删除查询不起作用 SQL c#

Question

我一直在尝试从 table 中删除行，但我编写的代码不起作用，我不确定是 SQL 语法还是代码本身，visual studio 没有抛出任何错误，它只是毫无问题地启动程序，在我单击删除按钮后，程序冻结，我什至无法关闭它。如果我在执行此操作后检查数据库，它保持不变。

另外，如果我解释得不是很好，我很抱歉，英语不是我的母语，所以对我来说有点难，提前谢谢你。

      private void button1_Click(object sender, EventArgs e)
    {
        MessageBox.Show("DOING STUFF");
        bool check = true;
        do
        {
            string connectionString = @"Data Source=.\wintouch;Initial Catalog=bbl;User ID=sa;Password=Pa$$w0rd";
            string queryString = string.Empty;
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                queryString = "DELETE FROM wgcdoccab WHERE serie ='1' tipodoc ='FSS' AND and contribuinte ='999999990' and  datadoc = CONVERT(varchar(10),(dateadd(dd, -2, getdate())),120) ";                    
                SqlCommand command = new SqlCommand(queryString, connection);
                //command.Connection.Open();
                command.ExecuteNonQuery();

            }
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                queryString = "SELECT * FROM wgcdoccab WHERE serie ='1' tipodoc ='FSS' AND and contribuinte ='999999990' and  datadoc = CONVERT(varchar(10),(dateadd(dd, -2, getdate())),120) ";

                using (SqlCommand command = new SqlCommand(queryString, connection))
                using (SqlDataReader reader = command.ExecuteReader())
                {
                    if (reader.HasRows)
                    {
                        check = true;
                    }
                    else
                    {
                        check = false;
                        MessageBox.Show("STILL DOING STUFF");
                    }
                    command.Connection.Close();
                }
            }
        }
        while (check);

Answer 1

DELETE 和 SELECT 的内联查询都不正确。更正后的查询将如下所示。

删除查询

DELETE FROM wgcdoccab WHERE serie ='1' AND tipodoc ='FSS' AND contribuinte ='999999990' 
 and  datadoc = CONVERT(varchar(10),(dateadd(dd, -2, getdate())),120)

Select查询

SELECT * FROM wgcdoccab WHERE serie ='1' AND tipodoc ='FSS' AND    contribuinte ='999999990' 
and  datadoc = CONVERT(varchar(10),(dateadd(dd, -2, getdate())),120)

Answer 2

我不确定你怎么想 SQL 命令是如何工作的，但它们肯定不是异步的，所以你既不需要循环也不需要第二个 using 块来检查行是否你刚刚删除的还在。删除过程只有在所有行都被删除后才会结束。

另外，您发布的代码不可能是真实的代码，因为您的 WHERE 子句中的语法无效，您应该得到一个 SQL 异常。

因此您的代码可以缩短为以下内容（也修复了 WHERE 子句）：

private void button1_Click(object sender, EventArgs e)
{
    MessageBox.Show("DOING STUFF");

        string connectionString = @"Data Source=.\wintouch;Initial Catalog=bbl;User ID=sa;Password=Pa$$w0rd";
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            connection.Open();

            string queryString = "DELETE FROM wgcdoccab WHERE serie ='1' tipodoc ='FSS' AND and contribuinte ='999999990' and  datadoc = CONVERT(varchar(10),(dateadd(dd, -2, getdate())),120) ";                    
            SqlCommand command = new SqlCommand(queryString, connection);
            command.ExecuteNonQuery();
        }
}

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