make a function to find maxid for any table

Question

1.00/5 (1 vote)

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hi I would like something like this:

C#

public int FindMaxId(string TableName)
     {
       int i =0;
        if ('db.'+TableName+'.ToList().Count() > 0' )
           i = db. TableName.Max(d => d.id);
        return i ;
     }

i know it's wrong .i wanna pass the name of table , and it returns max id. for any table.

Posted 30-Aug-13 19:15pm

Member 8454063

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Bernhard Hiller 2-Sep-13 2:32am

Such a function has a bad smell: what do you need it for? Do you want to create the "next insert id" yourself?

Member 8454063 2-Sep-13 8:01am

yes .your guess is true. i'm coding entity framwork

Bernhard Hiller 2-Sep-13 8:16am

Do not do that! That's a job for the database engine. Only there can concurrency (two users inserting at the same time) be handled correctly. With SQL Server or MS Access, use the Identity or AutoIncrement specifiers for the corresponding column, with Oracle ... bad luck, you'll need a sequence and a trigger.

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Priyanka Bhagwat · Answer 1 · 2013-09-01T18:55:00

Hi...
this code may help you

C#

Public GetMaxid()
{
 con.Open();
            OleDbCommand cmd1 = new OleDbCommand("Select Max(ProductGroupCode) as maxid from ProductGroup_master", con);

            OleDbDataReader oledbrd1 = cmd1.ExecuteReader();

            oledbrd1.Read();
            if (Convert.IsDBNull(oledbrd1["maxid"]))//check if db is NULL 
            {
                strid1 = 1;
                txt_pgrpcode.Text = "1";
            }
            else
            {
                strid1 = Convert.ToInt32(oledbrd1["maxid"]) + 1;
                txt_pgrpcode.Text = strid1.ToString();
            }
            oledbrd1.Close();
}

Hpaay Coding :) :)