控件代码及测试例子：http://files.cnblogs.com/wuhuacong/CommonSearch.rar
使用场景: 在列表页面中,一般有好几个条件, 用户进行查询时候,需要根据这几个条件进行过滤查询.但在组装这些过滤条件的时候，代码比较烦琐臃肿，本组件代码为解决该问题而设计。
使用目的: 1.减少对参数非空的条件判断 2. 可以构造出参数化的DbCommand对象,简化操作. 3.适当修改后可以用于其他数据访问的参数化参数生成.4.构造Sql语句或者参数化条件更加易读
1. 生成SQL条件语句
如有几个字段，需要根据不同的字段进行过滤，想生成的SQL语句如下：
Where (1=1) AND AA2 Like '%AA2Value%' AND AA6 >= 'Value6' AND AA7 <= 'value7' AND AA3 = 'Value3' AND AA4 < 'Value4' AND AA5 > 'Value5' AND AA <> '1'
那么代码如下：
SearchCondition search = new SearchCondition(); search.AddCondition("AA", 1, SqlOperator.NotEqual) .AddCondition("AA2", "AA2Value", SqlOperator.Like) .AddCondition("AA3", "Value3", SqlOperator.Equal) .AddCondition("AA4", "Value4", SqlOperator.LessThan) .AddCondition("AA5", "Value5", SqlOperator.MoreThan) .AddCondition("AA6", "Value6", SqlOperator.MoreThanOrEqual) .AddCondition("AA7", "value7", SqlOperator.LessThanOrEqual); string conditionSql = search.BuildConditionSql();
2. 生成基于Enterprise Library的DbCommand对象
Database db = DatabaseFactory.CreateDatabase(); SearchCondition search = new SearchCondition(); search.AddCondition("Name", "测试" , SqlOperator.Like) .AddCondition("ID", 1, SqlOperator.MoreThanOrEqual); DbCommand dbComand = search.BuildDbCommand(db, "select Comments from Test", " Order by Name"); using (IDataReader dr = db.ExecuteReader(dbComand)) { while (dr.Read()) { this.txtSql.Text += "\r\n" + dr["Comments"].ToString(); } }
下面是该控件的类对象图解
下面我们比较一下使用该控件和不使用在列表查询页面中的代码，可以看出使用了控件后的代码大大较少了，并且可读性也增强了
1. 使用该控件, 列表查询页面中的代码
private string GetCondition() { SearchCondition search = new SearchCondition(); search.AddCondition("GroupID", this.ddlUserGroup.SelectedValue, SqlOperator.Equal, true)//班组ID .AddCondition("DealGroupName", this.ddlDealGroup.SelectedValue, SqlOperator.Equal, true)/*消缺单位*/ .AddCondition("VisioStationID", this.ddlStation.SelectedValue, SqlOperator.Like, true)//变电站 .AddCondition("VisioImageID", this.ddlLine.SelectedValue, SqlOperator.Like, true)/*馈线*/ .AddCondition("BugNo", this.txtBugNo.Text.Trim(), SqlOperator.Like, true)/*编号*/ .AddCondition("Finder", this.ddlFindUser.SelectedValue, SqlOperator.Like, true)/*发现人*/ .AddCondition("CheckUser", this.ddlCheckUser.SelectedValue, SqlOperator.Like, true)//验收人 .AddCondition("DeviceBug.BugType", this.ddlBugType.SelectedValue, SqlOperator.Equal, true)//缺陷类别 .AddCondition("CurrentState", this.ddlCurrentState.SelectedValue, SqlOperator.Equal, true)//处理状态 .AddCondition("FindDate", this.txtFindBeginDate.Text.Trim(), SqlOperator.MoreThanOrEqual, true)//发现日期 .AddCondition("FindDate", this.txtFindEndDate.Text.Trim(), SqlOperator.LessThanOrEqual, true)//发现日期 .AddCondition("EndDate", this.txtEndBeginDate.Text.Trim(), SqlOperator.MoreThanOrEqual, true)//消缺日期 .AddCondition("EndDate", this.txtEndEndDate.Text.Trim(), SqlOperator.LessThanOrEqual, true);//消缺日期 return search.BuildConditionSql(); }
2. 普通做法，不使用控件，列表查询页面中的代码
