我有一个SQL Server查询;当我在SQL Server中运行它时,它返回预期的结果,当我从C#代码调用相同的查询来填充数据集时,没有结果。问题是什么?我的SQL查询如下,以及在SQL Server中运行时的结果
SELECT
t0.brandID, t0.brandName, t0.cdt, t0.udt, t0.brandstatus,
t0.AddedBy ,
(SELECT
AVG(CAST(brandID AS bigint)) FROM brands) AS brandID_AVERAGE
FROM
brands t0
WHERE
t0.cdt >= '2013-11-15 00:00:00'
AND t0.cdt <='2013-11-15 23:59:59'
GROUP BY
t0.brandID, t0.brandName, t0.cdt, t0.udt, t0.brandstatus, t0.AddedBy
以及在SQL Server中运行时上述查询的结果是:
brandID brandName cdt udt brandstatus AddedBy brandID_AVERAGE
10 khasim 2013-11-15 19:14:18.123 2013-11-15 19:14:18.123 1 1 52778
11 khasim 2013-11-15 19:14:18.123 2013-11-15 19:14:18.123 1 1 52778
12 khasim 2013-11-15 19:14:18.123 2013-11-15 19:14:18.123 1 1 52778
13 khasim 2013-11-15 19:14:18.123 2013-11-15 19:14:18.123 1 1 52778
14 khasim 2013-11-15 19:14:18.123 2013-11-15 19:14:18.123 1 1 52778
15 khasim 2013-11-15 19:14:18.123 2013-11-15 19:14:18.123 1 1 52778
16 khasim 2013-11-15 19:14:18.123 2013-11-15 19:14:18.123 1 1 52778
但是当我使用command.Parameters.AddWithValue
从C#调用相同的东西时,我的数据集始终为null。
我的c#代码是
private void button1_Click(object sender, EventArgs e)
{
checkedListBox1.Items.Clear();
Cursor.Current = Cursors.WaitCursor;
string QueryB=@"SELECT t0.brandID, t0.brandName, t0.cdt, t0.udt,
t0.brandstatus, t0.AddedBy,
( SELECT AVG( CAST (brandID AS bigint)) FROM brands )
AS brandID_AVERAGE FROM brands t0
WHERE t0.cdt >= @VALUE1 and t0.cdt <=@VALUE2
group by t0.brandID,t0.brandName,t0.cdt,t0.udt,
t0.brandstatus,t0.AddedBy";
if (textBox1.Text != string.Empty && textBox2.Text != string.Empty)
{
if (checkBox1.Checked == false)
{
try
{
if (QueryB != string.Empty)
{
using (SqlConnection con = new SqlConnection(Properties.Settings.Default.connectionString))
{
con.Open();
SqlCommand cmd = new SqlCommand(QueryB, con);
if (checkBox6.Checked)
{
var sample1 = DateTime.ParseExact(textBox1.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture).ToString("yyyy-MM-dd") + " " + dateTimePicker2.Value.ToString("HH:mm:ss tt");
var sample2 = DateTime.ParseExact(textBox2.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture).ToString("yyyy-MM-dd") + " " + dateTimePicker1.Value.ToString("HH:mm:ss tt");
cmd.Parameters.AddWithValue("@Value1", sample1.ToString());
cmd.Parameters.AddWithValue("@Value2", sample2.ToString());
}
else
{
if (label2.Text.Contains("datetime"))
{
cmd.Parameters.AddWithValue("@Value1", DateTime.ParseExact(textBox1.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture).ToString("MM-dd-yyyy") + " " + "00:00:00.000");
cmd.Parameters.AddWithValue("@Value2", DateTime.ParseExact(textBox2.Text, "dd/MM/yyyy", CultureInfo.InvariantCulture).ToString("MM-dd-yyyy") + " " + "23:59:59.999");
}
else
{
cmd.Parameters.AddWithValue("@Value1", textBox1.Text);
cmd.Parameters.AddWithValue("@Value2", textBox2.Text);
}
}
DataSet ds = new DataSet();
SqlDataAdapter da = new SqlDataAdapter(cmd);
cmd.ExecuteNonQuery();
da.Fill(ds);
con.Close();
dataGridView1.DataSource = ds.Tables[0];
mysource = ds.Tables[0];
dataGridView1.BindingContext = new BindingContext();
foreach (DataGridViewColumn col in dataGridView1.Columns)
{
checkedListBox1.Items.Add(col.HeaderText.ToString());
}
答案 0 :(得分:2)
我不确定你的查询,但你的代码中有一个非常可能的罪魁祸首,它是AddWithValue调用和datetime参数。
您的代码会转换字符串中的datetime值并将其传递给AddWithValue。使用您的区域设置规则进行此转换 AddWithValue不知道底层数据表列是DateTime的事实,因此创建了String类型的参数。此时,参数将传递给需要将字符串值重新转换回DateTime的数据库引擎。使用为您的数据库建立的规则进行此转换,并且可能是值导致查询失败的原因。
只需使用Add方法指定确切的数据类型,并让数据库引擎从参数中正确提取值
cmd.Parameters.Add("@Value1", SqlDbType.DateTime).Value = sample1.Date; //2013/11/15 00:00:00
cmd.Parameters.Add("@Value2", SqlDbType.DateTime).Value = sample2.AddSeconds(86339); // 2013/11/15 23:59:59
答案 1 :(得分:0)
我认为你需要更换 cmd.ExecuteNonQuery(); 同 cmd.ExecuteReader()
虽然我无法测试