[英]How to get data from SQL database to store in combo box - C#
How can i get the value of company_name from Comp table and store it on a comboBox? 如何从Comp表中获取company_name的值并将其存储在comboBox上?
here is my initial code on getting the values from Database and store it on a combobox: 这是我从数据库获取值并将其存储在组合框中的初始代码:
string Sql = "select company_name from JO.dbo.Comp";
SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = new SqlCommand(Sql, conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
comboBox1.Items.Add(ds.Tables[0].Rows[i][0].ToString());
it point out to da.fill(ds)
and says "Could not locate entry in sysdatabases for database 'select company_name from JO'
. No entry found with that name. Make sure that the name is entered correctly." 它指出
da.fill(ds)
并说"Could not locate entry in sysdatabases for database 'select company_name from JO'
条目。找不到该名称的条目。请确保该名称输入正确。”
hope for your reply thanks! 希望您的答复谢谢!
Use datareader it is much simpler \\ 使用datareader要简单得多
string Sql = "select company_name from JO.dbo.Comp";
SqlConnection conn = new SqlConnection(connString);
conn.Open();
SqlCommand cmd = new SqlCommand(Sql, conn);
SqlDataReader DR = cmd.ExecuteReader();
while (DR.Read())
{
combobox1.Items.Add(DR[0]);
}
If you set up your connection string to be something of this sort: 如果将连接字符串设置为以下类型:
string SqlConnectionString = "Data Source=[SERVER];Initial Catalog=[DATABASE];"
Then using that set up, you can set your string 'Sql' as: 然后使用该设置,可以将字符串“ Sql”设置为:
string Sql = "select company_name from dbo.Comp";
This could be a possible set up you could use to read out the values. 这可能是您可以用来读取值的设置。
using (SqlConnection saConn = new SqlConnection(this.ConnectionString))
{
saConn.Open();
string query = "select DBName from dbo.Company";
SqlCommand cmd = new SqlCommand(query, saConn);
using (SqlDataReader saReader = cmd.ExecuteReader())
{
while (saReader.Read())
{
string name = saReader.GetString(0);
combobox1.Add(name);
}
}
saConn.Close();
}
I would like to introduce you a very simple way to SQL data into a combobox as: 我想向您介绍一种将SQL数据导入组合框的非常简单的方法,如下所示:
{
SqlConnection con =new SqlConnection("Data Source=Server_Name;Initial Catalog=Database_Name;integrated security=true");
SqlCommand cmd;
SqlDataReader dr;
private void CashMemoForm_Load(object sender, EventArgs e)
{
con.Open();
cmd = new SqlCommand("Select Column_Name From Table_Name", con);
dr = cmd.ExecuteReader();
while (dr.Read())
{
comboBox1.Items.Add(dr[0]).ToString();
}
}
}
您是否尝试过使用Entity Framework进行数据库访问和dto创建?
Change your line to cmd.CommandType = CommandType.Text;
将行更改为
cmd.CommandType = CommandType.Text;
instead of cmd.CommandType = CommandType.StoredProcedure;
而不是
cmd.CommandType = CommandType.StoredProcedure;
Try this 尝试这个
string Sql = "select Company_ID,company_name from JO.dbo.Comp";
SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = new SqlCommand(Sql, conn);
cmd.CommandType = CommandType.Text;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
comboBox1.DataSource = ds.Tables[0];
comboBox1.DataTextField = "company_name";
comboBox1.DataValueField = "Company_ID";
comboBox1.DataBind();
comboBox1.Items.Insert(0, new ListItem("--Select--", "0"));
}
There is no use of for loop. 没有使用for循环。 you just need to check that whether the dataset contains rows or not.
您只需要检查数据集是否包含行。
string Sql = "select Company_ID,company_name from JO.dbo.Comp";
SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = new SqlCommand(Sql, conn);
cmd.CommandType = CommandType.Text;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
if (ds.Tables[0].Rows.Count > 0)
{
comboBox1.DataSource = ds.Tables[0];
comboBox1.DataTextField = "company_name";
comboBox1.DataValueField = "Company_ID";
comboBox1.DataBind();
comboBox1.Items.Insert(0, new ListItem("Select", "0"));
}
string Sql = "select company_name from JO.dbo.Comp";
SqlConnection conn = new SqlConnection(connString);
SqlCommand cmd = new SqlCommand(Sql, conn);
cmd.CommandType = CommandType.StoredProcedure;
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
comboBox1.Items.Add(ds.Tables[0].Rows[i][0].ToString());
public System.Data.DataTable EmployeeViewAll()
{
DataTable dtbl = new DataTable();
try
{
// Here it shuld be your database Connection String
string connectionString = "Server = .; database = HKS; Integrated Security = true";
using (SqlConnection sqlCon = new System.Data.SqlClient.SqlConnection(connectionString))
{
SqlDataAdapter SqlDa = new SqlDataAdapter("employeeViewAll", sqlCon);
SqlDa.SelectCommand.CommandType = CommandType.StoredProcedure;
SqlDa.Fill(dtbl);
}
return dtbl;
}
catch (Exception)
{
throw;
}
}
public void ComboFill()
{
DataTable dt = new DataTable();
eSP SP = new eSP();
d = SP.EmployeeViewAll();
comboBox1.DataSource = dt;
comboBox1.DisplayMember = "department";
comboBox1.ValueMember = "empName";
}
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