Question

我想从sqlite中删除一行但是我的senario是当我第一次输入文本字段时它应该插入到表中，当我再次输入具有相同值的文本字段时，它不应该作为第二行输入，它应该删除第一个条目并获得更新，表ID应该只保留为1。

我不知道怎么做，请在我第一次做数据库时建议我。

感谢。

创建表：

            "CREATE TABLE secure" + DatabaseContract.RetailDatabaseEntry.TABLE_NAME_SETTINGS + " (" +
                    DatabaseContract.RetailDatabaseEntry.COLUMN_ID_SETTINGS+ " INTEGER PRIMARY KEY AUTOINCREMENT," +
                    DatabaseContract.RetailDatabaseEntry.COLUMN_FIRSTNAME + " TEXT UNIQUE ON CONFLICT REPLACE,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_LASTNAME +" TEXT,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_PHONENUMBER +" TEXT,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_EMAILADDRESS +" TEXT,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_ADDRESSLINE1 +" TEXT,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_ADDRESSLINE2 +" TEXT,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_LOCALITY +" TEXT,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_CITY +" TEXT,"+
                    DatabaseContract.RetailDatabaseEntry.COLUMN_PINCODE +" TEXT" + 
                    ")";

Answer 1

您需要将UNIQUE约束添加到您希望不希望具有重复值的表的列中。如下所示

COLUMN_NAME+ " TEXT UNIQUE, "

Answer 2

它没有你想象的那么强硬。在创建数据库时，请将值设为uniique：

db.execSQL("CREATE TABLE secure (" +
            "_id INTEGER PRIMARY KEY AUTOINCREMENT," +
            "name TEXT UNIQUE ON CONFLICT REPLACE," +
            "value TEXT" +
            ");");

当您尝试在上表中反复插入相同的“名称”时，sqlite将自动为您插入和替换。因此没有重复的值。

如何删除sqlite中的匹配条目

2 个答案: