how to get max id in sql server in C# and put it in label

Question

1.60/5 (2 votes)

See more:

hello

how to get max id in database table and show it in label
i do this code to get the max id +1 in SQL DB
SELECT MAX (patient_id)+1 FROM patient_data
and make this code in C#

C#

SqlConnection cnz = new SqlConnection(ConfigurationManager.ConnectionStrings["lap_appConnectionString"].ConnectionString);
                SqlCommand cmdzs = new SqlCommand("SELECT MAX (patient_id) FROM patient_data ", cnz);
                    cmdzs.CommandType = CommandType.Text;
                    cmdzs.Connection.Open();
                    SqlDataReader dr = cmdzs.ExecuteReader();
                    if (dr.HasRows)
                    {
                        while (dr.Read())
                        {

                            max_id_lbl.Text = dr["MAX (patient_id)"].ToString();
                        
                        }
                    }

but i error here

C#

max_id_lbl.Text = dr["MAX (patient_id)"].ToString();

so what is wrong here
thanks and sorry for bad english

Posted 10-Nov-13 2:41am

Abdullaziz Said

Add a Solution

Comments

CHill60 10-Nov-13 8:45am

Try changing your sql to read MAX (patient_id) as Result and then use max_id_lbl.Text = dr["Result"].ToString();

u mani 25-Jul-14 4:43am

max_id_lbl.Text = dr["MAX (patient_id)"].ToString(); instead of this write like this

max_id_lbl.Text = dr[0].ToString();

2 solutions

Solution 4

try like this it will work

C#

SqlConnection cnz = new SqlConnection(ConfigurationManager.ConnectionStrings["lap_appConnectionString"].ConnectionString);
                SqlCommand cmdzs = new SqlCommand("SELECT MAX (patient_id) FROM patient_data ", cnz);
                    cmdzs.CommandType = CommandType.Text;
                    cmdzs.Connection.Open();
                    SqlDataReader dr = cmdzs.ExecuteReader();
                    if (dr.HasRows)
                    {
                        while (dr.Read())
                        {
 
                            max_id_lbl.Text = dr[0].ToString();
                        
                        }
                    }

Posted 24-Jul-14 22:42pm

u mani

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Mahesh Bailwal · Accepted Answer · 2013-11-10T03:07:00

I suggest you to use ExecuteScalar whenever you want to retrieve single value from database as it perform better than ExecuteReader and also always use using statement with SqlConnection object to make sure it get disposed properly. You can try below code snippet.

string conStr = ConfigurationManager.ConnectionStrings["lap_appConnectionString"].ConnectionString;
          using (SqlConnection cnz = new SqlConnection(conStr))
          {
              SqlCommand cmdzs = new SqlCommand("SELECT MAX (patient_id) as max_patient_id FROM patient_data ", cnz);
              cmdzs.CommandType = CommandType.Text;
              cnz.Open();
              max_id_lbl.Text = cmdzs.ExecuteScalar().ToString();
          }