code: private static String joinWhereAndGetValue(List<Field> fields,
  			String logicOperate, List<Object> values, Object obj) {
  		StringBuilder sb = new StringBuilder();
  		int fieldSize = fields.size();
  		for(int i = 0; i < fieldSize; i++) {
  			Column column = fields.get(i).getAnnotation(Column.class);
  			sb.append(getColumnName(column)).append("=?");
  			if(i < fieldSize - 1) {
  				sb.append(" ").append(logicOperate).append(" ");
  			}
  			Object val = DOInfoReader.getValue(fields.get(i), obj);
  			if(val != null && column.isJSON()) {
  				val = JSON.toJson(val);
  			}
  			values.add(val);
  		}
  		return sb.toString();
  	}
docs: 拼凑where子句，并把需要的参数写入到values中。返回sql【不】包含where关键字
  
  @param fields
  @param logicOperate 操作符，例如AND
  @param values
  @param obj
  @return