Android批量插入數據
Android中在sqlite插入數據的時候默認一條語句就是一個事務(All individual SQL Statements, (with rare exceptions like Bulk Inserts with No Log, or Truncate Table) are automaticaly "In a Transaction" whether you explicitly say so or not.. (even if they insert, update, or delete millions of rows).)，因此如果存在上萬條數據插入的話，那就需要執行上萬次插入操作，操作速度可想而知。因此在Android中插入數據時，使用批量插入的方式可以大大提高插入速度。
批量插入的模板如下：
- public void inertOrUpdateDateBatch(List<String> sqls) {
- SQLiteDatabase db = getWritableDatabase();
- db.beginTransaction();
- try {
- for (String sql : sqls) {
- db.execSQL(sql);
- }
- // 設置事務標志為成功，當結束事務時就會提交事務
- db.setTransactionSuccessful();
- } catch (Exception e) {
- e.printStackTrace();
- } finally {
- // 結束事務
- db.endTransaction();
- db.close();
- }
- }
注意此處的：
- db.execSQL(sql);
官方的API顯示：
public void execSQL (String sql)
Execute a single SQL statement that is NOT a SELECT or any other SQL statement that returns data.
It has no means to return any data (such as the number of affected rows). Instead, you're encouraged to use insert(String, String, ContentValues), update(String, ContentValues, String, String[]), et al, when possible.
When using enableWriteAheadLogging(), journal_mode is automatically managed by this class. So, do not set journal_mode using "PRAGMA journal_mode'" statement if your app is using enableWriteAheadLogging()
Parameters
| sql | the SQL statement to be executed. Multiple statements separated by semicolons are not supported. |
|---|
Throws
| SQLException | if the SQL string is invalid |
|---|
說明，每次執行SQL只能有一條語句。在執行的時候，不能寫成：
- insert into student values('yang','boy');insert into student values('zhou','girl');
形式，而需要將兩條SQL語句拆開，每條SQL語句執行一次。
