Android SQLite: should I use beginTransaction and endTransaction only at insert or both insert and read...
ATM when I write to the SQLite in my android app, I do it this way:
try {
for (User user: users) {
ContentValues values = new ContentValues();
databaseManager.database.beginTransaction();
values.put("user_name", user.getName());
values.put("user_email", user.getEmail());
databaseManager.database.insert("users", null, values);
}
databaseManager.database.setTransactionSuccessful();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
databaseManager.database.endTransaction();
}
But when I read from the DB, I dont use begin, setsuccessful and end:
Cursor cursor = databaseManager.database.rawQuery(SQLQueries.getUsers(), null);
if (cursor.moveToFirst()) {
if (cursor!=null) {
do {
User user = new User();
try {
user.setName(cursor.getString(cursor.getColumnIndexOrThrow("user_name")));
user.setEmail(cursor.getString(cursor.getColumnIndexOrThrow("user_email")));
} catch (Exception ex) {
ex.printStackTrace();
}
users.add(user);
} while (cursor.moveToNext());
}
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
cursor = null;
}
Should I add beginTransaction, setTransactionSuccessful and endTransaction to the read operations as well? Im pretty sure I shouldnt, but I need to be 100% on this one.
add a comment |
ATM when I write to the SQLite in my android app, I do it this way:
try {
for (User user: users) {
ContentValues values = new ContentValues();
databaseManager.database.beginTransaction();
values.put("user_name", user.getName());
values.put("user_email", user.getEmail());
databaseManager.database.insert("users", null, values);
}
databaseManager.database.setTransactionSuccessful();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
databaseManager.database.endTransaction();
}
But when I read from the DB, I dont use begin, setsuccessful and end:
Cursor cursor = databaseManager.database.rawQuery(SQLQueries.getUsers(), null);
if (cursor.moveToFirst()) {
if (cursor!=null) {
do {
User user = new User();
try {
user.setName(cursor.getString(cursor.getColumnIndexOrThrow("user_name")));
user.setEmail(cursor.getString(cursor.getColumnIndexOrThrow("user_email")));
} catch (Exception ex) {
ex.printStackTrace();
}
users.add(user);
} while (cursor.moveToNext());
}
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
cursor = null;
}
Should I add beginTransaction, setTransactionSuccessful and endTransaction to the read operations as well? Im pretty sure I shouldnt, but I need to be 100% on this one.
add a comment |
ATM when I write to the SQLite in my android app, I do it this way:
try {
for (User user: users) {
ContentValues values = new ContentValues();
databaseManager.database.beginTransaction();
values.put("user_name", user.getName());
values.put("user_email", user.getEmail());
databaseManager.database.insert("users", null, values);
}
databaseManager.database.setTransactionSuccessful();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
databaseManager.database.endTransaction();
}
But when I read from the DB, I dont use begin, setsuccessful and end:
Cursor cursor = databaseManager.database.rawQuery(SQLQueries.getUsers(), null);
if (cursor.moveToFirst()) {
if (cursor!=null) {
do {
User user = new User();
try {
user.setName(cursor.getString(cursor.getColumnIndexOrThrow("user_name")));
user.setEmail(cursor.getString(cursor.getColumnIndexOrThrow("user_email")));
} catch (Exception ex) {
ex.printStackTrace();
}
users.add(user);
} while (cursor.moveToNext());
}
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
cursor = null;
}
Should I add beginTransaction, setTransactionSuccessful and endTransaction to the read operations as well? Im pretty sure I shouldnt, but I need to be 100% on this one.
ATM when I write to the SQLite in my android app, I do it this way:
try {
for (User user: users) {
ContentValues values = new ContentValues();
databaseManager.database.beginTransaction();
values.put("user_name", user.getName());
values.put("user_email", user.getEmail());
databaseManager.database.insert("users", null, values);
}
databaseManager.database.setTransactionSuccessful();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
databaseManager.database.endTransaction();
}
But when I read from the DB, I dont use begin, setsuccessful and end:
Cursor cursor = databaseManager.database.rawQuery(SQLQueries.getUsers(), null);
if (cursor.moveToFirst()) {
if (cursor!=null) {
do {
User user = new User();
try {
user.setName(cursor.getString(cursor.getColumnIndexOrThrow("user_name")));
user.setEmail(cursor.getString(cursor.getColumnIndexOrThrow("user_email")));
} catch (Exception ex) {
ex.printStackTrace();
}
users.add(user);
} while (cursor.moveToNext());
}
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
cursor = null;
}
Should I add beginTransaction, setTransactionSuccessful and endTransaction to the read operations as well? Im pretty sure I shouldnt, but I need to be 100% on this one.
edited Nov 10 at 22:57
Vergiliy
268
268
asked Jul 14 '14 at 7:29
J. K.
6,0801461135
6,0801461135
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
When you are not using explicit transactions, SQLite will automatically wrap a transaction around every statement.
When you write to the database, every insert/update/delete call is a single statement.
If you are doing multiple such operations, you use transactions to avoid paying the transaction overhead for each of them.
A query (query or rawQuery) is a single statement, even if it returns multiple rows.
Therefore, using a transaction around a single query does not make any difference.
(If you have multiple queries, you could use a transaction to ensure that their results are consistent with each other even if another thread attempts to change the database between them.)
so If I have multiple reads, I should wrap them all in a begin/set/end transaction?
– J. K.
