question Which command is used to select all columns from a table named employees

Database

Which command is used to select all columns from a table named "employees"?

A. SELECT * FROM employees;
B. SELECT ALL FROM employees;
C. SHOW COLUMNS FROM employees;
D. DISPLAY employees;

'SELECT * FROM employees;' selects all columns from the "employees" table.

Which SQL function is used to find the highest value in a column?

A. MAX()
B. HIGH()
C. TOP()
D. HIGHEST()

Which SQL Server data type is used to store a date and time combination?

A. DATETIME
B. DATE
C. TIMESTAMP
D. TIME

What is the purpose of the Oracle SYS_CONTEXT function?

A. Concatenate multiple values
B. Find the length of a string
C. Retrieve the value of a parameter in the database context
D. Validate XML structure

Which Oracle function is used to find the current user?

A. GETUSER()
B. CURRENT_USER()
C. USER()
D. SESSION_USER()

Which SQL statement is used to change the value of an existing record in a table?

A. MODIFY
B. CHANGE
C. UPDATE
D. SET

Which MySQL command is used to retrieve the definition of a table?

A. DESCRIBE
B. SHOW TABLE
C. DISPLAY TABLE
D. INFO TABLE

What is the purpose of the SQL LIKE operator?

A. Filter rows based on a condition
B. Sort the result set
C. Combine rows into groups
D. Search for a specified pattern in a column

Which SQL statement is used to grant specific privileges to a user in MySQL?

A. ALLOW PRIVILEGES
B. GRANT PRIVILEGES
C. GRANT
D. ALLOW ACCESS

In MySQL, which type of index allows only unique values and nulls are considered distinct?

A. PRIMARY KEY
B. UNIQUE
C. FULLTEXT
D. INDEX

Which statement is used to delete records from a table in SQL Server?

A. DELETE FROM table;
B. REMOVE * FROM table;
C. TRUNCATE TABLE table;
D. DROP TABLE table;