插入异常-查了一个通宵的低级错误

String sql = "insert into finance(f_name) values(?)";
conn = JDBCUtil.getConnection();//连接数据库
int count = 0;
try {
psmt = conn.prepareStatement(sql);
smt.setString(1, "xxoo");
count = psmt.executeUpdate(sql);
//count = psmt.executeUpdate();