COMPUTER SCIENCE AND ENGINEERING
SQL
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
Which SQL function is used to count the number of rows in a SQL query?
|
|
COUNT()
|
|
|
NUMBER()
|
|
|
SUM()
|
|
|
COUNT(*)
|
Explanation:
Detailed explanation-1: -SQL COUNT() function counts the total number of rows present in the database.
Detailed explanation-2: -COUNT(*) with GROUP BY returns the number of rows in each group. This includes NULL values and duplicates. COUNT(ALL <expression>) evaluates expression for each row in a group, and returns the number of nonnull values.
Detailed explanation-3: -The COUNT (*) function returns the number of rows that satisfy the WHERE clause of a SELECT statement. The following example finds how many rows in the stock table have the value HRO in the manu code column: SELECT COUNT(*) FROM stock WHERE manu code = ‘HRO’;
Detailed explanation-4: -The COUNT() function returns the number of rows in a database table.
There is 1 question to complete.