Why do we use restrict qualifier in C++?

Abhinanda Shri
Updated on 30-Jul-2019 22:30:21

344 Views

There's no such keyword in C++. List of C++ keywords can be found in section 2.11/1 of C++ language standard. restrict is a keyword in the C99 version of C language and not in C++.In C, A restrict-qualified pointer (or reference) is basically a promise to the compiler that for the scope of the pointer, the target of the pointer will only be accessed through that pointer (and pointers copied from it).C++ compilers also support this definition for optimization purposes, but it is not a part of the official language specification.

How can we add a FOREIGN KEY constraint to the field of an existing MySQL table?

Ankitha Reddy
Updated on 30-Jul-2019 22:30:21

2K+ Views

We can add a FOREIGN KEY constraint to a column of an existing MySQL table with the help of ALTER TABLE statement. Syntax ALTER TABLE table_name ADD FOREIGN KEY (colum_name) REFERENCES table having Primary Key(column_name); Example Suppose we want to add a FOREIGN KEY constraint on the table ‘Orders1’ referencing to the table ‘Customer’ which have column ‘Cust_Id’ as the Primary Key. It can be done with the help of the following query − mysql> Alter table orders1 add FOREIGN KEY(Cust_id) REFERENCES Customer(Cust_id); Query OK, 0 rows affected (0.21 sec) Records: 0  Duplicates: 0  Warnings: 0   mysql> ... Read More

What happens to MySQL temporary tables if MySQL session is ended?

seetha
Updated on 30-Jul-2019 22:30:21

202 Views

Temporary table would be deleted if MySQL session terminates. After login again, on issuing the SELECT command we will find no data available in the database. Even our temporary table will not exist.

The auto storage class in C++

Jennifer Nicholas
Updated on 30-Jul-2019 22:30:21

298 Views

In C, The auto storage class specifier lets you explicitly declare a variable with automatic storage. The auto storage class is the default for variables declared inside a block. A variable x that has automatic storage is deleted when the block in which x was declared exits.You can only apply the auto storage class specifier to names of variables declared in a block or to names of function parameters. However, these names by default have automatic storage. Therefore the storage class specifier auto is usually redundant in a data declaration.It was initially carried over to C++ for syntactical compatibility only, ... Read More

How do we compare String in Java

Giri Raju
Updated on 30-Jul-2019 22:30:21

313 Views

https://www.tutorialspoint.com/javaexamples/string_compare.htm

How to concatenate lists in java?

Abhinanda Shri
Updated on 30-Jul-2019 22:30:21

741 Views

The addAll(Collection

What is the difference between the size of ArrayList and length of Array in Java?

Srinivas Gorla
Updated on 30-Jul-2019 22:30:21

2K+ Views

ArrayList doesn't have length() method, the size() method of ArrayList provides the number of objects available in the collection.Array has length property which provides the length or capacity of the Array. It is the total space allocated during the initialization of the array.

How can I fetch the value of REPLACE() function in the column name of our choice?

Ankitha Reddy
Updated on 30-Jul-2019 22:30:21

160 Views

For fetching the values of REPLACE() function in our choice column name, we need to use the keyword ‘AS’ with REPLACE() function. Example mysql> Select Name, REPLACE(Name, 'G','S') AS Name_Changed from student Where Subject = 'Computers'; +--------+--------------+ | Name | Name_Changed | +--------+--------------+ | Gaurav | Saurav | | Gaurav | Saurav | +--------+--------------+ 2 rows in set (0.00 sec) The query above will give the result set of REPLACE() function in column name of our choice ‘Name_Changed’ which is given after keyword ‘AS’.

how to convert Object array to String array in java

Sai Nath
Updated on 30-Jul-2019 22:30:21

5K+ Views

As list.toArray() returns an Object[], it can be converted to String array by passing the String[] as parameter. See the example below.import java.util.ArrayList; import java.util.List; public class Tester { public static void main(String[] args) { List data = new ArrayList(); data.add("A"); data.add("B"); data.add("C"); //Object[] objects = data.toArray(); String[] strObjects = data.toArray(new String[0]); for(String obj: strObjects) { System.out.println(obj); } } }OutputA B C

How can we remove FOREIGN KEY constraint from a column of an existing MySQL table?

George John
Updated on 30-Jul-2019 22:30:21

11K+ Views

We can remove FOREIGN KEY constraint from a column of an existing table by using DROP keyword along with ALTER TABLE statement. Syntax ALTER TABLE table_name DROP FOREIGN KEY constraint_name Here constraint name is the name of foreign key constraint which we applied while creating the table. If no constraint name is specified then MySQL will provide constraint name which can be checked by SHOW CREATE TABLE statement. Example The following query will delete the FOREIGN KEY constraint from ‘orders’ table − mysql> Alter table orders DROP FOREIGN KEY orders_ibfk_1; Query OK, 0 rows affected (0.22 sec) ... Read More

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