我在表单上有一个文本框、组合框、按钮和 DataGridView,用于从 MSSQL View (vCustomer) 搜索和返回客户信息。它工作得很好,但我知道我的代码可以更有效率。组合框中的四个项目代表要搜索的列。
是否有一种简单的方法可以将以下内容转换为动态 LINQ to SQL?我是 C# 的新手。我查看了其他一些帖子,但似乎无法正常工作。
public partial class MainForm : Form
{
public MainForm()
{
InitializeComponent();
}
private void MainForm_Load(object sender, EventArgs e)
{
// columns to filter for
string[] list = new string[4];
list[0] = "Name";
list[1] = "CustomerAccountNo";
list[2] = "Telephone";
list[3] = "Postal";
// bind to combobox
cboColumn.DataSource = list;
cboColumn.SelectedIndex = 0;
}
private void btnSearch_Click(object sender, EventArgs e)
{
try
{
Cursor.Current = Cursors.WaitCursor;
CustomerSearchDataContext db = new CustomerSearchDataContext();
IEnumerable<vCustomer> customerQuery = null;
switch (cboColumn.SelectedIndex)
{
case 0:
customerQuery = from c in db.vCustomers
where c.Name.Contains(txtSearch.Text)
orderby c.CustomerAccountNo descending
select c;
break;
case 1:
customerQuery = from c in db.vCustomers
where c.Name.Contains(txtSearch.Text)
orderby c.CustomerAccountNo descending
select c;
break;
case 2:
customerQuery = from c in db.vCustomers
where c.Telephone.Contains(txtSearch.Text)
orderby c.CustomerAccountNo descending
select c;
break;
case 3:
customerQuery = from c in db.vCustomers
where c.Postal.Contains(txtSearch.Text)
orderby c.CustomerAccountNo descending
select c;
break;
}
customerBindingSource.DataSource = customerQuery;
dataGridView1.DataSource = customerBindingSource;
dataGridView1.Columns["CustomerId"].Visible = false;
}
catch (System.Data.SqlClient.SqlException ex)
{
MessageBox.Show("An Error Occured - " + ex.Message,"Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
Cursor.Current = Cursors.Default;
}
}
}
最佳答案
使用[System.Linq.Dynamic][1]
。
从方法中获取条件并在单个查询中使用它。
switch (choice)
{
case case1:
condition = string.Format("{0}.Contains({1})", "Column", "Value"
break;
关于c# - 使用 ComboBox 和 Column.Contains 的动态 Linq To Sql,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/1045146/