Set ASP.Net GridView CheckBox Checked on Page Load based on database record using C# and VB.Net

i have this gridview, i want their checkbox checked if their posi no is in the database on page load from the table cylinder

i have three(3) cylinders available with posino on issuesheet N'['A101','A102','A103']

On page load i want the available cylinders whose posino appears on the issue sheet to be checked (check box)

My code

CREATE TABLE [dbo].[issuesheet](
	[id] [int] IDENTITY(1,1) NOT NULL,
	[pid] [int] NULL,
	[machine] [nvarchar](255) NULL,
	[orderquantity] [float] NULL,
	[workdocket] [nvarchar](50) NULL,
	[cylinders] [nvarchar](255) NULL,
	
	[comment] [nvarchar](255) NULL,
	[solvents] [nvarchar](255) NULL
) ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[issuesheet] ON 
GO
INSERT [dbo].[issuesheet] ([id], [pid], [machine], [orderquantity], [workdocket], [cylinders]) VALUES (1, 206, N'Griller', 67543, N'DCK001', N'['A101','A102','A103'])
GO
SET IDENTITY_INSERT [dbo].[issuesheet] OFF
GO
ALTER TABLE [dbo].[issuesheet] ADD  DEFAULT ('[]') FOR [cylinders]
GO
/////////////////////////////////////////////////////////////////////
Cylinder Table

CREATE TABLE [dbo].[cylinder](
	[id] [int] NULL,
	[posino] [nvarchar](50) NULL,
	[pid] [nvarchar](50) NULL,
	[diameter] [nvarchar](50) NULL
) ON [PRIMARY]
GO
INSERT [dbo].[cylinder] ([id], [posino], [pid], [diameter]) VALUES (1, N'A101', N'206', N'25mm')
GO
INSERT [dbo].[cylinder] ([id], [posino], [pid], [diameter]) VALUES (2, N'A102', N'206', N'24mm')
GO
INSERT [dbo].[cylinder] ([id], [posino], [pid], [diameter]) VALUES (3, N'A103', N'206', N'26mm')
GO
INSERT [dbo].[cylinder] ([id], [posino], [pid], [diameter]) VALUES (4, N'A104', N'206', N'27mm')

public partial class gridcontinue : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            BindUserDetails1();
        }
    }

    protected void BindUserDetails1()
    {
        string constr1 = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con1 = new SqlConnection(constr1))
        {
            using (SqlDataAdapter sda1 = new SqlDataAdapter(" SELECT  * from cylinde ", con1))
            {

                // Response.Write(sda1);
                using (DataTable dt1 = new DataTable())
                {
                    sda1.Fill(dt1);
                    avDetails.DataSource = dt1;
                    avDetails.DataSource = dt1;
                    avDetails.DataBind();
                }
            }
        }

        //Required for jQuery DataTables to work.
        if (avDetails.Rows.Count > 0)
        {
            avDetails.UseAccessibleHeader = true;
            avDetails.HeaderRow.TableSection = TableRowSection.TableHeader;
        }
    }

    protected void OnChckedChanged(object sender, EventArgs e)
    {
        CheckBox chk = (CheckBox)sender;
        GridViewRow row = (GridViewRow)chk.NamingContainer;

        string number = row.Cells[1].Text;
        string pid ="206";

        string constring = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constring))
        {
            string acceptedCylinder = GetAcceptedCylinder(pid);
            if (chk.Checked)
            {
                if (acceptedCylinder == "[]")
                {
                    using (SqlCommand cmd = new SqlCommand("UPDATE issuesheet SET cylinders = @cylinders where pid='206'", con))
                    {
                        cmd.Parameters.AddWithValue("@cylinders", "['" + number.Trim() + "']");
                        con.Open();
                        cmd.ExecuteNonQuery();
                        con.Close();
                    }
                    ClientScript.RegisterStartupScript(this.GetType(), "Popup", "ShowPopup('Record Inserted successfully.');", true);
                }
                else
                {
                    List<string> cylinderNo = acceptedCylinder.Replace("[", "").Replace("]", "").Replace("'", "").Split(',').ToList();
                    cylinderNo.Add(number);
                    using (SqlCommand cmd = new SqlCommand("UPDATE issuesheet SET cylinders = @cylinders where pid='206'", con))
                    {
                        cmd.Parameters.AddWithValue("@cylinders", "['" + string.Join("','", cylinderNo.Distinct()) + "']");
                        con.Open();
                        cmd.ExecuteNonQuery();
                        con.Close();
                    }
                    ClientScript.RegisterStartupScript(this.GetType(), "Popup", "ShowPopup('Record Updated Successfully.');", true);
                }
            }
            else
            {
                if (!string.IsNullOrEmpty(acceptedCylinder))
                {
                    List<string> cylinderNo = acceptedCylinder.Replace("[", "").Replace("]", "").Replace("'", "").Split(',').ToList();
                    cylinderNo.Remove(number);
                    using (SqlCommand cmd = new SqlCommand("UPDATE issuesheet SET cylinders = @cylinders where pid='206' ", con))
                    {
                        cmd.Parameters.AddWithValue("@cylinders", cylinderNo.Distinct().Count() > 0 ? "['" + string.Join("','", cylinderNo.Distinct()) + "']" : "[]");
                        con.Open();
                        cmd.ExecuteNonQuery();
                        con.Close();
                    }
                    ClientScript.RegisterStartupScript(this.GetType(), "Popup", "ShowPopup('Record Deleted Successfully.');", true);
                }
            }
        }
    }

    private string GetAcceptedCylinder(string pid)
    {
        string acceptCylinder = "";
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        using (SqlConnection con = new SqlConnection(constr))
        {
            using (SqlCommand cmd = new SqlCommand())
            {
                cmd.CommandText = "SELECT cylinders FROM issuesheet WHERE pid=@pid ";
                cmd.Connection = con;
                cmd.Parameters.AddWithValue("@pid", 206);
                con.Open();
                acceptCylinder = Convert.ToString(cmd.ExecuteScalar());
                con.Close();
            }
        }
        return acceptCylinder;
    }   
}