Jul 14 '14 at 8:04
That depends on whether you need them to be atomic.
– CL.
Jul 14 '14 at 8:13
I see, thanks :)
– J. K.
Jul 14 '14 at 8:22
1
More, since a query doesn't modify the database contents, including it in a transaction would be meaningless. So use transactions for commands, multiple ones: should they succeed or fail all together.
– Fantômas
Jul 14 '14 at 15:26
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
When you are not using explicit transactions, SQLite will automatically wrap a transaction around every statement.
When you write to the database, every insert/update/delete call is a single statement.
If you are doing multiple such operations, you use transactions to avoid paying the transaction overhead for each of them.
A query (query or rawQuery) is a single statement, even if it returns multiple rows.
Therefore, using a transaction around a single query does not make any difference.
(If you have multiple queries, you could use a transaction to ensure that their results are consistent with each other even if another thread attempts to change the database between them.)
so If I have multiple reads, I should wrap them all in a begin/set/end transaction?
– J. K.
Jul 14 '14 at 8:04
That depends on whether you need them to be atomic.
– CL.
Jul 14 '14 at 8:13
I see, thanks :)
– J. K.
Jul 14 '14 at 8:22
1
More, since a query doesn't modify the database contents, including it in a transaction would be meaningless. So use transactions for commands, multiple ones: should they succeed or fail all together.
– Fantômas
Jul 14 '14 at 15:26
add a comment |
When you are not using explicit transactions, SQLite will automatically wrap a transaction around every statement.
When you write to the database, every insert/update/delete call is a single statement.
If you are doing multiple such operations, you use transactions to avoid paying the transaction overhead for each of them.
A query (query or rawQuery) is a single statement, even if it returns multiple rows.
Therefore, using a transaction around a single query does not make any difference.
(If you have multiple queries, you could use a transaction to ensure that their results are consistent with each other even if another thread attempts to change the database between them.)
so If I have multiple reads, I should wrap them all in a begin/set/end transaction?
– J. K.
Jul 14 '14 at 8:04
That depends on whether you need them to be atomic.
– CL.
Jul 14 '14 at 8:13
I see, thanks :)
– J. K.
Jul 14 '14 at 8:22
1
More, since a query doesn't modify the database contents, including it in a transaction would be meaningless. So use transactions for commands, multiple ones: should they succeed or fail all together.
– Fantômas
Jul 14 '14 at 15:26
add a comment |
When you are not using explicit transactions, SQLite will automatically wrap a transaction around every statement.
When you write to the database, every insert/update/delete call is a single statement.
If you are doing multiple such operations, you use transactions to avoid paying the transaction overhead for each of them.
A query (query or rawQuery) is a single statement, even if it returns multiple rows.
Therefore, using a transaction around a single query does not make any difference.
(If you have multiple queries, you could use a transaction to ensure that their results are consistent with each other even if another thread attempts to change the database between them.)
When you are not using explicit transactions, SQLite will automatically wrap a transaction around every statement.
When you write to the database, every insert/update/delete call is a single statement.
If you are doing multiple such operations, you use transactions to avoid paying the transaction overhead for each of them.
A query (query or rawQuery) is a single statement, even if it returns multiple rows.
Therefore, using a transaction around a single query does not make any difference.
(If you have multiple queries, you could use a transaction to ensure that their results are consistent with each other even if another thread attempts to change the database between them.)
answered Jul 14 '14 at 7:57
CL.
134k12120153
134k12120153
so If I have multiple reads, I should wrap them all in a begin/set/end transaction?
– J. K.
Jul 14 '14 at 8:04
That depends on whether you need them to be atomic.
– CL.
Jul 14 '14 at 8:13
I see, thanks :)
– J. K.
Jul 14 '14 at 8:22
1
More, since a query doesn't modify the database contents, including it in a transaction would be meaningless. So use transactions for commands, multiple ones: should they succeed or fail all together.
– Fantômas
Jul 14 '14 at 15:26
add a comment |
so If I have multiple reads, I should wrap them all in a begin/set/end transaction?
– J. K.
Jul 14 '14 at 8:04
That depends on whether you need them to be atomic.
– CL.
Jul 14 '14 at 8:13
I see, thanks :)
– J. K.
Jul 14 '14 at 8:22
1
More, since a query doesn't modify the database contents, including it in a transaction would be meaningless. So use transactions for commands, multiple ones: should they succeed or fail all together.
– Fantômas
Jul 14 '14 at 15:26
so If I have multiple reads, I should wrap them all in a begin/set/end transaction?
– J. K.
Jul 14 '14 at 8:04
so If I have multiple reads, I should wrap them all in a begin/set/end transaction?
– J. K.
Jul 14 '14 at 8:04
That depends on whether you need them to be atomic.
– CL.
Jul 14 '14 at 8:13
That depends on whether you need them to be atomic.
– CL.
Jul 14 '14 at 8:13
I see, thanks :)
– J. K.
Jul 14 '14 at 8:22
I see, thanks :)
– J. K.
Jul 14 '14 at 8:22
1
1
More, since a query doesn't modify the database contents, including it in a transaction would be meaningless. So use transactions for commands, multiple ones: should they succeed or fail all together.
– Fantômas
Jul 14 '14 at 15:26
More, since a query doesn't modify the database contents, including it in a transaction would be meaningless. So use transactions for commands, multiple ones: should they succeed or fail all together.
– Fantômas
Jul 14 '14 at 15:26
add a comment |
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