代码渲染样式测试

@Override  
public  String getPrimaryKey(String tableName,  JdbcTemplate  template)  
{  
String sqlQuery =  "SELECT CONSTRAINT_NAME FROM user_constraints WHERE TABLE_NAME = ? AND constraint_type = 'P'"; 
 List<String> res =  template.queryForList(sqlQuery,  String.class, tableName); 
 if  (res.size()  ==  0) 
 {  return  null;  } 
 return res.get(0);  
}