Your Shortcut to Smarter Tech.
Candidate key is the set of attributes by which it is possible to identify each row of the table. Therefore, if some attribute is nullable, it cannot be one of candidate keys. Can a candidate key have a null value? Any attribute of Primary key can not contain NULL value. While in Candidate key any attribute can contain NULL value. …
Semantic SQL is simple to create SQL queries with no Joins or Union statements. The semantic SQL queries are formulated in standard SQL and query the semantic business model (ontology) mapped to the data, instead of querying the data directly. It is also used to query Views created with the semantic model. What are semantics in SQL? The semantics of …
Generally errors are classified into three types: systematic errors, random errors and blunders. What are the types of errors Class 11? 1) Instrumental error: This error occurs due to poor calibration of the measuring device or the measuring apparatus. 2) Observational error: This error occurs due to poor observation by the observer, while taking measurements. Observational error is also called …
Side note: UDP port 1443 uses the Datagram Protocol, a communications protocol for the Internet network layer, transport layer, and session layer. This protocol when used over PORT 1443 makes possible the transmission of a datagram message from one computer to an application running in another computer. Is port 1443 a TCP or UDP? Side note: TCP port 1443 uses …
Launch the MySQL Command-Line Client. To launch the client, enter the following command in a Command Prompt window: mysql -u root -p . The -p option is needed only if a root password is defined for MySQL. Enter the password when prompted. How do I connect to a MySQL database? To Connect to a MySQL Database Expand the Drivers node …
Type 1 dimension mapping (SCD1): This keeps only current data and does not maintain historical data. Note : Use SCD1 mapping when you do not want history of previous data. Type 2 dimension/version number mapping (SCD2): This keeps current as well as historical data in the table. What is SCD type1? Type 1 SCDs – Overwriting. In a Type 1 …
To broaden the selections of a structured query language (SQL-SELECT) statement, two wildcard characters, the percent sign (%) and the underscore (_), can be used. What are the two types of wildcards? The most common wildcards are the asterisk (*), which represents one or more characters, and question mark (?), which represents a single character. How many wildcards are there …
If you have cPanel or Plesk access you should be able to open PHPMyAdmin when logged in to the hosting account. In PHPMyAdmin on the right side, it should have information listen under the “Database server” section and the “Server version” is what shows the MySQL or MariaDB version is running on the server. How do I find MariaDB version …
Although much less susceptible than Plasma TVs, LCD TVs are still subject to screen burn in (image retention). In general, you should avoid keeping a static picture (that is, a picture that contains no or few moving elements) or a picture with static elements (black bars, black borders, logos, etc.) How do you know if your LCD is burnt out? …
“And similar to your computer, the electrical components don’t last forever. Together, these factors all contribute to the lifespan of an LED display. Looking at just the diode lifespan doesn’t give you the complete story — almost always, another part will go out first.” How long do LED displays last? The average lifespan of an LED at maximum or close-to-maximum …