCount setcurrentpage=(currentpage-1)*pagesize+1 execsp_cursorfetchP1,16,currentpage,pagesize execsp_cursorcloseP1 setnocountoff END GO2) 代码调用/* * Microsoft SQL Server 2000分页专用 * * param conn * param sql * param page * return * throws Exception * see 测试通过 */private static ListMap wrapPage4SQLServer2000(Connection conn, String sql, Page page) throws Exception ListMap rows = new ArrayListMap();int pageno = page.getPageNo();int pagsize = page.getPageSize();/ 调用存储过程分页CallableStatement cs = conn.prepareCall(call Pr_QueryByPage(?,?,?);/ 设置存储过程参数cs.setString(1, sql);cs.setInt(2, pageno);cs.setInt(3, pagsize);cs.execute();boolean hasResultSet = cs.execute();if (hasResultSet) ResultSet rs = null;/* 跳过第一个结果集 */rs = cs.getResultSet();/* 第二个结果集为查询分页数据 */if (cs.getMoreResults() rs = cs.getResultSet();while (rs.next() rows.add(buildOneRow(rs);return rows;5. 关于SQLSERVER2005分页方案的选择1) 2005分页方案可以采用存储过程，和2000的方案兼容。2) 200