给你一个稍微复杂一点的查询，我设计的
看上图我把第一列标签后面的控件命名有规律，比如计划工厂后面文本框是"计划工厂t"，Exapt命名为"计划工厂c"，后面还隐藏一个listbox，命名为"计划工厂l"。
计划工厂 这个名称本身就是我要查询的表里面包含的字段。
利用这种界面，我要完成一些复杂点的查询：点文本框里的小图标按钮，d出工具，可以输入多条件，条件可以成立为模糊条件（用代替不认识部分），也可以成立为否决条件。
选中Exapt全部否定所成立条件；点击执行按钮，有条件的成立条件，无条件的不成立。
所以这种东西贯穿软件我就不能每个都去做，就只能写一个类文件：
public class conditionset{
public void load_condit(Panel p)
{
foreach (Control ctl in pControls)
{
if (ctl is SkinTextBox)
{
SkinTextBox sktxt = (SkinTextBox)pControls[ctlName];
ListBox list = (ListBox)pControls[sktxtNameSubstring(0, sktxtNameLength - 1) + "l"];
sktxtIconClick += (Object sen, EventArgs ed) =>
{
ctlcondition toolform = new ctlcondition();
if (listItemsCount > 0)
{
sktxtText = "┅";
sktxtReadOnly = true;
}
foreach (var sm in listItems)
{
toolformdvRowsAdd(smToString());
}
toolformShow();
toolformcleari += (Object send, EventArgs er) =>
{
sktxtText = "";
sktxtReadOnly = false;
};
toolformsubm += (Object send, EventArgs er) =>
{
listItemsClear();
foreach (DataGridViewRow dvr in toolformdvRows)
{
if (ConvertToString(dvrCells[0]Value) != "")
{
listItemsAdd(ConvertToString(dvrCells[0]Value));
}
}
sktxtText = "┅";
sktxtReadOnly = true;
};
};
}
}
}
public string condit(Panel p)
{
string master_condition = "";
foreach (Control ctl in pControls)
{
//遍历panel查找条件
#region
string condition = "";
if (ctl is SkinTextBox)
{
//文本框条件组合
#region
SkinTextBox sktxt = (SkinTextBox)pControls[ctlName];
string ziduan_name = sktxtNameSubstring(0, sktxtNameLength - 1);
SkinCheckBox skck = (SkinCheckBox)pControls[ctlNameSubstring(0, ctlNameLength - 1) + "c"];
ListBox list = (ListBox)pControls[ctlNameSubstring(0, ctlNameLength - 1) + "l"];
if (sktxtText != "")
{
if (sktxtText == "┅")
{
string blur_str = "", blur = "";
foreach (var itm in listItems)
{
if (itmToString()Contains(""))
{
if (skckChecked == true)
{
blur += " and " + ziduan_name + " not like '" + itmToString()Replace("", "%") + "'";
}
else
{
blur += " or " + ziduan_name + " like '" + itmToString()Replace("", "%") + "'";
}
}
else
{
blur_str += "'" + ConvertToString(itm) + "',";
}
}
string blur_sql = (blur == "") "" : blurSubstring(4, blurLength - 4)Trim();
string in_condition = "", like_condition = "";
if (skckChecked == true)
{
in_condition = ziduan_name + " not in ";
like_condition = " and ";
}
else
{
in_condition = ziduan_name + " in ";
like_condition = " or ";
}
string contains_sql = (blur_str == "") "" : in_condition + "(" + blur_strSubstring(0, blur_strLength - 1) + ")";
condition = contains_sql + blur_sql;
if (blur_sql != "" && contains_sql != "")
{
condition = contains_sql + like_condition + blur_sql;
}
else
{
condition = contains_sql + blur_sql;
}
}
else
{
if (!sktxtTextContains(""))
{
if (skckChecked == true)
{
condition = ziduan_name + "<>'" + sktxtText + "'";
}
else
{
condition = ziduan_name + "='" + sktxtText + "'";
}
}
else
{
if (skckChecked == true)
{
condition = ziduan_name + " not like '" + sktxtTextReplace("", "%") + "'";
}
else
{
condition = ziduan_name + " like '" + sktxtTextReplace("", "%") + "'";
}
}
}
}
#endregion
}
if (ctl is SkinDateTimePicker)
{
//日期条件组合
#region
if (ctlNameSubstring(ctlNameLength - 1, 1) != "t")
{
SkinDateTimePicker skdate_sta = (SkinDateTimePicker)pControls[ctlName];
SkinDateTimePicker skdate_end = (SkinDateTimePicker)pControls[ctlName + "t"];
if (skdate_statext != "")
{
if (skdate_endtext == "")
{
condition = skdate_staName + "='" + skdate_statext + "'";
}
else
{
condition = skdate_staName + ">='" + skdate_statext + "' and " + skdate_staName + "<='" + skdate_endtext + "'";
}
}
}
#endregion
}
master_condition += (condition == "") "" : "(" + condition + ") and ";
#endregion //遍历panel查找条件
}
string condition_sql = (master_condition == "") "" : master_conditionSubstring(0, master_conditionLength - 5);
return condition_sql;
}
}
工具用一个窗体代替：
public partial class condition : Form{
public condition()
{
InitializeComponent();
}
public event EventHandler subm;
public event EventHandler cleari;
private void submit_Click(object sender, EventArgs e)
{
subm(sender, e);
thisDispose();
}
private void clearit_Click(object sender, EventArgs e)
{
thisDispose();
dvRowsClear();
cleari(sender, e);
}
}
当我们执行多条件的时候就等于拼接条件
使用SQL进行数据查询时,如果查询结果中包含了许多重复的行,可以使用( )去掉结果中的重复行。
ADISTINCT
BDISTINCTROW
CDIFFERENT
DDIFFERENTROW
没什么好办法，只能定义一个临时变量来衔接各个字段,然后判断各个控件是否为空来执行。具体如下：
var tempstr : string ;
begin
tempstr := 'select from table_name where 1=1 ';
with qry1 do
begin
Close ;
SQLClear ;
SQLAdd(tempstr) ;
if edt1Text<>'' then
begin
SQLAdd(' and where column_name like '+ QuotedStr(edt1Text)) ;
end;
(其他判断语句)
Open ;
end;
end;
最好能描述清楚错误的提示内容，这样才能判断问题所在，有时出错可能是其他方面引起的！
试试这条SQL语句：
Dim SqlStr As String
'如果 IN_Date 的字段为 Date 类型
SqlStr = "select from [tb_IN] " _
& "where IN_Date between cast('" & DTPicker1Value & "' as DateTime) And cast('" & DTPicker2Value & "' as DateTime) " _
& "and 供应商 like '%" & Text1Text & "%' "
Adodc1RecordSource = SqlStr
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