Android中如何根据sql文件创建数据库并插入数据

注：本人转载，如原文作者看到十分抱歉！同时也十分感谢！

因为在开发客户端的时候，服务器端的有写数据是重复的，不需要再去访问服务器的，然后服务器端提供的是一个sql文件，里面包含了数据库和数据，我们这些开发客户端的不可能一行一行的进行手动入库吧？所以我就想到了直接读取sql文件进行创建数据并插入数据好了。

创建DBHelp并继承SQLiteOpenHelper

public class DBHelper extends SQLiteOpenHelper {

private Context mContext;

public DBHelper(Context context, String databaseName,
CursorFactory factory, int version) {
super(context, databaseName, factory, version);
mContext = context;
}

/**
* 数据库第一次创建时调用
* */
@Override
public void onCreate(SQLiteDatabase db) {
if (!tabIsExist("test", db)) {
executeAssetsSQL(db, "test.sql");
// db.execSQL(sql);
//System.out.println("创建表");
}
}

/**
* 数据库升级时调用
* */
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// 数据库不升级
if (newVersion <= oldVersion) {
return;
}
Configuration.oldVersion = oldVersion;

int changeCnt = newVersion - oldVersion;
for (int i = 0; i < changeCnt; i++) {
// 依次执行updatei_i+1文件 由1更新到2 [1-2]，2更新到3 [2-3]
String schemaName = "update" + (oldVersion + i) + "_"
+ (oldVersion + i + 1) + ".sql";
executeAssetsSQL(db, schemaName);
}
}

/**
* 读取数据库文件（.sql），并执行sql语句
* */
private void executeAssetsSQL(SQLiteDatabase db, String schemaName) {
BufferedReader in = null;
try {
in = new BufferedReader(new InputStreamReader(mContext.getAssets()
.open(Configuration.DB_PATH + "/" + schemaName)));

//System.out.println("路径:" + Configuration.DB_PATH + "/" + schemaName);
String line;
String buffer = "";
while ((line = in.readLine()) != null) {
buffer += line;
if (line.trim().endsWith(";")) {
db.execSQL(buffer.replace(";", ""));
buffer = "";
}
}
} catch (IOException e) {
Log.e("db-error", e.toString());
} finally {
try {
if (in != null)
in.close();
} catch (IOException e) {
Log.e("db-error", e.toString());
}
}
}

public List selectAllCities(SQLiteDatabase db) {
List areas = new ArrayList();
Area area;
String sql = "select * from test where area_level=?";
Cursor cursor = db.rawQuery(sql, new String[] { "" + 0 });

while(cursor.moveToNext()){
area = new Area();
area.setId(cursor.getInt(0));
area.setArea_name(cursor.getString(2));
areas.add(area);
area = null;
}
cursor.close();

return areas;
}

public List selectAllAreas(SQLiteDatabase db,int parent_id) {
List areas = new ArrayList();
Area area;
String sql = "select * from test where parent_id=?";
Cursor cursor = db.rawQuery(sql, new String[] { "" + parent_id });

while(cursor.moveToNext()){
area = new Area();
area.setId(cursor.getInt(0));
area.setArea_name(cursor.getString(2));
areas.add(area);
area = null;
}
cursor.close();

return areas;
}

/**
* 判断是否存在某一张表
* @param tabName
* @param db
* @return
*/
public boolean tabIsExist(String tabName, SQLiteDatabase db) {
boolean result = false;
if (tabName == null) {
return false;
}
Cursor cursor = null;
try {
String sql = "select count(*) as c from sqlite_master where type ='table' and name ='" + tabName.trim() + "' ";
cursor = db.rawQuery(sql, null);
if (cursor.moveToNext()) {
int count = cursor.getInt(0);
if (count > 0) {
result = true;
}
}

} catch (Exception e) {
}
return result;
}

}

Configuration.java是一些常量

public class Configuration {
public static final String DB_PATH = "schema";
public static final String DB_NAME = "test.db";
public static final int DB_VERSION = 1;
public static int oldVersion = -1;

}

其实这个过程非常的简单易懂，就是根据路径去读取文件，然后读取文件里面的内容，再根据关键字，sqllite会自动进行相应的操作，所以这个sql文件中的sql语句一定要规范，不然会写入不了的。

在activity中调用：

dbHelper = new DBHelper(this, "test", null, 1);

dbHelper.onCreate(dbHelper.getWritableDatabase());