Question

我试图在插入期间从c＃.net页面增加MS Access表中的整数。

尝试以下操作时出现语法错误。还不确定我是否应该使用ExecuteNonQuery()？

OleDbCommand cmd = new OleDbCommand("INSERT INTO tblTarget(target,ref) VALUES(@target,(SELECT MAX(ref)+1 FROM tblTarget)", conn);

cmd.Parameters.AddWithValue("@target", TextTitle.Text);
conn.Open();
cmd.ExecuteNonQuery();
conn.Close();

Answer 1

tblTarget之后你错过了一个括号：

OleDbCommand cmd = 
    new OleDbCommand("INSERT INTO tblTarget(target,ref) VALUES(@target,(SELECT MAX(ref)+1 FROM tblTarget))", conn);

以下是对您的代码的一点评论，请尝试使用using模式：

using(var conn = new Connection())
{
    conn.Open();
    string sql = "INSERT INTO tblTarget(target,ref) VALUES(@target,(SELECT MAX(ref)+1 FROM tblTarget))";
    OleDbCommand cmd = new OleDbCommand(sql, conn);

    cmd.Parameters.AddWithValue("@target", TextTitle.Text);

    cmd.ExecuteNonQuery();
}

Answer 2

你错过了一个括号，试试：

INSERT INTO tblTarget(target,ref) VALUES(@target,(SELECT MAX(ref)+1 FROM tblTarget))

但我认为你会遇到其他问题，你需要更接近这个：

INSERT INTO tblTarget ( target, ref )
SELECT @target AS Targ, First((SELECT MAX(ref)+1 FROM tblTarget)) AS MaxRef
FROM tblTarget
GROUP BY @target;

Answer 3

实现目标的正确方法是

string sql = "INSERT INTO tblTarget (target,ref) " + 
             "SELECT ?, MAX(ref)+1 FROM tblTarget";
OleDbCommand cmd = new OleDbCommand(sql, conn);
cmd.Parameters.AddWithValue("@target", TextTitle.Text);
cmd.ExecuteNonQuery();

Answer 4

我不会通过sql或代码进行增量，我们可以使用AutoNumber数据类型来自动增加访问中的值。

string sql = "INSERT INTO tblTarget(target) VALUES(@target)";
using(var conn = new Connection())
using(OleDbCommand cmd = new OleDbCommand(sql, conn))
{
    conn.Open();
    cmd.Parameters.AddWithValue("@target", TextTitle.Text);
    cmd.ExecuteNonQuery();
}

在插入期间增加int

4 个答案: