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' 

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

Code#region Code 
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;
}
#endregion