C# winforms ms-access-2003 oledbdataadapter

在 MS Access 上使用 WHERE 子句传递组合框文本值来读取列

发布于 2024-11-17 01:30:16 字数 786 浏览 5 评论 0原文

我正在开发一个用 C# 编写的 Windows 应用程序，并使用 MS Access 2003 作为我的数据库。我面临奇怪的问题，当我编写查询

SELECT * FROM mytable WHERE columnname='"+combobox.text+"'

并使用 oledbadapter 执行时，数据集可视化工具无法识别 where 子句并返回空表。而

SELECT * FROM mytable WHERE columnname='"+integervalue+"

将返回过滤后的列。

这是我的代码片段：

private void viewinfo_Click(object sender, EventArgs e){
    dataGridView1.Visible = true;
    OleDbCommand cmd;
    string schoolname = cmbschoolname.Text;
    OleDbDataAdapter da = new OleDbDataAdapter("select  * from tblmedic where medicalschool ='"+combobox.text+"'", conn);
    DataTable dt = new DataTable();
    da.Fill(dt);
    dataGridView1.DataSource = dt;
}

输出：当我在 where 子句中传递文本值时，返回空表。

原文

I am working on a windows application written in C# and using MS Access 2003 as my database. I am facing strange problem, when I write the query

SELECT * FROM mytable WHERE columnname='"+combobox.text+"'

and execute using oledbadapter, the dataset visualizer doesn't recognise the where clause and returns empty table. Whereas

SELECT * FROM mytable WHERE columnname='"+integervalue+"

will return the filtered column.

Here is my code snippet:

private void viewinfo_Click(object sender, EventArgs e){
    dataGridView1.Visible = true;
    OleDbCommand cmd;
    string schoolname = cmbschoolname.Text;
    OleDbDataAdapter da = new OleDbDataAdapter("select  * from tblmedic where medicalschool ='"+combobox.text+"'", conn);
    DataTable dt = new DataTable();
    da.Fill(dt);
    dataGridView1.DataSource = dt;
}

output: returns empty table when I pass the text value in the where-clause.

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冷情 2024-11-24 01:30:16

我已经解决了这个问题。这是我的 access 2003 表列中有空格的情况。因此，在选择where子句中的列时，使用trim()来清除空格。

private void viewinfo_Click(object sender, EventArgs e){
    dataGridView1.Visible = true;
    OleDbCommand cmd;
    string schoolname = cmbschoolname.Text;
    OleDbDataAdapter da = new OleDbDataAdapter("select  * from tblmedic where medicalschool ='"+combobox.text.ToString().Trim()+"'", conn);
    DataTable dt = new DataTable();
    da.Fill(dt);
    dataGridView1.DataSource = dt;
}

有时愚蠢的错误会让你渴望任何东西:-)

:-)

I have resolved this issue. it was the case of empty spaces in my access 2003 table columns. so used a trim() to clear the spaces while selecting the columns in where clause.

private void viewinfo_Click(object sender, EventArgs e){
    dataGridView1.Visible = true;
    OleDbCommand cmd;
    string schoolname = cmbschoolname.Text;
    OleDbDataAdapter da = new OleDbDataAdapter("select  * from tblmedic where medicalschool ='"+combobox.text.ToString().Trim()+"'", conn);
    DataTable dt = new DataTable();
    da.Fill(dt);
    dataGridView1.DataSource = dt;
}

Sometimes silly mistakes makes u crave like anything :-)

:-)

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