Android实现创建或升级数据库时执行语句

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。