on Upgrade SQLiteDatabase table - Android Database

Android examples for Database:SQL Update

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Description

on Upgrade SQLiteDatabase table

Demo Code


import java.util.List;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

public class Main{
    private static final String TAG = TableUtil.class.getSimpleName();
    /**//from ww  w . j a va  2 s  .c  o  m
     * 
     * @param database
     * @param oldVersion
     * @param newVersion
     * @param table
     * @param createString
     * @param columnInfo
     *            - your substring of your create table string, the part where
     *            you initialize the columns. Eg
     *            "(_id integer primary key, chat text, lat real, lon real)".
     *            Please include the ().
     */
    public static void onUpgrade(SQLiteDatabase database, int oldVersion,
            int newVersion, String table, String columnInfo) {
        Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                + newVersion);

        // NOTE: the below does not handle table downgrades.
        // http://stackoverflow.com/questions/3505900/sqliteopenhelper-onupgrade-confusion-android

        database.beginTransaction();

        // when doing an upgrade, this table might not exist, so make it if it
        // doesn't
        database.execSQL("CREATE TABLE IF NOT EXISTS " + table + columnInfo);

        // get the columns of the current table.
        List<String> columns = DbUtil.GetColumns(database, table);

        String tempTableString = table + "_temp";

        // backup table
        database.execSQL("ALTER TABLE " + table + " RENAME TO "
                + tempTableString);

        // Create table with new schema
        database.execSQL("CREATE TABLE " + table + columnInfo);

        // get all of the columns from the old table still in the new table.
        columns.retainAll(DbUtil.GetColumns(database, table));

        // restore data from old table into new table.
        String cols = DbUtil.join(columns, ",");
        database.execSQL(String.format(
                "INSERT INTO %s (%s) SELECT %s from %s", table, cols, cols,
                tempTableString));

        // remove the temporary table
        database.execSQL("DROP TABLE IF EXISTS " + tempTableString);

        database.setTransactionSuccessful();
        database.endTransaction();

    }
}

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