Chandu yadav has Published 1091 Articles

Why does MySQL refuse pipe ('|') character in string on INSERT INTO?

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

298 Views

To insert pipe(|) character in string on INSERT INTO, let us first see an example and create a table. The query to create a table is as followsmysql> create table PipeInsertDemo -> ( -> UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ... Read More

How to select first and last row record using LIMIT in MySQL?

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

2K+ Views

Let us first create a table. The query to create a table is as followsmysql> create table FirstAndLastDataDemo    -> (    -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> EmployeeName varchar(20),    -> EmployeeAge int    -> ); Query OK, 0 rows affected (0.59 sec)Insert some records ... Read More

Program counter (PC) in 8085 Microprocessor

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

8K+ Views

PC is a 16-bit register. It contains a memory address. PC contains that very memory address from where the next instruction is to be fetched for execution. Suppose the PC contents are 8000H, then it means that the 8085 Desires to fetch the instruction Byte at 8000H. After fetching the ... Read More

How can I enforce compound uniqueness in MySQL?

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

77 Views

You can enforce compound uniqueness in MySQL with the help of UNIQUE keyword. Here is the syntax to add UNIQUE keyword to your table column.The syntax is as followsCREATE TABLE yourTableName (    yourColumnName1 datatype,    yourColumnName2 datatype,    yourColumnName3 datatype,    .    .    N    UNIQUE yourConstarintName(yourColumnName2, ... Read More

How to use MongoDB $pull to delete documents within an Array?

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

251 Views

You need to use update command along with $pull operator to delete documents within an array. Let us create a collection with documents. Following is the query> db.deleteDocumentsDemo.insertOne( ... { ...    "_id":100, ...    "StudentsDetails" : [ ...       { ...          "StudentId" : ... Read More

Timing and control unit in 8085 Microprocessor

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

14K+ Views

We use Timing and Controlling unit in 8085 for the generation of timing signals and the signals to control. All the operations and functions both interior and exterior of a microprocessor are controlled by this unit. X2 and CLK output pins: To do or rather perform the operations of timing ... Read More

The indexOf() method of AbstractList class in Java

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

138 Views

The indexOf() method is used to return the index of the first occurrence of the specified element in this list. If the list is empty, it returns -1.The syntax is as follows.int indexOf(Object ob)Here, the parameter ob is the element to search for.To work with the AbstractList class, import the ... Read More

How to compare two strings which are numbers in MySQL?

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

1K+ Views

To compare two strings which are numbers in MySQL, use the CAST() function.The syntax is as followsselect *from yourTableName where cast(yourColumnName as signed)=yourIntegerValue;To understand the above syntax, let us create a table. The query to create a table is as followsmysql> create table compareTwoStringDemo -> ( ... Read More

How to reduce MongoDB storage space after deleting large amount of data?

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

483 Views

To reduce MongoDB storage space after deleting a large amount of data, you need to use repairDatabase(). Let’s say we are using the database “test”. Following is the query to get to the current database> db;This will produce the following outputTestAfter deleting large amount of data, this is how you ... Read More

Address/data buffers in 8085 Microprocessor

Chandu yadav

Chandu yadav

Updated on 30-Jul-2019 22:30:25

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 ... Read More

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