Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
MERGE and TRUNCATE in SQL
SQL has two more table update operators, MERGE and TRUNCATE. MERGE, like INSERT, takes a source table s and uses it to update a target table t. Briefly, a MERGE statement specifies a matching condition to determine which rows of s have at least one matching row in t (under that specified matching condition). It then specifies an open-ended series of conditions to be applied to each row of s paired with actions to be applied on t.
WHEN MATCHED AND c1 THEN x1 specifies that action x1, necessarily an UPDATE or DELETE, is to be applied on t for each matching row in s that satisfies the condition c1. WHEN NOT MATCHED AND c2 THEN x2 specifies that action x2, necessarily an INSERT, is to be applied on t for each non-matching row in s that satisfies the condition c2. The curiously named TRUNCATE statement deletes all the rows from its specified target, bypassing any triggered actions, including compensatory actions, specified for that target. The target must be a base table.
Problem: (a) Define the following terms: (i) data mining. (ii) OLAP. (b) Differentiate between snowflake schema and star schema. Support your answer with appropriate
Create a Oracle procedure to produce vertical output format when selecting rows from a database table.
Name Resolution During the compilation, the PL/SQL compiler relates identifiers like the name of a variable with an address or memory location, actual value, or datatype. Th
OPEN-FOR Statement The OPEN-FOR statements execute the multi-row query related with a cursor variable. It also allocates the resources used by the Oracle to process the query a
Bulk Fetching The illustration below shows that you can bulk-fetch from a cursor into one or more collections: DECLARE TYPE NameTab IS TABLE OF emp.ename%TYPE; TYPE S
How Exceptions Propagate ? Whenever an exception is raised, and if the PL/SQL cannot find a handler for it in the present subprogram or block, the exception propagates. That is
How do I display usernames for students from a student table, assigning each student a username initials001 (initials is the actual student initials), and if the students initials
Using a join on 3 tables, select 5 columns and 10 rows from the 3 tables without the use of a Cartesian product Query: SELECT E.LAST_NAME, E.FIRST_NAME, S.BUILDING, S.BRAN
Data Types in SQL - XML, Array, Row BINARY LARGE OBJECT for arbitrarily large bit strings. XML for XML documents and fragments. ARRAY types for arrays.
This is a Customer Management project. Customer data is presented in a text file. The program will load this text data into its DB columns. The data mapping is user definable. User
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd