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Import table into existing sqlite database android

I am in a situation where the user has a sqlite database that has data that should not be tampered with at all. Essentially I want to import a table from a .csv file or something along those lines into their database without touching any of the data.
I notice that there is no library frmo what I can see that does explicitly this. My knowledge with SQLite isn't as comfortable as I'd like it to be so I'm unsure of where to go here.
Should I just read the file line per line copying the data and then inserting it into the created table? Each table will have 400 records, not too many so I figure it can't be that inefficient. My inexperience is what worries me thinking I will somehow damage the data. Hoping to prevent mistakes and liability here..

Here's one way:
Create a new temporary database table without a primary key (so you can verify it before copying it.)
e.g.
CREATE TABLE salespeopleTMP (
id INTEGER,
first_name TEXT NOT NULL,
last_name TEXT NOT NULL,
commission_rate REAL NOT NULL
);
and there is existing data in the table that looks like this:
sqlite> select * from salespeople;
1|Fred|Flinstone|10.0
2|Barney|Rubble|10.0
If I now have a CSV data file named people.txt that looks like this:
3,John,Doe,5.0
4,Jane,Smith,5.0
Import the CSV data into that temporary SQLite table
You can import the CSV data into my SQLite table with these two commands:
sqlite> .separator ','
sqlite> .import people.txt salespeopleTMP
Use the INSERT INTO command to import the data from your temporary
table into your actual table
insert into salespeople select * from salespeopleTMP
Delete your temporary table salespeopleTMP
based on and bug fixed from https://alvinalexander.com/android/sqlite-csv-import-data-table-primary-key

Delete all record from the data base

I am working on a project on android where thousands of tables exist.Unfortunately I do not have fresh data base so what can I do to delete all record from all tables. i am using sqlite database .If it is possible please tell me.

If you want to remove the entire rows/data from table, then it's better to drop the table and recreate it. This is the usual convention and for this reason SqLiteOpenHelper has onCreate() and onUpgrade() method which creates table or upgrades it, when table is dropped, or database version is changed
For deleting/dropping table, the code fragment is
db.execSQL("DROP TABLE IF EXISTS " + YOUR_TABLE);
Check the first answer for reference What happens if an android app, which creates database, is then uninstalled?

drop or delete a sqlite - table as fast as possible on Android device

I have a table with 1400 rows. Every row has a blob field which holds data between 10kb and 500kb. I need to delete that table. It takes me 3.5 minutes to delete the table and 3 minutes to drop the table. Thats too long for the users.
How can I remove that table as fast as possible ? ( No rollback needed or any security, just remove it. )
I already tried the following.
1. Set pagesize :
sqlitedatabase.setPageSize(8000);
sqlitedatabase.execSQL("DROP TABLE IF EXISTS " + sTableName);
2. deactivate journallog which did not work.
sqlitedatabase.rawQuery("PRAGMA journal_mode=OFF",null);
sqlitedatabase.execSQL("DROP TABLE IF EXISTS " + sTableName);
this doesn't work for me. journal log, which I guess takes a lot of time, is still be written on to the disk.

From the SQLite manual (with emphasis added):
SQLite is slower than the other databases when it comes to dropping tables. This probably is because when SQLite drops a table, it has to go through and erase the records in the database file that deal with that table. MySQL and PostgreSQL, on the other hand, use separate files to represent each table so they can drop a table simply by deleting a file, which is much faster.
You do have the option of creating and storing multiple database files, which you can then manage from a single connection with ATTACH and DETACH queries.
Here's an example I just ran in SQLite3's command-line client:
sqlite> ATTACH 'example.sqlite' AS example;
sqlite> CREATE TABLE example.ex ( a INTEGER );
sqlite> INSERT INTO example.ex VALUES (1),(2),(3);
sqlite> SELECT * FROM example.ex;
1
2
3
sqlite> DETACH example;
sqlite>
Since the ex table is in its own file, example.sqlite, I can simply detach that DB from the connection and delete the entire file, which will be much faster.
Bear in mind that the number of DBs you can attach is fairly low (with default compile options: 7). I've also read that foreign keys aren't supported in this scenario, though that info might be out of date.

I got a solution for me, which speeds up the deletion 6 times.
with
connection_read.enableWriteAheadLogging();
I drop my table in 30 Seconds. Without it it takes the mentoined 3 minutes.
enableWriteAheadLogging is an alternative journal log which is way faster.

Why not just put the drop table code in a separate thread? The user shouldn't have to wait for the app to drop a table.

Android SQLite Database Update

I have a pre-established SQLite Database in my application. It has a table with rows about 20 rows of text. I want to be able to add additional rows to the table without deleting all of the previous information. The only way I have seen which would allow me to do this is to delete all of the previous databases and then recreate it with the new rows. There must be a better way. Thanks for your help!

Are you confusing rows with columns?
If you really do mean rows then as antlersoft points out, using the SQL INSERT INTO statement will simply add a new row to a table without affecting any existing table data. This is one of the most basic and commonly used SQL statements.
If you actually mean you need to add columns then use the SQL ALTER TABLE statement.
See..
SQL INSERT INTO statement
SQL ALTER TABLE statement

The Android framework, as it relates to SQLite (using a SQLiteOpenHelper) provides two distinct methods for handling database lifecycles - onCreate(), used when the database needs to be created from scratch, and onUpgrade(<database>, int oldVersion, int newVersion) for handling updates. You can specify the "new" version number in the constructor for the superclass of your SQLiteOpenHelper, and the framework knows to call onUpgrade() based on this parameter and the internal version # in the actual sqlite database.
So, to modify your database during a version change just override onUpgrade() and run whatever SQLite stuff that you need.

Empty tables size in sqlite db

I am creating a db for my android app which requires different tables for different types of users. Basically, if user type A logs in he will use Table A, user type B logs in he will use Table B and similarly Table C.
Should I go ahead and create 3 tables and use only the table which the user type has logged in? Would this have any significant memory implications (size of the db)? That is, if the table doesn't contain data, would the sqlite db still allocate some space (other than for definitions of the columns).
The other way would be to check the user type and dynamically create the table at runtime once user logs in. I prefer the first method if there isn't much space used.
Any pointers or suggestions would be very useful.

The SQLite DB will occupy some space to store the table structures and the constraints/indexes. Why don't u just create the database tables (w/o any data) using SQLite Browser and check the size of the database file.
Would help you decide.

I think instead of creating all tables at one go use SQL queries to create tables as and when needed. If its not needed anymore you can even drop the table.