Question

我在c＃中创建了一个表单，我需要自动生成ID，当用户点击清除数据按钮时，该ID已自动显示。而且ID的格式应该是LEL5-序列号（序列号总是在增加的情况下，如1,2,3，..）

Ex：我的第一张iD是LEL5-1，

我的第二个记录是LEL5-2

请帮忙。谢谢。

static int EJDS_id = 1;
 string code;

private void button1_Click_1(object sender, EventArgs e)
    {

        EJDS_id = EJDS_id + 1;
        txtjobno.Text = "LEL5-" + EJDS_id.ToString();

    }

Answer 1

string test = "LEL5-1";
int xxxx = Convert.ToInt32(test.Substring(5));
xxxx++;
string result = string.Format("LEL5-{0}", xxxx);

Answer 2

创建一个名为SERIAL_NUMBERS的表：

create table SERIAL_NUMBERS(
    ID INT NOT NULL PRIMARY KEY,
    LASTNUMBER INT NOT NULL);

然后插入一个字符串以存储最后一个值：

insert into SERIAL_NUMBERS(ID, LASTNUMBER) values (1, 0);

然后在后面的代码中添加以下命名空间：

using System.Data;
using System.Data.OleDb;
using System.Web.Configuration;

然后在你的代码背后：

protected void button1_Click_1(object sender, EventArgs e) {
    UpdateLastNumber();
    txtjobno.Text = "LEL5-" + GetLastNumber().ToString();
}

protected int GetLastNumber(){
    int last = 0;
    OleDbConnection con = new OleDbConnection(WebConfigurationManager.ConnectionStrings["YourConnectionStringnameFromWebConfigFile"].ConnectionString);
    OleDbCommand cmd = new OleDbCommand("select lastnumber from serial_numbers where id = 1", con); // I added the condition just to be sure that only one value will be queried
    con.Open();
    last = Convert.ToInt32(cmd.ExecuteScalar().ToString());
    con.Close();
    return last;
}

protected void UpdateLastNumber(){
    OleDbConnection con = new OleDbConnection(WebConfigurationManager.ConnectionStrings["YourConnectionStringnameFromWebConfigFile"].ConnectionString);
    OleDbCommand cmd = new OleDbCommand("update serial_numbers set lastnumber = lastnumber + 1 where id = 1", con); // I added the condition just to be sure that only one value will be queried
    con.Open();
    cmd.ExecuteNonQuery();
    con.Close();
}

用户单击Clear_data按钮时在文本框中添加自动生成ID的代码

2 个答案: