如何从文本框中获取值到sql查询？ [英] How do I get a value from a textbox into a sql query?

问题描述

嗨。



我对SQL语句有疑问。

我有MonthCalendar我选择日期。然后日期显示在一个文本框中。

在表单上我也有一个datagridview。



我尝试了很多不同的转换器。

 DateTime condition = Convert.ToDateTime（textBox1.Text）; 
 sda =  new  SqlDataAdapter（  SELECT * FROM tbl_Tidrapport WHERE Datum LIKE + condition +  ，cn）; 
 dt =  new  DataTable（）; 
 sda.Fill（dt）; 
 dataGridView1.DataSource = dt; 

总是收到错误。



请帮忙...... 。

如何在SQL查询中获取日期？

解决方案

LIKE不起作用，它适用于字符串：和机会它是不匹配的，因为Datum值与微秒不完全匹配 - 这是等式检查所期望的。

所以试试这个：

< pre lang =c＃> DateTime condition = Convert.ToDateTime（textBox1.Text）.Date;
sda = new SqlDataAdapter（ SELECT * FROM tbl_Tidrapport WHERE CONVERT（date，Datum）= @DT，cn）;
sda.SelectCommand.Properties.AddWithValue（ @ DT，condition）;
dt = new DataTable（）;
sda.Fill（dt）;
dataGridView1.DataSource = dt;

首先 - 不要直接插入查询。而是使用SqlParameters。这有助于避免SQL注入危险。



您的查询有第二个问题：条件将用作字段名称，因为它在查询中没有单引号。参数也可以处理。



试试这个：

 DateTime condition = Convert.ToDateTime（textBox1 。文本）; 
 dt =  new  DataTable（）; 
 使用（SqlCommand cmd = cn.CreateCommand（））
 {
 cmd.CommandText =   SELECT * FROM tbl_Tidrapport WHERE Datum LIKE @condition; 
 cmd.CommandType = CommandType.Text; 
 cmd.Parameters.Add（ new  SqlParameter（  @condition，SqlDbType.DateTime）{Value = condition}）; 
 使用（SqlDataAdapter sda =  new  SqlDataAdapter（cmd））
 {
 cn.Open（）; 
 sda.Fill（dt）; 
 cn.Close（）; 
} 
} 
 

另外，使用赞 使用日期类型并没有任何意义。我不知道你想用它做什么，但我把它留在我的解决方案中。



如果你想要喜欢问题的帮助那么让我们我在评论中知道



祝你好运：）

语法错误搜索

请参阅此 SQL Like查询 [ ^ ]



do类似这样的事情

  string  condition =  ; 
  var  sda =  new  SqlDataAdapter（  SELECT * FROM tbl_Tidrapport WHERE Datum LIKE'％ + condition +  ％'，cn）; 

注意：注意 SQL注入 [ ^ ]

SQL注入攻击 [ ^ ]

Hi.

I have a question about SQL statement.
I have a MonthCalendar where I select a date. The date then shows up in a textbox.
On the form I also have a datagridview.

I have tried alot of diffrent converters.

DateTime condition = Convert.ToDateTime(textBox1.Text);
            sda = new SqlDataAdapter("SELECT * FROM tbl_Tidrapport WHERE Datum LIKE "+ condition +"", cn);
            dt = new DataTable();
            sda.Fill(dt);
            dataGridView1.DataSource = dt;

Always get error.

Please help....
How can I get the date in the SQL query?

解决方案

LIKE won't work, it's for strings: and the chances are that it doesn't match because the Datum value doesn't exactly match to the microsecond - which is what an equality check will expect.
So try this:

DateTime condition = Convert.ToDateTime(textBox1.Text).Date;
sda = new SqlDataAdapter("SELECT * FROM tbl_Tidrapport WHERE CONVERT(date, Datum) = @DT", cn);
sda.SelectCommand.Properties.AddWithValue("@DT", condition);
dt = new DataTable();
sda.Fill(dt);
dataGridView1.DataSource = dt;

First of all - Do not insert into your query directly. Instead use SqlParameters. This helps avoid SQL Injection dangers.

Your query has a second issue: the "condition" would be used as a field name as it has no single quotes within the query. Parameters take care of that too.

Try this:

DateTime condition = Convert.ToDateTime(textBox1.Text);
dt = new DataTable();
using (SqlCommand cmd = cn.CreateCommand())
{
    cmd.CommandText = "SELECT * FROM tbl_Tidrapport WHERE Datum LIKE @condition";
    cmd.CommandType = CommandType.Text;
    cmd.Parameters.Add(new SqlParameter("@condition", SqlDbType.DateTime) {Value = condition});
    using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
    {
        cn.Open();
        sda.Fill(dt);
        cn.Close();
    }
}

Also, using "Like" with a date type doesn't really make any sense. I have no idea what you are trying to achieve with that, but I have left it in my solution.

If you want help with the "Like" issue then let me know in a comment

Good luck :)

Syntax error for Like search
refer this SQL Like query [^]

do something like this

string condition = "";
        var   sda = new SqlDataAdapter("SELECT * FROM tbl_Tidrapport WHERE Datum LIKE '%" + condition + "%'", cn);

Note: Be aware of SQL Injection [^]
SQL Injection Attacks[^]

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