May 13
Raise Error in Oracle
RAISE VALUE_ERROR;
Raise Application Error in Oracle
Create custom exception and raise it.
Handle Exception
You could also insert into error log table and RAISE
Reference:
https://blogs.oracle.com/connect/post/error-management
May 12
"Collaboration diagrams (known as Communication Diagram in UML 2.x) are used to show how objects interact to perform the behavior of a particular use case, or a part of a use case. Along with sequence diagrams, collaboration are used by designers to define and clarify the roles of the objects that perform a particular flow of events of a use case. They are the primary source of information used to determining class responsibilities and interfaces."
Ref: Check Below
May 12
How it works: if, elsif, else (then) (Click on the images to see them clearly)
Ref: https://docs.oracle.com/cd/B13789_01/appdev.101/b10807/13_elems024.htm
Example:
Ref: https://docs.oracle.com/cd/B13789_01/appdev.101/b10807/13_elems024.htm
Oracle: CASE, WHEN, THEN
Simple:
Searched:
”
Else:
Reverse For Loop
Ref: For Loop Examples in Oracle
https://docs.oracle.com/cd/E11882_01/appdev.112/e25519/controlstatements.htm#BABEFFDC
Oracle While Loop
While loop example from the referenced url
DECLARE
done BOOLEAN := FALSE;
BEGIN
WHILE done LOOP
DBMS_OUTPUT.PUT_LINE (‘This line does not print.’);
done := TRUE; — This assignment is not made.
END LOOP;
WHILE NOT done LOOP
DBMS_OUTPUT.PUT_LINE (‘Hello, world!’);
done := TRUE;
END LOOP;
END;
/
May 12
An unconstrained subtype has the same set of values as its base type, so it is only another name for the base type.
Syntax:
SUBTYPE subtype_name IS base_type
Example:
SUBTYPE "DOUBLE PRECISION" IS FLOAT
SUBTYPE Balance IS NUMBER;
Constrained SubType
SUBTYPE Balance IS NUMBER(8,2);
Oracle Exception Block Example:
Ref: https://docs.oracle.com/cd/B13789_01/appdev.101/b10807/07_errs.htm
May 12
Ref: https://docs.oracle.com/cd/B13789_01/appdev.101/b10807/02_funds.htm
https://stackoverflow.com/questions/7425153/reason-why-oracle-is-case-sensitive
Oracle Data Types and Allowed Sizes:
https://docs.oracle.com/cd/E11882_01/appdev.112/e25519/datatypes.htm#LNPLS99943
Oracle SIMPLE_FLOAT vs SIMPLE_DOUBLE
Ref: https://docs.oracle.com/cd/B28359_01/appdev.111/b28370/datatypes.htm#CJAEAEJG
PLS_Integer vs Number
"The PLS_INTEGER data type has these advantages over the NUMBER data type and NUMBER subtypes:
PLS_INTEGER values require less storage.PLS_INTEGER operations use hardware arithmetic, so they are faster than NUMBER operations,"
Ref: https://docs.oracle.com/cd/E11882_01/appdev.112/e25519/datatypes.htm#LNPLS319
Hardly anything is by me. All are from external sources. Credit belongs to them.
May 12
Data Types
Ref: https://docs.oracle.com/cd/A97630_01/server.920/a96524/c13datyp.htm
(Click on the image to see it properly)
Why PLS_Integer:
https://docs.oracle.com/cd/B13789_01/appdev.101/b10807/03_types.htm
“You use the PLS_INTEGER datatype to store signed integers. Its magnitude range is -231 .. 231. PLS_INTEGER values require less storage than NUMBER values. Also, PLS_INTEGER operations use machine arithmetic, so they are faster than NUMBER and BINARY_INTEGER operations, which use library arithmetic. For efficiency, use PLS_INTEGER for all calculations that fall within its magnitude range.”
ROWID vs ROWNUM
ROWID is useful when you need to refer to a specific row in a table without using a primary key or unique constraint. Hence, ROWNUM is a pseudocolumn that assigns a unique row number to each row in a result set, while ROWID is a physical address that identifies a specific row in a table
https://www.c-sharpcorner.com/interview-question/what-is-the-difference-between-rownum-and-rowed
Simple Integer vs PLS_integer
https://docs.oracle.com/en/database/oracle/oracle-database/19/lnpls/plsql-data-types.html
“SIMPLE_INTEGER has the same range as PLS_INTEGER and has a NOT NULL constraint. It differs significantly from PLS_INTEGER in its overflow semantics. If you know that a variable will never have the value NULL or need overflow checking, declare it as SIMPLE_INTEGER rather than PLS_INTEGER .”
May 12
Algorithm Complexity Notations and Comparisons:
Ref: https://www.freecodecamp.org/news/big-o-notation-why-it-matters-and-why-it-doesnt-1674cfa8a23c/
May 12
The complexity here is: 3n+2 i.e. O(n)
Ref: https://www2.cs.sfu.ca/CourseCentral/125/johnwill/Packet06.pdf
