我想将0.50添加到整数,只是我很困惑。我不知道该怎么做。有代码;
if (checkBox1.Checked)
{
keko.Open();
double mesai = Convert.ToDouble(textBox4.Text);
mesai = mesai + 0.50;
double maaş = Convert.ToDouble(textBox4.Text);
maaş += 1;
textBox4.Text = mesai.ToString() + maaş.ToString();
MySqlCommand cmd = new MySqlCommand(
"Update calisanlist Set Gun '" + textBox4.Text + "' where (Adı,Soyadı) '" + textBox1.Text + "','"+textBox2.Text+"'",
keko);
cmd.ExecuteNonQuery();
keko.Close();
按钮下方有一个复选框。如果我按下按钮而没有选中框,它会自动添加1好吧这里没问题。但是,当我选中框并按下按钮时,我有一条错误消息。
MySql.Data.MySqlClient.MySqlException
:
'你的SQL语法有错误;查看与MySQL服务器版本对应的手册,以便在''7,58'附近使用正确的语法,其中(Adı,Soyadı)'Egemen','Ören''在第1行。
我不知道如何解决它请帮助我
看来,你可能会遇到问题
textBox4.Text = mesai.ToString() + maaş.ToString();
想象一下,当mesai
是3.5
时,maaş
是4.1
:你将在3.54.1
中有textBox4.Text
,这不是有效的double
值。你可能意味着
double mesai = Convert.ToDouble(textBox4.Text) + 0.5;
//TODO: check isn't it a typo? Both mesai and maaş are from the same textBox4.Text
double maaş = Convert.ToDouble(textBox4.Text) + 1;
textBox4.Text = (mesai + maaş).ToString();
不要硬编码查询,而是对其进行参数化
...
// Keep sql readable
// and parameterized
string sql =
@"update calisanlist
set Gun = @prm_Gun
where Adı = @prm_Adi and
Soyadı = @prm_Soyadı";
// wrap IDisposable into "using"
using (MySqlCommand cmd = new MySqlCommand(sql, keko)) {
// I don't know underlying database types, that's why I've put AddWithValue
//TODO: change syntax to cmd.Parameters.Add(name, datatype).Value = ...
cmd.Parameters.AddWithValue("@prm_Gun", Convert.ToDouble(textBox4.Text));
cmd.Parameters.AddWithValue("@prm_Adi", textBox1.Text);
cmd.Parameters.AddWithValue("@prm_Soyadı", textBox2.Text);
cmd.ExecuteNonQuery();
}
...