[英]Reading columns using WHERE clause on MS Access passing combobox textvalue
I am working on a windows application written in C# and using MS Access 2003 as my database. 我正在使用C#编写的Windows应用程序上工作,并使用MS Access 2003作为数据库。 I am facing strange problem, when I write the query
我写查询时遇到奇怪的问题
SELECT * FROM mytable WHERE columnname='"+combobox.text+"'
and execute using oledbadapter, the dataset visualizer doesn't recognise the where
clause and returns empty table. 并使用oledbadapter执行,数据集可视化器将无法识别
where
子句并返回空表。 Whereas 鉴于
SELECT * FROM mytable WHERE columnname='"+integervalue+"
will return the filtered column. 将返回过滤的列。
Here is my code snippet: 这是我的代码段:
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;
}
output: returns empty table when I pass the text value in the where-clause. 输出:当我在where子句中传递文本值时,返回空表。
I have resolved this issue. 我已经解决了这个问题。 it was the case of empty spaces in my access 2003 table columns.
这是我的Access 2003表列中有空白的情况。 so used a trim() to clear the spaces while selecting the columns in where clause.
因此在选择where子句中的列时使用了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;
}
Sometimes silly mistakes makes u crave like anything :-) 有时候愚蠢的错误会让你渴望任何东西:-)
:-) :-)
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