Jammy 
Avoid using SELECT * When writing queries, it would be better to set the columns you need in the select statement rather than SELECT *. There are many reasons for that recommendation, like: SELECT * Retrieves unnecessary data besides that it may increase the network traffic used for your queries. Why should you not use SELECT * in SQL? By …
Subtracts the value of the right operand from the value of the left operand and assigns the result to the left operand. C -= A is same as C = C – A. *= Multiply then assign. Multiplies the value of the right operand with the value of the left operand and assigns the result to the left operand. What …
The wildcard selector literally means any descendant of the preceding selector. So given a selector like div#nav * would match any elements that are nested with a element, but not the element itself. Let me show you a useful example. What is the purpose of * In selector? Answer: A selector is one of the properties of the object that …
COUNT(*) returns the number of rows in a specified table, and it preserves duplicate rows. It counts each row separately. This includes rows that contain null values. What is the use of count (*)? What is the use of * in SQL? The second part of a SQL query is the name of the column you want to retrieve for …
An asterisk is a star-shaped symbol (*) that has a few uses in writing. It is most commonly used to signal a footnote, but it is sometimes also used to clarify a statement or to censor inappropriate language. What does an asterisk (*) mean in your code? (2) In programming, the asterisk or “star” symbol (*) means multiplication. For example, …
An asterisk (” * “) can be used to specify that the query should return all columns of the queried tables. SELECT is the most complex statement in SQL, with optional keywords and clauses that include: The FROM clause, which indicates the table(s) to retrieve data from. What does * represent in SQL? A wildcard character is used to substitute …
LIKE is an operator similar to LIKE in SQL. We use LIKE to search for string with similar text. RLIKE (Right-Like) is a special function in Hive where if any substring of A matches with B then it evaluates to true. It also obeys Java regular expression pattern. What is Rlike in SQL? The RLIKE operator in MySQL is used …
The SQL Like is used when we want to return the row if specific character string matches a specified pattern. The pattern can be a combination of regular characters and wildcard characters. To return a row back, regular characters must exactly match the characters specified in the character string. When should I use like in SQL? The SQL Like is …
