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We can convert MySQL date and time to Unix Timestamp with the help of function UNIX_TIMESTAMP(). The following is the query. mysql> SELECT UNIX_TIMESTAMP(STR_TO_DATE('Oct 19 2018 10:00PM', '%M %d %Y %h:%i%p')); After running the above query we will not get the output in date format as shown in the below output. The output shown here is a Unix Timestamp. +------------------------------------------------------------------------+ | UNIX_TIMESTAMP(STR_TO_DATE('Oct 19 2018 10:00PM', '%M %d %Y %h:%i%p')) | +------------------------------------------------------------------------+ | ... Read More
The int type takes 4 byte signed integer i.e. 32 bits ( 232 values can be stored). The BigInt type takes 8 byte signed integer i.e. 64 bits (264 values can be stored). Let us see an example. Creating a table with zerofill, that would add leading zeros. mysql> create table IntandBigint20Demo -> ( -> Number int(20) zerofill, -> Code BigInt(20) zerofill -> ); Query OK, 0 rows affected (0.58 sec) After creating a table, we will insert records into the table. mysql> insert into ... Read More
Key is synonymous to an index. If you want to create an index for a column, then use ‘Key’. As stated in the official docs: KEY is normally a synonym for INDEX. The key attribute PRIMARY KEY can also be specified as just KEY when given in a column definition. This was implemented for compatibility with other database systems. The key can be used with Primary Key: Let us first create a table. Here is the query to set primary key for a column “id”. mysql> create table KeyDemo -> ( ... Read More
Interfaces define properties, methods, and events, which are the members of the interface. Interfaces contain only the declaration of the members. It is the responsibility of the deriving class to define the members. Abstract classes to some extent serve the same purpose, however, they are mostly used when only few methods are to be declared by the base class and the deriving class implements the functionalities. Let us now see the difference between Abstract class and Interface in C#. Inherit A class may inherit more than one interface, whereas a class may inherit only one abstract class. Member Field You ... Read More
Cable modem termination system (CMTS) is a hardware device at the headend of a cable TV network that is used to connect cable subscribers to the Internet Service Provider (ISP). They provide high speed data services like Internet or Voice over Internet Protocol (VoIP) over the cable TV network. Functions CMTS has both radio frequency interfaces and Ethernet interfaces. It transmits and receives user data packets to and from the cable modem attached to the subscriber through HFC network. It then converts them to Internet Protocol packets (IP packets) and routes them to the concerned Internet Service ... Read More
InnoDB is a general-purpose storage engine that balances high reliability and performance. Since MySQL 5.6, InnoDB is the default MySQL storage engine. InnoDB can be used for various purposes. Here are some of them − It can be used for transaction purpose i.e. all ACID properties. InnoDB can be used for row level locking, that means it gives higher performance as compared to MyISAM. InnoDB can be used for both data and index for a large buffer pool. InnoDB can be used when we need better performance than MyISAM. MyISAM is the default storage engine for the MySQL ... Read More
We can return 0 for NULL in MySQL with the help of IFNULL() method. The syntax of IFNULL() is as follows. IFNULL(YOUREXPRESSION, 0); Let us see an example. First, we will create a table. mysql> create table NullDemoWithZero -> ( -> id varchar(200) -> ); Query OK, 0 rows affected (0.65 sec) After creating a table, let us insert some records in the table using the INSERT command. The query is as follows − mysql> insert into NullDemoWithZero values(); Query OK, 1 row affected (0.16 sec) ... Read More
Boxing convert value type to an object type whereas unboxing converts object type to the value type. Let us see the difference between Boxing and Unboxing in C#. Storage In boxing, the value stored on the stack is copied to the object stored on heap memory, whereas unboxing is the opposite. In Unboxing, the object's value stored on the heap memory is copied to the value type stored on stack. Conversion Unboxing has explicit conversion whereas boxing has implicit conversion. Example int a = 10; object obj = a; // boxing int b = (int) ob; // unboxing
We can escape apostrophe (‘) in MySQL in the following two ways − We can use backslash. We can use single quotes twice (double quoted) Using backslash Let us first create a table. mysql> create table SingleQuotesDemo - > ( - > id int, - > name varchar(100) - > ); Query OK, 0 rows affected (1.16 sec) Following direct usage does not give the desired result for name “John’s”. mysql> insert into SingleQuotesDemo values(1, 'John's'); '> Let us now use backslash. ... Read More
To get the list of MySQL user accounts, we can use “SELECT USER”. The following is the query to display the list. SELECT User FROM mysql.user; Here is the output. +------------------+ | User | +------------------+ | John | | Mac | | Manish | | mysql.infoschema | | mysql.session ... Read More