1.根據條件,檢查有無記錄。
有,則刪除
無,則新增。
2.刪除的風險在於刪除了其它字段的信息。所於有必要在刪除前,先讀取出來其它字段的信息。再把新信息同記錄一同寫入。
這種方式也是更新數據的一種方式。
{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"typ
{"type":"doc","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockq
{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":2},"content":[{"type":"text","text":"一、導讀"}]},{
{"type":"doc","content":[{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null