用WHERE子句更新JOIN另一个表

Question

我有下表：

习惯

ID INT PRIMARY KEY

NUMBER INT FOREIGN KEY

DATE DATE

DONE BOOL

---

HABIT_DESCRIPTION

NUMBER INT PRIMARY KEY

NAME VARCHAR

DESCRIPTION VARCHAR

我要对HABIT中特定行进行更新，其中HABIT_DESCRIPTION的名称为

我尝试过：

ContentValues cv = new ContentValues();
    cv.put(HABIT_COL_DONE, true);
    String whereclause = HABIT_DESCRIPTION_NAME+ "='water'";
    return db.update("HABIT",cv,whereclause,null);

Answer 1

由于 SQLite 不支持UPDATE语句中的联接，因此可以使用EXISTS：

String whereclause = 
    "EXISTS (SELECT 1 FROM HABIT_DESCRIPTION WHERE NUMBER = HABIT.NUMBER AND DESCRIPTION = ?)";
String param = "water";
return db.update("HABIT", cv, whereclause, new String[] {param});