Add Values of Two Columns Considering Null Values as Zero in MySQL

Sharon Christine
Updated on 30-Jun-2020 15:00:17

912 Views

For this, use COALESCE() function from MySQL. Let us first create a table −mysql> create table DemoTable -> ( -> Value1 int, -> Value2 int -> ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 200); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values(NULL, 90); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(NULL, NULL); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(600, NULL); Query OK, 1 row affected (0.12 sec)Display all records from ... Read More

Use peekLast in Android LinkedBlockingDeque

karthikeya Boyini
Updated on 30-Jun-2020 14:59:22

127 Views

Before getting into an example, we should know what LinkedBlockingDeque is. It is implemented by Collection interface and the AbstractQueue class. It provides optional boundaries based on linked nodes.It going to pass memory size to a constructor and helps to provide memory wastage in android.This example demonstrates about How to use peekLast() in android LinkedBlockingDequeStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, we have taken a text ... Read More

Count Occurrences of a Specific Word in MySQL Column

Sharon Christine
Updated on 30-Jun-2020 14:59:08

1K+ Views

For this, you can use COUNT() function. Let us first create a table −mysql> create table DemoTable    -> (    -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> EmployeeName varchar(100)    -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(EmployeeName) values('John'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable(EmployeeName) values('Carol'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(EmployeeName) values('David'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(EmployeeName) values('Carol'); Query OK, 1 row affected ... Read More

Use peekLast in Android ConcurrentLinkedDeque

Samual Sam
Updated on 30-Jun-2020 14:58:49

147 Views

Before getting into an example, we should know what ConcurrentLinkedDeque is, it is unbounded deque based on linked nodes. Multiple threads can access deque elements with safety.This example demonstrates about How to use peekLast() in android ConcurrentLinkedDequeStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, we have taken a text view to show ConcurrentLinkedDeque elements.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.os.Build; import android.os.Bundle; ... Read More

Use peekFirst in Android LinkedBlockingDeque

karthikeya Boyini
Updated on 30-Jun-2020 14:58:20

133 Views

Before getting into an example, we should know what LinkedBlockingDeque is. It is implemented by Collection interface and the AbstractQueue class. It provides optional boundaries based on linked nodes. It going to pass memory size to a constructor and helps to provide memory wastage in android.This example demonstrates about How to use peekFirst() in android LinkedBlockingDequeStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, we have taken a ... Read More

Use peekFirst in Android ConcurrentLinkedDeque

Samual Sam
Updated on 30-Jun-2020 14:57:54

117 Views

Before getting into the example, we should know what ConcurrentLinkedDeque is, it is unbounded deque based on linked nodes. Multiple threads can access deque elements with safety.This example demonstrates about How to use peekFirst() in android ConcurrentLinkedDequeStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, we have taken a text view to show ConcurrentLinkedDeque elements.Step 3 − Add the following code to src/MainActivity.javapackage com.example.myapplication; import android.os.Build; import android.os.Bundle; ... Read More

Use Peek in Android ConcurrentLinkedQueue

karthikeya Boyini
Updated on 30-Jun-2020 14:57:28

148 Views

Before getting into an example, we should know what ConcurrentLinkedQueue is, it is an unbounded queue based on linked nodes. Multiple threads can access queue elements with safety. Elements travel based on queue strategy as FIFO and elements going to insert from a tail. It does not allow null values.This example demonstrates about How to use peek() in android ConcurrentLinkedQueueStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, ... Read More

Find a Specific Column in All Tables in a Database

karthikeya Boyini
Updated on 30-Jun-2020 14:56:44

718 Views

For this, use COLUMN_NAME and set LIKE with that specific column name. Let us find a specific column in an unknown table in a database −mysql> SELECT TABLE_NAME, COLUMN_NAME, DATA_TYPE, IS_NULLABLE, COLUMN_DEFAULT    -> FROM INFORMATION_SCHEMA.COLUMNS    -> WHERE column_name LIKE '%StudentName%'    -> AND table_schema = 'web';OutputThis will produce the following output −+-------------------+-------------+-----------+-------------+----------------+ | TABLE_NAME        | COLUMN_NAME | DATA_TYPE | IS_NULLABLE |COLUMN_DEFAULT  | +-------------------+-------------+-----------+-------------+----------------+ | demotable215      | StudentName | varchar   | YES         | NULL           | | demotable221      | StudentName | varchar   ... Read More

Use Peek in Android PriorityBlockingQueue

Samual Sam
Updated on 30-Jun-2020 14:55:17

127 Views

Before getting into the example, we should know what PriorityBlockingQueue is. It is an unbounded queue and follows the same order as a priority queue. The main usage of priority blocking queue is, it going to handle out of memory error.This example demonstrates about How to use peek() in android PriorityBlockingQueueStep 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.     In the above code, we have taken a text view to show PriorityBlockingQueue ... Read More

MySQL Query to Select Top 10 Records

Sharon Christine
Updated on 30-Jun-2020 14:54:57

11K+ Views

To select top 10 records, use LIMIT in MySQL. Let us first create a table −mysql> create table DemoTable -> ( -> PageNumber text -> ); Query OK, 0 rows affected (2.50 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Page-1'); Query OK, 1 row affected (0.46 sec) mysql> insert into DemoTable values('Page-2'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('Page-3'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values('Page-4'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Page-5'); Query OK, ... Read More

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