How to create table using sqlite database in android?

问题

public class MyAct extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        SQLiteDatabase db = openOrCreateDatabase("MyDb",MODE_PRIVATE,null);
        db.execSQL("CREATE TABLE IF NOT EXISTS MyTab (Month INT(2),Date INT(2),Year INT(4),Event VARCHAR;");
        db.execSQL("INSERT INTO MyTab VALUES (0,1,2012,'mini_proj');");
        db.close();

    }
}

I have written this small snippet to create a table, but it's not working. What is the problem with this code?

回答1:

In your first query, you are missing a closing brace:

CREATE TABLE IF NOT EXISTS MyTab (
    Month INT(2),
    Date INT(2),
    Year INT(4),
    Event VARCHAR;

It should be:

CREATE TABLE IF NOT EXISTS MyTab (
    Month INT(2),
    Date INT(2),
    Year INT(4),
    Event VARCHAR
)

Also, note that the query doesn't need to end with a ;, as mentioned in the docs:

Parameters
sql the SQL statement to be executed. Multiple statements separated by semicolons are not supported.

Also, you should ALWAYS check your LogCat output, since this should throw a SQLiteException.

Some further SQLite notes:

SQLite doesn't have a VARCHAR-type. It only has TEXT and will convert any text-like type into it.
Note that giving a length for a datatype is also ignored by SQLite:

SQLite does not impose any length restrictions (other than the large global SQLITE_MAX_LENGTH limit) on the length of strings, BLOBs or numeric values.

来源：https://stackoverflow.com/questions/13893473/how-to-create-table-using-sqlite-database-in-android

标签

android

database

android-sqlite