防SQL注入 生成参数化的通用分页查询语句


            使用这种通用的存储过程进行分页查询，想要防SQL注入，只能对输入的参数进行过滤，例如将一个单引号“'”转换成两个单引号“''”，但这种做法是不安全的，厉害的黑客可以通过编码的方式绕过单引号的过滤，要想有效防SQL注入，只有参数化查询才是最终的解决方案。但问题就出在这种通用分页存储过程是在存储过程内部进行SQL语句拼接，根本无法修改为参数化的查询语句，因此这种通用分页存储过程是不可取的。但是如果不用通用的分页存储过程，则意味着必须为每个具体的分页查询写一个分页存储过程，这会增加不少的工作量。 经过几天的时间考虑之后，想到了一个用代码来生成参数化的通用分页查询语句的解决方案。代码如下： 复制代码 代码如下: public class PagerQuery { private int _pageIndex; private int _pageSize = 20; private string _pk; private string _fromClause; private string _groupClause; private string _selectClause; private string _sortClause; private StringBuilder _whereClause; public DateTime DateFilter = DateTime.MinValue; protected QueryBase() { _whereClause = new StringBuilder(); } /**//// <summary> /// 主键 /// </summary> public string PK { get { return _pk; } set { _pk = value; } } public string SelectClause { get { return _selectClause; } set { _selectClause = value; } } public string FromClause { get { return _fromClause; } set { _fromClause = value; } } public StringBuilder WhereClause { get { return _whereClause; } set { _whereClause = value; } } public string GroupClause { get { return _groupClause; } set { _groupClause = value; } } public string SortClause { get { return _sortClause; } set { _sortClause = value; } } /**//// <summary> /// 当前页数 /// </summary> public int PageIndex { get { return _pageIndex; } set { _pageIndex = value; } } /**//// <summary> /// 分页大小 /// </summary> public int PageSize { get { return _pageSize; } set { _pageSize = value; } } /**//// <summary> /// 生成缓存Key /// </summary> /// <returns></returns> public override string GetCacheKey() { const string keyFormat = "Pager-SC:{0}-FC:{1}-WC:{2}-GC:{3}-SC:{4}"; return string.Format(keyFormat, SelectClause, FromClause, WhereClause, GroupClause, SortClause); } /**//// <summary> /// 生成查询记录总数的SQL语句 /// </summary> /// <returns></returns> public string GenerateCountSql() { StringBuilder sb = new StringBuilder(); sb.AppendFormat(" from {0}", FromClause); if (WhereClause.Length > 0) sb.AppendFormat(" where 1=1 {0}", WhereClause); if (!string.IsNullOrEmpty(GroupClause)) sb.AppendFormat(" group by {0}", GroupClause); return string.Format("Select count(0) {0}", sb); } /**//// <summary> /// 生成分页查询语句，包含记录总数 /// </summary> /// <returns></returns> public string GenerateSqlIncludeTotalRecords() { StringBuilder sb = new StringBuilder(); if (string.IsNullOrEmpty(SelectClause)) SelectClause = "*"; if (string.IsNullOrEmpty(SortClause)) SortClause = PK; int start_row_num = (PageIndex - 1)*PageSize + 1; sb.AppendFormat(" from {0}", FromClause); if (WhereClause.Length > 0) sb.AppendFormat(" where 1=1 {0}", WhereClause); if (!string.IsNullOrEmpty(GroupClause)) sb.AppendFormat(" group by {0}", GroupClause); string countSql = string.Format("Select count(0) {0};", sb); string tempSql = string.Format( "WITH t AS (SELECT ROW_NUMBER() OVER(ORDER BY {0}) as row_number,{1}{2}) Select * from t where row_number BETWEEN {3} and {4};", SortClause, SelectClause, sb, start_row_num, (start_row_num + PageSize - 1)); return tempSql + countSql; } /**//// <summary> /// 生成分页查询语句 /// </summary> /// <returns></returns> public override string GenerateSql() { StringBuilder sb = new StringBuilder(); if (string.IsNullOrEmpty(SelectClause)) SelectClause = "*"; if (string.IsNullOrEmpty(SortClause)) SortClause = PK; int start_row_num = (PageIndex - 1)*PageSize + 1; sb.AppendFormat(" from {0}", FromClause); if (WhereClause.Length > 0) sb.AppendFormat(" where 1=1 {0}", WhereClause); if (!string.IsNullOrEmpty(GroupClause)) sb.AppendFormat(" group by {0}", GroupClause); return string.Format( "WITH t AS (SELECT ROW_NUMBER() OVER(ORDER BY {0}) as row_number,{1}{2}) Select * from t where row_number BETWEEN {3} and {4}", SortClause, SelectClause, sb, start_row_num, (start_row_num + PageSize - 1)); } }  使用方法： 复制代码 代码如下: PagerQuery query = new PagerQuery(); query.PageIndex = 1; query.PageSize = 20; query.PK = "ID"; query.SelectClause = "*"; query.FromClause = "TestTable"; query.SortClause = "ID DESC"; if (!string.IsNullOrEmpty(code)) { query.WhereClause.Append(" and ID= @ID"); }  a) GenerateCountSql ()方法生成的语句为： Select count(0) from TestTable Where 1=1 and ID= @ID b) GenerateSql()方法生成的语句为： WITH t AS (SELECT ROW_NUMBER() OVER(ORDER BY ECID DESC) as row_number, * from TestTable where 1=1 and ID= @ID) Select * from t where row_number BETWEEN 1 and 20 c) GenerateSqlIncludetTotalRecords()方法生成的语句为： WITH t AS (SELECT ROW_NUMBER() OVER(ORDER BY E.ECID DESC) as row_number,* from TestTable where 1=1 and ID= @ID) Select * from t where row_number BETWEEN 1 and 20;Select count(0) from ECBasicInfo where 1=1 and ID= @ID; 注意：以上代码生成的SQL语句是曾对SQL SERVER 2005以上版本的，希望这些代码对大家有用