1. DELETE is a DML Command.
2. DELETE statement is executed using a row lock, each row in the table is locked for deletion.
3. We can specify filters in where clause
4. It deletes specified data if where condition exists.
5. Delete activates a trigger because the operation are logged individually.
6. Slower than truncate because, it keeps logs.
7. Rollback is possible.
TRUNCATE
1. TRUNCATE is a DDL command.
2. TRUNCATE TABLE always locks the table and page but not each row.
3. Cannot use Where Condition.
4. It Removes all the data.
5. TRUNCATE TABLE cannot activate a trigger because the operation does not log individual row deletions.
6. Faster in performance wise, because it doesn't keep any logs.
7. Rollback is not possible.
TRUNCATE
1. TRUNCATE is a DDL command.
2. TRUNCATE TABLE always locks the table and page but not each row.
3. Cannot use Where Condition.
4. It Removes all the data.
5. TRUNCATE TABLE cannot activate a trigger because the operation does not log individual row deletions.
6. Faster in performance wise, because it doesn't keep any logs.
7. Rollback is not possible.
Deletes the data as well as structure.
The difference b/w DROP and DELETE table is that, after executing DELETE statement the contents of table are removed but the structure remains same, but in case of DROP statement both the contents and structure are removed.
How ASP.NET different from ASP?
2. DELETE statement is executed using a row lock, each row in the table is locked for deletion.
3. We can specify filters in where clause
4. It deletes specified data if where condition exists.
5. Delete activates a trigger because the operation are logged individually.
6. Slower than truncate because, it keeps logs.
7. Rollback is possible.
TRUNCATE
1. TRUNCATE is a DDL command.
2. TRUNCATE TABLE always locks the table and page but not each row.
3. Cannot use Where Condition.
4. It Removes all the data.
5. TRUNCATE TABLE cannot activate a trigger because the operation does not log individual row deletions.
6. Faster in performance wise, because it doesn't keep any logs.
7. Rollback is not possible.
TRUNCATE
1. TRUNCATE is a DDL command.
2. TRUNCATE TABLE always locks the table and page but not each row.
3. Cannot use Where Condition.
4. It Removes all the data.
5. TRUNCATE TABLE cannot activate a trigger because the operation does not log individual row deletions.
6. Faster in performance wise, because it doesn't keep any logs.
7. Rollback is not possible.
Deletes the data as well as structure.
The difference b/w DROP and DELETE table is that, after executing DELETE statement the contents of table are removed but the structure remains same, but in case of DROP statement both the contents and structure are removed.
How ASP.NET different from ASP?
Difference b/w
Delete, Truncate, Drop Click here :-
DELETE
Drop
· Asp.Net
forms have a code behind file which contains all event handling code But in Asp
it doesn't have such facility to separate programming logic form design.
· Asp.Net
inherits the class written in code behind But in Asp does not have concept
of inheritance
· Asp.Net
use full fledged programming language But Asp it use scripting language.
· Asp.Net
web application are configuration(web.config) But in Asp there are
not.
Difference
B/w Primary key and Unique key.
· Primary
key is only one in a table but unique key can be more then one.
· primary
key does not have null value but unique can have one null value.
· primary
key is by default clustered index but unique is by default non-clustered index.
· primary
key has reference key in another table and unique key also has reference
key in another table.
Clustered
index and non clustered index
clustered
index is index in with row set are stored in particular format but in
non clustered index then is not format.
Difference
B/w Primary key and Foreign key.
· Primary
key is a unique in table this is only one in a table but primary can be define
more then one.
· primary
key does not have null value but Foreign key have null value.
· primary
key is by default clustered index.
Difference B/w ADO and ADO.NET
§ In ADO
we have record set and in ADO.NET we have Dataset.
§ In
recordset we can only have one table. If we want to accommodate more than one
tables we need to do inner join and fill the recordset.
§ Dataset
can have multiple tables.
§ All
data persist in XML as compared to classic ADO where data persisted in Binary
format also.
§ In ADO
we have record set and in ADO.NET we have Dataset.
§ In
recordset we can only have one table. If we want to accommodate more than one
tables we need to do inner join and fill the recordset.
§ Dataset
can have multiple tables.
§ All
data persist in XML as compared to classic ADO where data persisted in Binary
format also.
The difference b/w Data Set and
Data Reader
§ Data
Reader provides forward only and read only access to data, while the Data set
objects can hold more than one table from the same data source as well as the
relationships between them.
§ Dataset
is a disconnected architecture while data reader is connected architecture.
§ Dataset
can persist contents while data reader cannot persist contents they are forward
only.
Difference B/w Data Set & Record set
There are two main differences are :
§ Dataset you
an retrieve data from two databases like oracle and sql server and merge them
in one dataset.
§ Recordset this
is not possible
§ All
representation of Dataset is using XML while recordset uses COM.
§ Recordset
can not be transmitted on HTTP while Dataset can be.
Difference B/w DataAdepter and
Datareader.
SqlDataReader:
· Holds
the connection open until you are finished (don't forget to close it!).
· Can
typically only be iterated over once
· Is not
as useful for updating back to the database
On the other hand, it:
· Only
has one record in memory at a time rather than an entire result set (this can
be huge)
· Is
about as fast as it you can get for that one iteration
· Allows
you start processing results sooner
SqlDataAdapter/DataSet
· Lets
you close the connection as soon it's done loading data, and may even close it
for you automatically
· All of
the results are available in memory
· You
can iterate over it as many times as you need, or even look up a specific
record by index
· Has
some built-in faculties for updating back to the database
At the cost of:
· Much higher
memory use
· You
wait until all the data is loaded before using any of it
Abstract Class V/s Interface
· Abstract
class can have implementation for some of its method. But the
interface can't have implementation for any of its method.
· Abstract
class can have field but interface does not have fields.
· An
Interface can inherit from another interface only can't inherit from another
abstract class but an abstract class can inherit from another abstract class
and another interface.
· Abstract
class members can have access modifiers where interface member doesn't have
access modifiers.
Structure V/s Class
· Class
is a reference type so it is stored in Heap. Structure is value type so it is
stored in stack.
· class
has inheritance but structure does not has inheritance.
· In
class there is constructor But in structure there may be or may not
be constructor.
· By
default class has private access modifier and structure has public
modifier.
