Question: How Many Rows Will Be Deleted From The Employees Table With The Following Statement Delete From Employees Where Last_name King ‘;?

What would be the result of the following statement delete from employees?


What would be the result of the following statement: DELETE employees; Nothing, no data will be changed.

The statement will fail because it contains a syntax error..

Which methods are used commit a series of database changes?

Python’s commit() method and rollback() method are among the various methods used for making database transactions. Database transactions are necessary as they ensure the atomacity, constitency, isolation and durability of the database.

Can we use where clause in update statement?

UPDATE Syntax Notice the WHERE clause in the UPDATE statement. The WHERE clause specifies which record(s) that should be updated. If you omit the WHERE clause, all records in the table will be updated!

Can trigger change the table from which it has been called?

A trigger cannot change the table from which it has been called. If there is a trigger called as a result of insert on a table, then the trigger cannot insert/update the same table.

When the where clause is missing in a delete statement what is the result?

The result of the DELETE statement is the removal of zero or more rows of a table, depending on how many rows satisfy the search condition specified in the WHERE clause. If you omit the WHERE clause from a DELETE statement, SQL removes all the rows from the table.

Can you insert more than one row at a time using an insert statement with a value clause?

The VALUES clause in an INSERT statement is mandatory in a subquery. No rows, as the SELECT statement is invalid. 10 rows will be created. No rows, as you cannot use subqueries in an insert statement.

Which SQL statement is used to remove all the changes made by an uncommitted transaction?

Rollback of Transactions Rolling back means undoing any changes to data that have been performed by SQL statements within an uncommitted transaction. Oracle uses undo tablespaces (or rollback segments) to store old values. The redo log contains a record of changes.

How can I insert 100 rows in SQL?

You could use the table master. dbo. spt_values : set identity_insert #test1 off; insert into #test1 (test_id) select top (100) row_number() over (order by (select null)) from master.

How do I display multiple rows in one record in SQL?

Here is the example.Create a database.Create 2 tables as in the following.Execute this SQL Query to get the student courseIds separated by a comma. USE StudentCourseDB. SELECT StudentID, CourseIDs=STUFF. ( ( SELECT DISTINCT ‘, ‘ + CAST(CourseID AS VARCHAR(MAX)) FROM StudentCourses t2. WHERE t2.StudentID = t1.StudentID.

What happens if a transaction is not committed?

As long as you don’t COMMIT or ROLLBACK a transaction, it’s still “running” and potentially holding locks. If your client (application or user) closes the connection to the database before committing, any still running transactions will be rolled back and terminated.

Is the following statement valid ie is it allowed to update rows in one table?

Is the following statement valid, i.e. is it allowed to update rows in one table, based on a subquery from another table? … The statement will fail because the subqueries are returning data from different rows. No, this does nothing.

What is difference between drop and delete command?

DELETE is a Data Manipulation Language command, DML command and is used to remove tuples/records from a relation/table. Whereas DROP is a Data Definition Language, DDL command and is used to remove named elements of schema like relations/table, constraints or entire schema.

What is the function of a full outer join?

The FULL OUTER JOIN keyword returns all records when there is a match in left (table1) or right (table2) table records. Note: FULL OUTER JOIN can potentially return very large result-sets! Tip: FULL OUTER JOIN and FULL JOIN are the same.

What would happen if you issued a delete statement without a where clause?

If you will not provide where clause with delete statement, then whole table data will be deleted. … In the syntax above the deletion happens without any condition and will delete all the records of the table.

How can I insert more than 1000 rows in SQL?

The number of rows that you can insert at a time is 1,000 rows using this form of the INSERT statement. If you want to insert more rows than that, you should consider using multiple INSERT statements, BULK INSERT or a derived table.

Why do we need transactions in database?

The primary benefit of using transactions is data integrity. Many database uses require storing data to multiple tables, or multiple rows to the same table in order to maintain a consistent data set. Using transactions ensures that other connections to the same database see either all the updates or none of them.

Can we use and in update query?

SQL update multiple columns with boolean ‘AND’ In the following, we are going to discuss how to change the data of one or more columns with the SQL UPDATE statement along with one or more condition which can be joined by BOOLEAN AND operator.

Which command could you use to quickly remove all data from the rows in a table without deleting the table itself?

TRUNCATE. TRUNCATE is a statement that will essentially remove all records from the table, just as if you had used DELETE without a WHERE clause. This means TRUNCATE will remove all records in your table, but its structure will remain intact.