Creating new column breaks sqlite android
In SQLite, you can create a new column in a table using the ALTER TABLE
statement. Here is an example:
ALTER TABLE your_table_name ADD COLUMN new_column_name data_type;
Replace your_table_name
with the name of the table you want to modify, new_column_name
with the name of the new column, and data_type
with the data type of the new column (e.g. INTEGER
, TEXT
, REAL
, etc.).
For example, to add a new column called new_column
with a data type of INTEGER
to a table called my_table
, you would use the following statement:
ALTER TABLE my_table ADD COLUMN new_column INTEGER;
Note that you can only add columns to the end of the table, so if you want to add a column in a specific position, you will need to use a more complex statement that involves creating a temporary table and then renaming it to replace the original table.
In Android, you can use the SQLiteDatabase
class to execute the ALTER TABLE
statement. Here is an example:
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("ALTER TABLE my_table ADD COLUMN new_column INTEGER");
Make sure to replace this
with the context of your Android app, and my_table
with the name of the table you want to modify.
Also, you can use execSQL
method to execute the SQL query, but make sure to use the correct syntax and replace the placeholders with the actual values.
You can also use rawQuery
method to execute the SQL query, it will return a Cursor
object that you can use to retrieve the results.
Cursor cursor = db.rawQuery("ALTER TABLE my_table ADD COLUMN new_column INTEGER", null);
Please note that the ALTER TABLE
statement can only be executed on a database that is not currently being used by another process. If you are trying to modify a table that is being used by another process, you will need to use a different approach, such as creating a new table and then copying the data from the old table to the new table.