更新错误使用内部联接 [英] Error wit update use inner join

问题描述

大家好，我有两个查询的问题使用内部联接更新和插入。



我有三个表关系。



我的应用程序是与Access数据库连接的C＃Windows Forms。

Hello guys, I have problem with two querys Update and Insert using Inner Join.

I have three tables relation ship.

My application is C# Windows Forms connected with Access Database.

The follow fields are type Int:

Atados

Reorden

Pc_Atado

Vol


This is my query:

private void btnAct_Click(object sender, EventArgs e)
        {
            String sql = "UPDATE tLEADS INNER JOIN (tBUNDLES INNER JOIN tLOCALES ON tBUNDLES.IdBUNDLES = tLOCALES.IdLOCALES) ON tLEADS.IdLEADS = tBUNDLES.IdBUNDLES SET tLEADS Mnbr='" + txtMaq.Text + "', Rack=" + txtRack.Text + ", Nivel='" + txtNiv.Text + "', Localizacion='" + txtLoc.Text + "', Atados=" + txtAta.Text + ", Reorden=" + txtReor.Text + ", Pcs_Atado=" + txtPcs.Text + ", Vol=" + txtVol.Text + ", WHERE IdLEADS = '" + txtBusLead.Text + "'";
            try
            {
                con.Open();
                adapter = new OleDbDataAdapter(cmd);
                if (MessageBox.Show("Esta seguro que quiere actualizar el registro ??", "ALERTA: Actualizara un registro", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning) == DialogResult.OK)
                {
                    cmd.ExecuteNonQuery();
                    MessageBox.Show("Registro actualizado correctamente...!", "Registro Actualizado", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                }
                con.Close();
                CargaDg();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                con.Close();
            }
        }
    }
Let me know you comments please.

Dan



我的尝试：

Dan

What I have tried:

private void btnAct_Click(object sender, EventArgs e)
        {
            String sql = "UPDATE tLEADS INNER JOIN (tBUNDLES INNER JOIN tLOCALES ON tBUNDLES.IdBUNDLES = tLOCALES.IdLOCALES) ON tLEADS.IdLEADS = tBUNDLES.IdBUNDLES SET tLEADS Mnbr='" + txtMaq.Text + "', Rack=" + txtRack.Text + ", Nivel='" + txtNiv.Text + "', Localizacion='" + txtLoc.Text + "', Atados=" + txtAta.Text + ", Reorden=" + txtReor.Text + ", Pcs_Atado=" + txtPcs.Text + ", Vol=" + txtVol.Text + ", WHERE IdLEADS = '" + txtBusLead.Text + "'";
            try
            {
                con.Open();
                adapter = new OleDbDataAdapter(cmd);
                if (MessageBox.Show("Esta seguro que quiere actualizar el registro ??", "ALERTA: Actualizara un registro", MessageBoxButtons.OKCancel, MessageBoxIcon.Warning) == DialogResult.OK)
                {
                    cmd.ExecuteNonQuery();
                    MessageBox.Show("Registro actualizado correctamente...!", "Registro Actualizado", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                }
                con.Close();
                CargaDg();
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                con.Close();
            }
        }
    }

推荐答案

不要这样做！永远不要连接字符串来构建SQL命令。它让您对意外或故意的SQL注入攻击持开放态度，这可能会破坏您的整个数据库。总是使用参数化查询。



连接字符串时会导致问题，因为SQL会收到如下命令：

Don't do it like that! Never concatenate strings to build a SQL command. It leaves you wide open to accidental or deliberate SQL Injection attack which can destroy your entire database. Always use Parameterized queries instead.

When you concatenate strings, you cause problems because SQL receives commands like:

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

就SQL而言，用户添加的引号会终止字符串，并且您会遇到问题。但情况可能更糟。如果我来并改为输入：x'; DROP TABLE MyTable; - 然后SQL收到一个非常不同的命令：

The quote the user added terminates the string as far as SQL is concerned and you get problems. But it could be worse. If I come along and type this instead: "x';DROP TABLE MyTable;--" Then SQL receives a very different command:

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

哪个SQL看作三个单独的命令：

Which SQL sees as three separate commands:

SELECT * FROM MyTable WHERE StreetAddress = 'x';

完全有效的SELECT

A perfectly valid SELECT

DROP TABLE MyTable;

完全有效的删除表格通讯和

A perfectly valid "delete the table" command

--'

其他一切都是评论。

所以它确实：选择任何匹配的行，从数据库中删除表，并忽略其他任何内容。



所以总是使用参数化查询！或者准备好经常从备份中恢复数据库。你经常定期备份，不是吗？



当你完成整个应用程序的更新时 - 因为如果你只错过一个它就会出现问题 - 你可能会发现你的另一个问题同时发生了。

And everything else is a comment.
So it does: selects any matching rows, deletes the table from the DB, and ignores anything else.

So ALWAYS use parameterized queries! Or be prepared to restore your DB from backup frequently. You do take backups regularly, don't you?

And when you have finished updating your entire app - because if you miss just one it'll be a problem - you may well find your other problem has gone at the same time.

这篇关于更新错误使用内部联接的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！