java - 插入到具有自增主键的表中

Question

我正在创建一个表，如下所示:

@Override
public void onCreate(SQLiteDatabase db) {
    String sql =
            "CREATE TABLE IF NOT EXISTS users (" +
                    "_id INTEGER PRIMARY KEY, " +
                    "name TEXT NOT NULL, " +
                    "password TEXT NOT NULL);";
    db.execSQL(sql);

    sql = "INSERT INTO users VALUES ('testuser', 'textpassword')";
    db.execSQL(sql);
}

但是当我尝试插入用户时，出现以下异常:

android.database.sqlite.SQLiteException: table users has 3 columns but 2 values were supplied (code 1): , while compiling: INSERT INTO users VALUES ('testuser', 'textpassword')

因为 _id 是主键，为什么它期望它？我也试过 AUTOINCREMENT 但它不起作用。

Answer 1

试试这个

 @Override
public void onCreate(SQLiteDatabase db) {
String sql =
        "CREATE TABLE IF NOT EXISTS users (" +
                "_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, " +
                "name TEXT NOT NULL, " +
                "password TEXT NOT NULL);";
db.execSQL(sql);

sql = "INSERT INTO users(name, password) VALUES ('testuser', 'textpassword')";
db.execSQL(sql);
}

AUTOINCREMENT NOT NULL is missing in your insert query which will increase the value of _id field automatically.