Delete table from database by class associated with class.Class must be marked by DatabaseTable annotation. - Android Database

Android examples for Database:Table Drop

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Description

Delete table from database by class associated with class.Class must be marked by DatabaseTable annotation.

Demo Code


import android.database.sqlite.SQLiteDatabase;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Date;

public class Main{
    /**/* w ww .ja  v a 2 s . co m*/
     * Delete table from db by class associated with class.Class must be marked
     * by {@link DatabaseTable} annotation.
     * 
     * @param db
     * @param mappedClass
     */
    public static void deleteTable(SQLiteDatabase db, Class<?> mappedClass) {
        if (db == null) {
            throw new IllegalArgumentException("db should not be null");
        }

        String sql = deleteTableQuery(mappedClass);
        db.execSQL(sql);
    }
    /**
     * Delete table from db by class associated with class.Class must be marked
     * by {@link DatabaseTable} annotation.
     *
     * @param mappedClass
     */
    public static String deleteTableQuery(Class<?> mappedClass) {
        if (mappedClass == null) {
            throw new IllegalArgumentException(
                    "mappedClass should not be null");
        }

        String tableName = getTableName(mappedClass);

        return "DROP TABLE IF EXISTS " + tableName;
    }
    /**
     * Get name of table by class marked {@link DatabaseTable} annotation.
     * 
     * @param mappedClass
     * @return - name of class.
     */
    public static String getTableName(Class<?> mappedClass) {
        if (mappedClass == null) {
            throw new NullPointerException(
                    "\"mappedClass\" should not be null");
        }
        DatabaseTable classAnnotation = mappedClass
                .getAnnotation(DatabaseTable.class);
        if (classAnnotation == null) {
            throw new IllegalArgumentException(
                    "Class mut be marked by DatabaseTable anatation");
        }

        String tableName = classAnnotation.name();
        if (tableName == null || tableName.length() <= 0) {
            tableName = mappedClass.getSimpleName();
        }
        return tableName;
    }
}

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