删除超过x天的android SQLite行
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deleting android SQLite rows older than x days
提问by George D
I want to delete all rows in table MYTABLE which are older than x days. Column SAVE_DATE Long is the time when the row was inserted in table.
我想删除表 MYTABLE 中所有早于 x 天的行。列 SAVE_DATE Long 是该行插入表中的时间。
I tried this but apparently it deletes all my rows:
我试过这个，但显然它删除了我所有的行：
long daysInMiliSec = new Date().getTime() - X
* (24L * 60L * 60L * 1000L);
return db.delete(MYTABLE , SAVE_DATE
" <= ?", new String[] { "" + daysInMiliSec }
What is wrong?
怎么了？
回答by Yaqub Ahmad
Below query will delete data older than 2 days:
以下查询将删除超过 2 天的数据：
String sql = "DELETE FROM myTable WHERE Save_Date <= date('now','-2 day')";
db.execSQL(sql);
回答by user136036
Since it's the first hit on google some more explanation for beginners:
You do not need the time/date functions from the main program you use to access the sqlite DB but use the sqlite date functions directly.
由于它是 google 上的第一次命中，因此对初学者有更多解释：
您不需要用于访问 sqlite 数据库的主程序中的时间/日期函数，而是直接使用 sqlite 日期函数。
You create the table with the row entry for the age with for example:
您可以使用年龄的行条目创建表，例如：
CREATE TABLE IF NOT EXISTS test (id INTEGER PRIMARY KEY, text TEXT, age INTEGER)
You write to it with
你写信给它
INSERT INTO test (text, age) VALUES ("bla", datetime('now'))
Here I used 'datetime' because this also will let you later search for hours/minutes/seconds. If you don't need that 'date('now')' is enough.
在这里我使用了“日期时间”，因为这也可以让您稍后搜索小时/分钟/秒。如果您不需要 'date('now')' 就足够了。
Here is an explanation for the date function: https://www.sqlite.org/lang_datefunc.html
这里是日期函数的解释：https: //www.sqlite.org/lang_datefunc.html
To select everything older than for example 5 minutes:
要选择早于 5 分钟的所有内容：
SELECT * FROM test WHERE age <= datetime('now', '-5 minutes')
You can see more of those possibilities on the website above under the paragraph 'Modifiers'.
您可以在上面网站的“修饰符”段落下看到更多这些可能性。
回答by Brian Feldman
Delete data older than 2 days when the timestamp or date field is stored in milliseconds or an epoch integer.
当时间戳或日期字段以毫秒或纪元整数存储时，删除超过 2 天的数据。
DELETE FROM update_log WHERE timestamp <= strftime('%s', datetime('now', '-2 day'));
回答by Simon
With the latest version of ORMLite for SQLite Android: http://ormlite.com/sqlite_java_android_orm.shtml, you may achieve this by using the following code:
使用适用于 SQLite Android 的最新版 ORMLite：http://ormlite.com/sqlite_java_android_orm.shtml ，您可以使用以下代码实现此目的：
String sql = "DELETE FROM graph WHERE time <= 1522405117";
dbHelper.getWritableDatabase().execSQL(sql);
