Problème avec AUTO_INCREMENT ou primary key ?

CREATE table HOMOLOGIE(UG Varchar(20), GID Varchar(20), IDoligo Varchar(20), score Float(4,1), percent Float(5,2), length Int(8), nbmeralign Int(3), primary key(IDoligo,UG));

else { 
	String []tab = new String[10];
	pstmt = connexion.prepareStatement
	("SELECT COUNT(*) Number FROM HOMOLOGIE");
	ResultSet rs = pstmt.executeQuery();
	rs.next(); int idunik = rs.getInt("Number")+1; 
		// je m'en servait pour mettre un identifiant ... mais plus m1tenant !
	do {	
		tab = Line.split("\t");
		// tab contient :
	// 0 ~ oligo / 1 ~ genbank / 2 ~ GI / 3 ~ UG / 4 ~ length / 5 ~ score / 6 ~ percent / 7 ~ align
					
try { 
		float floatscore = Float.parseFloat(tab[5]);
		float floatpercent = Float.parseFloat(tab[6]);
		int intalign = Integer.parseInt(tab[7]);
			if (intalign == 70){ 
				if (floatpercent >= 100.0){
					if (floatscore >= 130.0){
						if (tab[3].equals("null") == false){
				test = true; System.out.println(floatscore+" "+floatpercent+" "+intalign);
									}
								}
							}
						}
					}
catch (Exception exp){  }
					
	if(test == true) {
						
		pstmt = connexion.prepareStatement
("INSERT INTO HOMOLOGIE (UG,GID,IDoligo,score,percent,length,nbmeralign) VALUES (?,?,?,?,?,?,?)");
		if(tab[3].equals("null")) pstmt.setNull(1, java.sql.Types.NULL);
		else pstmt.setString(2, tab[3]);
		if(tab[0].equals("null")) pstmt.setNull(1, java.sql.Types.NULL);
		else pstmt.setString(3, tab[2]);
		if(tab[2].equals("null")) pstmt.setNull(1, java.sql.Types.NULL);
		else pstmt.setString(4, tab[0]);
		if(tab[5].equals("null")) pstmt.setNull(1, java.sql.Types.NULL);
		else pstmt.setFloat(5, Float.parseFloat(tab[5]));
		if(tab[6].equals("null")) pstmt.setNull(1, java.sql.Types.NULL);
		else pstmt.setFloat(6, Float.parseFloat(tab[6]));
		if(tab[4].equals("null")) pstmt.setNull(1, java.sql.Types.NULL);
		else pstmt.setInt(7, Integer.parseInt(tab[4]));
		if(tab[7].equals("null")) pstmt.setNull(1, java.sql.Types.NULL);
		else pstmt.setInt(8, Integer.parseInt(tab[7]));
		rows = pstmt.executeUpdate();
						
	pstmt = connexion.prepareStatement("INSERT INTO GENE (GI,GenBank) VALUES(?,?)");
		f(!tab[2].equals("null")) pstmt.setString(1, tab[2]);
		if(!tab[1].equals("null")) pstmt.setString(2, tab[1]);
		rows = pstmt.executeUpdate();
						
			}
				test=false;
	} while ((Line = buffR.readLine()) != null);

Configuration: PC: ACER
OS: Windows Vista / Linux Mandriva
Software : Eclipse, Photoshop