如何注释Android房间实体内部​​的默认值? [英] How to annotate a default value inside a android room entity?

问题描述

在查看 Room甚至提供默认值的注释吗?

Does Room even provide an annotation for default values?

我当前的解决方案是手动创建相应的表格...

My current solution would be to manually create the corresponding Table ...

CREATE TABLE MyTable (
  ...
  MyDefaultValuedCol  TEXT DEFAULT 'Default Value',
  MyDefaultFlagCol    INT  DEFAULT 1
)

...并将房间"放在顶部.

... and put Room on top.

@Entity(tableName = "MyTable")
class MyClass {
    ...

    public String MyDefaultValuedCol;

    public boolean MyDefaultFlagCol;

}

推荐答案

随着房间持久性2.2.0的发布，在@ColumnInfo批注中添加了一个新属性，可用于指定列的默认值.参见文档.

With the release of room persistence 2.2.0, there's a new property added to @ColumnInfo annotation which can be used to specify the default value of a column. See documentation.

@Entity(tableName = "users")
data class User(
    @PrimaryKey val id: Long,
    @ColumnInfo(name = "user_name", defaultValue = "temp") val name: String
    @ColumnInfo(name = "last_modified", defaultValue = "CURRENT_TIMESTAMP" ) val lastModified: String
)

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