private string GetCondition() { string condition = ""; if ( this.ddlUserGroup.SelectedValue != "0") { condition += string.Format( " GroupID = {0}" , this.ddlUserGroup.SelectedValue.ToString() ); } //消缺单位 if ( this.ddlDealGroup.SelectedValue != "0") { if (condition == "") { condition += string.Format( " DealGroupName = '{0}'" , this.ddlDealGroup.SelectedItem.Text ); } else { condition += string.Format( " And DealGroupName = '{0}'" , this.ddlDealGroup.SelectedItem.Text ); } } if (this.txtStation.Text.Trim() != "") { if (condition == "") { condition += string.Format(" Station like '%{0}%'",this.txtStation.Text.Trim() ); } else { condition += string.Format(" And Station like '%{0}%' ",this.txtStation.Text.Trim() ); } } if (this.txtLineName.Text.Trim() != "") { if (condition == "") { condition += string.Format(" LineName like '%{0}%'",this.txtLineName.Text.Trim() ); } else { condition += string.Format(" And LineName like '%{0}%' ",this.txtLineName.Text.Trim() ); } } //编号 if (this.txtBugNo.Text.Trim() != "") { if (condition == "") { condition += string.Format("BugNo like '%{0}%'",this.txtBugNo.Text.Trim() ); } else { condition += string.Format(" And BugNo like '%{0}%'",this.txtBugNo.Text.Trim() ); } } //发现人 if ( ddlFindUser.SelectedIndex >= 1 ) { if (condition == "") { condition += string.Format("Finder like '%{0}%'",ddlFindUser.SelectedValue ); } else { condition += string.Format(" And Finder like '%{0}%'",ddlFindUser.SelectedValue ); } } //验收人 if ( this.ddlCheckUser.SelectedIndex >= 1 ) { if (condition == "") { condition += string.Format("CheckUser like '%{0}%'",this.ddlCheckUser.SelectedValue ); } else { condition += string.Format(" And CheckUser like '%{0}%'",this.ddlCheckUser.SelectedValue ); } } //缺陷类别 if (this.ddlBugType.SelectedValue.Trim() != "#") { if (condition == "") { condition += string.Format("DeviceBug.BugType={0}",this.ddlBugType.SelectedValue.Trim() ); } else { condition += string.Format(" And DeviceBug.BugType={0}",this.ddlBugType.SelectedValue.Trim() ); } } //处理状态 if (this.ddlCurrentState.SelectedValue.Trim() != "#") { if (condition == "") { condition += string.Format("CurrentState='{0}'",this.ddlCurrentState.SelectedValue.Trim() ); } else { condition += string.Format(" And CurrentState='{0}'",this.ddlCurrentState.SelectedValue.Trim() ); } } //发现日期 if (this.txtFindBeginDate.Text.Trim() != "") { if (condition == "") { condition += string.Format("FindDate>='{0}'",this.txtFindBeginDate.Text.Trim() ); } else { condition += string.Format(" And FindDate>='{0}'",this.txtFindBeginDate.Text.Trim() ); } } if (this.txtFindEndDate.Text.Trim() != "") { if (condition == "") { condition += string.Format("FindDate<='{0}'",this.txtFindEndDate.Text.Trim() ); } else { condition += string.Format(" And FindDate<='{0}'",this.txtFindEndDate.Text.Trim() ); } } //消缺日期 if (this.txtEndBeginDate.Text.Trim() != "") { if (condition == "") { condition += string.Format("EndDate>='{0}'",this.txtEndBeginDate.Text.Trim() ); } else { condition += string.Format(" And EndDate>='{0}'",this.txtEndBeginDate.Text.Trim() ); } } if (this.txtEndEndDate.Text.Trim() != "") { if (condition == "") { condition += string.Format("EndDate<='{0}'",this.txtEndEndDate.Text.Trim() ); } else { condition += string.Format(" And EndDate<='{0}'",this.txtEndEndDate.Text.Trim() ); } } return condition; }
本文转自博客园伍华聪的博客，原文链接：列表查询组件代码, 简化拼接条件SQL语句的麻烦，如需转载请自行联系原博主。