Articles on Trending Technologies

Technical articles with clear explanations and examples

Address/data buffers in 8085 Microprocessor

Chandu yadav
Chandu yadav
Updated on 30-Jul-2019 3K+ Views

Address and data buffers are used for bidirectional data transfer. They perform the unidirectional data transfer when they send out the Least Significant Byte of the address. These buffers are only used for increasing the driving capacity of the current. Through the internal bus data goes to the buffers. The Least Significant Byte of the address goes to the buffers from the internal address latch to the other.Hence the address or data are sent out on the address ranging from AD7 to AD0 can drive every external chips, like chips of RAM, chips of EPROM, and other peripheral chips meant for ...

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How to select only non - numeric values from varchar column in MySQL?

Chandu yadav
Chandu yadav
Updated on 30-Jul-2019 1K+ Views

You need to use REGEXP for this. The syntax is as followsSELECT *FROM yourTableName WHERE yourColumnName REGEXP '[a-zA-Z]';To understand the concept, let us create a table. The query to create a table is as followsmysql> create table SelectNonNumericValue    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> UserId varchar(100)    -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table using insert command. The query is as followsmysql> insert into SelectNonNumericValue(UserId) values('123John'); Query OK, 1 row affected (0.12 sec) mysql> insert into SelectNonNumericValue(UserId) values('58475Carol98457Taylor24'); Query OK, 1 row affected (0.52 sec) ...

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Display sum in last row of table using MySQL?

George John
George John
Updated on 30-Jul-2019 1K+ Views

To display sum in last row of a table, you can use UNION. To understand how, let us create a tablemysql> create table showSumInLastRowDemo    -> (    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> StudentName varchar(20),    -> StudentMarks int    -> ); Query OK, 0 rows affected (0.69 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into showSumInLastRowDemo(StudentName, StudentMarks) values('John', 56); Query OK, 1 row affected (0.14 sec) mysql> insert into showSumInLastRowDemo(StudentName, StudentMarks) values('John', 87); Query OK, 1 row affected (0.10 sec) mysql> insert into showSumInLastRowDemo(StudentName, StudentMarks) ...

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C++ Program to Perform Operations in a BST

Daniol Thomas
Daniol Thomas
Updated on 30-Jul-2019 3K+ Views

         A Binary Search Tree is a sorted binary tree in which all the nodes will have following properties−The right sub-tree of a node has a key greater than to its parent node's key.The left sub-tree of a node has a key lesser than to its parent node's key.All key values are distinct.Each node cannot have more than two children.Class Descriptions:Begin    class BST to declare following functions:       search() = To search an item in BST.       initialize temp = root;       while(temp != NULL)          Increase ...

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Create a column on my table that allows null but is set by default to empty (not null)?

Samual Sam
Samual Sam
Updated on 30-Jul-2019 751 Views

You need to use default keyword for this. The syntax is as follows −alter table yourTableName add yourColumnName yourDataType NULL Default '';To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table AllowNullDefaulNotNullDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> UserName varchar(20),    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.65 sec)Let us add a new column that allow NULL value but default value set to NOT NULL. The query is as follows −mysql> alter table AllowNullDefaulNotNullDemo add UserAddress varchar(20) ...

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Internal address latch in 8085 Microprocessor

George John
George John
Updated on 30-Jul-2019 566 Views

The select unit of the register in the 8085 selects any one of the register pairs (BC, DE, HL, SP, PC, or WZ) for sending them to it to the latch unit specified for addressing. For example, the contents of the PC be C200H. If the selection unit be the register which selects the PC, and sends C200H from the PC to the address latch internally thereafter the latch holds the specified value and sends directly out to the pins of the address after buffering. The Most Significant Byte of the address i.e. the C2H, is sent out to the ...

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Count multiple occurrences of separate texts in MySQL?

George John
George John
Updated on 30-Jul-2019 401 Views

You can use aggregate function count along with if() for this. To understand the concept, let us create a table. The query to create a table is as followsmysql> create table CountOccurrencesDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> TechnicalSubject varchar(100)    -> ); Query OK, 0 rows affected (0.68 sec)Now you can insert some records in the table using insert command. The query is as followsmysql> insert into CountOccurrencesDemo(TechnicalSubject) values('Java'); Query OK, 1 row affected (0.14 sec) mysql> insert into CountOccurrencesDemo(TechnicalSubject) values('MongoDB'); Query OK, 1 row affected (0.13 sec) mysql> insert into ...

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Order by a function of two columns in a single MySQL query

Ankith Reddy
Ankith Reddy
Updated on 30-Jul-2019 189 Views

Let us first create a tablemysql> create table orderByAFunctionDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> FirstNumber int,    -> SecodNumber int    -> ); Query OK, 0 rows affected (0.44 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(10, 4); Query OK, 1 row affected (0.11 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(45, 78); Query OK, 1 row affected (0.17 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(23, 10); Query OK, 1 row affected (0.12 sec) mysql> insert into orderByAFunctionDemo(FirstNumber, SecodNumber) values(67, ...

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C++ Program to Implement Network_Flow Problem

Daniol Thomas
Daniol Thomas
Updated on 30-Jul-2019 700 Views

This is a C++ Program to implement Network_Flow problem using Ford Fulkerson algorithm.Algorithms:Begin    function bfs() returns true if there is path from source s to sink t in    the residual graph which indicates additional possible flow in the graph. End Begin    function fordfulkarson() return maximum flow in given graph:    A) initiate flow as 0.    B) If there is an augmenting path from source to sink, add the path to flow.    C) Return flow. EndExample Code#include #include #include #include #define n 7 using namespace std; bool bfs(int g[n][n], int s, int ...

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Iterate through Quartet class in JavaTuples

Samual Sam
Samual Sam
Updated on 30-Jul-2019 198 Views

You can also iterate through Quartet class like Arrays using a loop.Let us first see what we need to work with JavaTuples. To work with Quartet class in JavaTuples, you need to import the following package −import org.javatuples.Quartet;Note − Steps to download and run JavaTuples program. If you are using Eclipse IDE to run Quartet Class in JavaTuples, then Right Click Project → Properties → Java Build Path → Add External Jars and upload the downloaded JavaTuples jar file.The following is an example −Exampleimport org.javatuples.Quartet; public class Demo { public static void main(String[] args) { ...

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