To answer this question, you need to understand SQL statements for inserting new data into a database.

Let's go through each option to understand why it is correct or incorrect:

Option A) INSERT NEW - This option is incorrect because there is no SQL statement called "INSERT NEW" for inserting new data into a database.

Option B) ADD NEW - This option is incorrect because there is no SQL statement called "ADD NEW" for inserting new data into a database.

Option C) ADD RECORD - This option is incorrect because there is no SQL statement called "ADD RECORD" for inserting new data into a database.

Option D) INSERT INTO - This option is correct because the SQL statement "INSERT INTO" is used to insert new data into a database.

The correct answer is D) INSERT INTO. This option is correct because the "INSERT INTO" statement is commonly used in SQL to add new records to a database table.

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To select a column named 'FirstName' from a table named 'Persons' in SQL, you would use the SELECT statement. Let's go through each option to understand why it is correct or incorrect:

Option A) SELECT FirstName FROM Persons - This option is correct because it uses the SELECT statement to specify the column 'FirstName' that you want to retrieve from the table 'Persons'.

Option B) EXTRACT FirstName FROM Persons - This option is incorrect. The EXTRACT keyword is used to extract parts of a date or time value, not for selecting columns from a table.

Option C) SELECT Persons.FirstName - This option is incorrect. Although it specifies the desired column 'FirstName', it is missing the keyword FROM, which is necessary to indicate the table 'Persons' from which to retrieve the column.

Option D) SELECT * FROM Persons - This option is incorrect. The asterisk (*) symbol is used to select all columns from a table. It does not specifically select only the 'FirstName' column.

The correct answer is A) SELECT FirstName FROM Persons. This option is correct because it uses the SELECT statement to specify the 'FirstName' column from the 'Persons' table.

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To answer this question, you need to understand how to use the LIKE operator in SQL. The LIKE operator is used to search for a specified pattern in a column.

Let's go through each option to understand why it is correct or incorrect:

Option A) SELECT * FROM Persons WHERE FirstName LIKE 'a%' - This option is correct. The LIKE 'a%' condition will select all records from the 'Persons' table where the value of the 'FirstName' column starts with an 'a'.

Option B) SELECT * FROM Persons WHERE FirstName LIKE '%a' - This option is incorrect. The LIKE '%a' condition will select all records from the 'Persons' table where the value of the 'FirstName' column ends with an 'a', not starts with an 'a'.

Option C) SELECT * FROM Persons WHERE FirstName='a' - This option is incorrect. The = operator is used for exact matches. The condition FirstName='a' will select only the records where the value of the 'FirstName' column is exactly 'a', not those that start with an 'a'.

Option D) SELECT * FROM Persons WHERE FirstName='%a%' - This option is incorrect. The % wildcard character is used to match any sequence of characters. The condition FirstName='%a%' will select all records where the value of the 'FirstName' column contains an 'a' anywhere, not just at the beginning.

The correct answer is Option A) SELECT * FROM Persons WHERE FirstName LIKE 'a%'. This option is correct because it selects all records from the 'Persons' table where the value of the 'FirstName' column starts with an 'a'.

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To answer this question, you need to understand the SUBSTRING function in SQL.

The SUBSTRING function is used to extract a substring from a given string. It takes three arguments: the input string, the starting position, and the length of the substring to be extracted.

In this case, the input string is '123456'. The starting position is 0, and the length is 3.

Using these arguments, the SUBSTRING function will extract a substring starting from the 0th position (which is the first character) with a length of 3 characters.

So, the output of the SUBSTRING('123456', 0, 3) statement will be '12'.

Therefore, the correct answer is B) 12.

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To answer this question, you need to understand the differences between the commands DROP, DELETE, and TRUNCATE in the context of deleting data from a table.

Option A) DROP - This option is incorrect because the DROP command is used to delete an entire table or database object, including its structure. It does not specifically delete data from a table without affecting the rollback segment.

Option B) DELETE - This option is incorrect because the DELETE command is used to delete specific rows from a table based on a condition. It does write to the rollback segment to allow for a rollback operation if needed.

Option C) TRUNCATE - This option is correct because the TRUNCATE command is used to delete all data from a table, but it does not write to the rollback segment. TRUNCATE is a DDL (Data Definition Language) command that is faster than DELETE because it deallocates the data pages and resets the highwater mark, freeing the space for reuse.

Option D) REMOVE - This option is incorrect because the REMOVE command is not a valid command in most database systems.

Option E) NONE OF THE ABOVE - This option is incorrect because option C (TRUNCATE) is the correct answer.

The correct answer is C) TRUNCATE. This option is correct because it deletes all data from a table without writing to the rollback segment.

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