当前位置： 移动技术网 > IT编程>移动开发>Android > Android实现创建或升级数据库时执行语句

Android实现创建或升级数据库时执行语句

2019年07月24日  | 移动技术网IT编程  | 我要评论

复方金荞麦颗粒,陈晓东结婚,绝地悍将修改器

本文实例讲述了android创建或升级数据库时执行的语句，如果是创建或升级数据库，请使用带list参数的构造方法，带sql语句的构造方法将在数据库创建或升级时执行。

具体程序代码如下：

import java.util.list;
import android.content.context;
import android.database.sqlite.sqlitedatabase;
import android.database.sqlite.sqlitedatabase.cursorfactory;
import android.database.sqlite.sqliteopenhelper;
public class simplesqliteopenhelper extends sqliteopenhelper {
 private static final int init_version = 1;
 /**
 * 创建或升级数据库时执行的语句。
 */
 private list<string> sqlstatementexed;
 /**
 * 如果是创建或升级数据库，请使用带list参数的构造方法。
 * 
 * @param context
 *      to use to open or create the database
 * @param name
 *      of the database file, or null for an in-memory database
 * @param factory
 *      to use for creating cursor objects, or null for the default
 * @param version
 *      number of the database (starting at 1); if the database is
 *      older, onupgrade(sqlitedatabase, int, int) will be used to
 *      upgrade the database; if the database is newer,
 *      ondowngrade(sqlitedatabase, int, int) will be used to
 *      downgrade the database
 */
 public simplesqliteopenhelper(context context, string name,
  cursorfactory factory, int version) {
 super(context, name, factory, version);
 sqlstatementexed = null;
 }
 /**
 * 带sql语句的构造方法。此sql语句将在数据库创建或升级时执行。
 * 
 * @param context
 *      to use to open or create the database
 * @param name
 *      of the database file, or null for an in-memory database
 * @param factory
 *      to use for creating cursor objects, or null for the default
 * @param version
 *      number of the database (starting at 1); if the database is
 *      older, onupgrade(sqlitedatabase, int, int) will be used to
 *      upgrade the database; if the database is newer,
 *      ondowngrade(sqlitedatabase, int, int) will be used to
 *      downgrade the database
 * @param sqlstatementexed
 *      在数据库创建或升级的时候将执行的语句。
 */
 public simplesqliteopenhelper(context context, string name,
  cursorfactory factory, int version, list<string> sqlstatementexed) {
 super(context, name, factory, version);
 this.sqlstatementexed = sqlstatementexed;
 }
 /**
 * 如果是创建或升级数据库，请使用带list参数的构造方法。
 * @param context
 *      to use to open or create the database
 * @param name
 *      of the database file, or null for an in-memory database
 * @param version
 *      number of the database (starting at 1); if the database is
 *      older, onupgrade(sqlitedatabase, int, int) will be used to
 *      upgrade the database; if the database is newer,
 *      ondowngrade(sqlitedatabase, int, int) will be used to
 *      downgrade the database
 */
 public simplesqliteopenhelper(context context, string name, int version) {
 super(context, name, null, version);
 sqlstatementexed = null;
 }
 /**
 * 如果是创建或升级数据库，请使用带list参数的构造方法。
 * @param context
 *      to use to open or create the database
 * @param name
 *      of the database file, or null for an in-memory database
 */
 public simplesqliteopenhelper(context context, string name) {
 super(context, name, null, init_version);
 sqlstatementexed = null;
 }
 /**
 * 如果是创建或升级数据库，请使用带list参数的构造方法。
 * 
 * @param context
 *      to use to open or create the database
 * @param name
 *      of the database file, or null for an in-memory database
 * @param version
 *      number of the database (starting at 1); if the database is
 *      older, onupgrade(sqlitedatabase, int, int) will be used to
 *      upgrade the database; if the database is newer,
 *      ondowngrade(sqlitedatabase, int, int) will be used to
 *      downgrade the database
 * @param sqlcreatestatement
 *      在创建或升级数据库时要执行的语句。
 */
 public simplesqliteopenhelper(context context, string name, int version,
  list<string> sqlcreatestatement) {
 super(context, name, null, version);
 this.sqlstatementexed = sqlcreatestatement;
 }
 /**
 * @param context
 * @param name
 * @param sqlcreatestatement
 *      在创建或升级数据库时要执行的语句。
 */
 public simplesqliteopenhelper(context context, string name,
  list<string> sqlcreatestatement) {
 super(context, name, null, init_version);
 this.sqlstatementexed = sqlcreatestatement;
 }
 /*
 * (non-javadoc)
 * @see
 * android.database.sqlite.sqliteopenhelper#oncreate(android.database.sqlite
 * .sqlitedatabase)
 */
 @override
 @deprecated
 public void oncreate(sqlitedatabase db) {
 exesqlstatementexed(db);
 }
 /*
 * (non-javadoc)
 * @see
 * android.database.sqlite.sqliteopenhelper#onupgrade(android.database.sqlite
 * .sqlitedatabase, int, int)
 */
 @override
 @deprecated
 public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {
 if (newversion > oldversion) {
  exesqlstatementexed(db);
 }
 }
 /**
 * 初始化或升级数据库时执行的sql语句。。
 */
 private void exesqlstatementexed(sqlitedatabase db) {
 if (sqlstatementexed != null) {
  for (string statement : sqlstatementexed) {
  db.execsql(statement);
  }
 }
 }
}

希望本文所述方法对于大家进行android程序开发能够起到一定的帮助作用。

您可能感兴趣的文章:

如对本文有疑问，请在下面进行留言讨论，广大热心网友会与你互动！！ 点击进行留言回复

相关文章:

验证码：
最近更新的文章
大家感兴趣的文章
移动技术网