具有默认值的 ORMLite 列

Question

我有一个用默认值定义的非空列：

@DatabaseField(dataType = DataType.TIME_STAMP, columnDefinition = "DATETIME DEFAULT CURRENT_TIMESTAMP NOT NULL") private Date createdDate;

尝试保存未设置 createdDate 字段的行时，出现以下错误：

[SQLITE_CONSTRAINT_NOTNULL] A NOT NULL constraint failed (NOT NULL constraint failed:

ORMLite 可能试图明确地将 NULL 值插入该字段。将 persisted = false 添加到注释中可以避免这种情况，但随后不会在 table 创建时创建该列。

有没有办法在创建列的同时告诉 ORMLite 在 INSERT 时忽略该列？

Answer 1

Is there a way to create the column, but to also tell ORMLite to ignore that column on INSERT?

您缺少的是 readOnly = true setting for @DatabaseField。引用 javadocs:

Set this to be true (default false) if this field is a read-only field. This field will be returned by queries however it will be ignored during insert/create statements. [ just added: ] This can be used to represent create or modification dates with the values being generated by the database.

我只是使用了以下字段定义（至少有 H2）并且工作正常：

@DatabaseField(columnDefinition = "DATETIME DEFAULT CURRENT_TIMESTAMP NOT NULL",
    readOnly = true, canBeNull = false)
private Date createdDate;

您不需要指定 dataType，如果您这样做，我认为您的字段应该是 Timestamp 类型。顺便说一句，我刚刚更正的在线文档中缺少此功能。

具有默认值的 ORMLite 列

ORMLite column with default

null

ormlite

sql-insert