Regarding insert max id in to databse

Question

Dear all,
In my project i used like this for inserting data,
step 1 : getting max id from the table
step 2 : using that max id inserting the data
public datacall{
AccessObj accesdataobj = new AccessObj();
public int access(String s,String s2,String s3)
int i=0;
try
// insert data in first table....
long loginid = accesdataobj.fmaxId("select max(userloginid) from login_tb");
String s31 = "insert into login_tb values(" loginid "," + s1 + ",'"+s2+"','" + s2 + "',null)
i =accesdataobj.insertUpdateDeleteRecord(s31);
//insert data in second table
long userlogid = accesdataobj.fmaxId("select max(userlogid) from userlog_tb");
String s31 = "insert into userlog_tb values(" +userlogid + "," + loginid+ ",'"+s2+"','" + s2 + "',null)
i =accesdataobj.insertUpdateDeleteRecord(s31);
}catch(Exception e){}
return i;
AccessObj.class
public long fmaxId(String s)
throws SQLException
long l = 0L;
Object obj = null;
try
createNewConnection();
stmt = super.cnewcon.createStatement();
ResultSet resultset = stmt.executeQuery(s);
if(resultset.next())
l = resultset.getLong(1);
l++;
catch(Exception exception)
System.out.println("SQL Exception ::" + exception.getMessage());
finally
try
closeConnection()
catch(Exception _ex) { }
return l;
public int insertUpdateDeleteRecord(String s)
throws SQLException
int i = 0;
try
createNewConnection();
stmt = super.cnewcon.createStatement();
i = stmt.executeUpdate(s);
catch(SQLException sqlexception)
System.out.println("Insert Update =" + sqlexception.getMessage());
finally
try
closeConnection();
catch(Exception _ex) { }
return i;
My question is ,
1. My idea for inserting data is correct?.
2. same time two users are inserting data in same time, that time i getting Primary key conflict error is coming in second table.
I need help in this.. inserting primary key, is there any procedure is there.

Answer 1

r035198x wrote:
Better make your database handle the primary keys incrementing than trying to do it in Java code.
Check the manual for your database to see what options are available to enable primary key auto incrementing.++