Question

我正在使用2017年的微软视觉工作室社区我的数据库来自MS Access（Microsoft.Jet.OLEDB.4.0）
我认为我的查询在chkNum时存在冲突这些是我的样本选择查询，总共4个。

connection.Open();
OleDbCommand command = new OleDbCommand();
command.Connection = connection;

if (frmTopic.chkRndQ == true && frmTopic.chkNum == false)
{
    chkQ = true;
    command.CommandText = @"SELECT TOP " + numR + " QUESTION,C1,C2,C3,C4,ANSWER,CONTENT FROM " + tab + " WHERE CONTENT IN ('" + top + "') ORDER BY RND(-(1000*ID)*Time())";
    remain = frmTopic.randNo;
    num = numR;
}

if (frmTopic.chkRndQ == false && frmTopic.chkNum == false)
{
    chkQ = false;
    command.CommandText = @"SELECT TOP " + numR + " QUESTION,C1,C2,C3,C4,ANSWER,CONTENT FROM " + tab + " WHERE CONTENT IN ('" + top + "')";
    remain = frmTopic.randNo;
    num = numR;
}

if (frmTopic.chkRndQ == true && frmTopic.chkNum == true)
{
    chkQ = true;
    command.CommandText = @"SELECT TOP " + numX + " QUESTION,C1,C2,C3,C4,ANSWER,CONTENT,NUM FROM " + tab + " WHERE CONTENT IN ('" + top + "') AND NUM BETWEEN " + num1 + " AND " + num2 + " ORDER BY RND(-(1000*ID)*Time())";
    remain = frmTopic.no;
    num = numX;
}

if (frmTopic.chkRndQ == false && frmTopic.chkNum == true)
{
    chkQ = false;
    command.CommandText = @"SELECT TOP " + numX + " QUESTION,C1,C2,C3,C4,ANSWER,CONTENT,NUM FROM " + tab + " WHERE CONTENT IN ('" + top + "') AND NUM BETWEEN " + num1 + " AND " + num2 + "";
    remain = frmTopic.no;
    num = numX;
}

OleDbDataAdapter dAdap = new OleDbDataAdapter(command);
dTable = new DataTable();
dAdap.Fill(dTable);
currentRow = 0;
lblNo.Text = currentNo.ToString();
nextRow();
connection.Close();

当我运行程序时，查询应根据条件选择numR或numX数据。

如果我选择检查chkNum，请输入num1和num2。问题是，如果我选择取消选中chkNum，它将只查询先前的numX数据而不是numR数据。但如果我再次检查chkNum并输入num1和num2，或者我只是不选中chkNum，它会正确查询。

与chkNum的不同之处在于它只会从表格中的一个内容中选择指定的n个数据。如果未选中，它将从表格内的多个内容中随机选择指定的n个数据。

与使用C＃表格

0 个答案: