Which one is better case or decode in Oracle?
CASE is better than DECODE because it is easier to read, and can handle more complicated logic. As far as performance goes, there is minimal difference between CASE and DECODE, so it should not be a factor in your decisions.
What is decode in SQL Oracle?
In Oracle, DECODE function allows us to add procedural if-then-else logic to the query. DECODE compares the expression to each search value one by one. If expression is equal to a search, then the corresponding result is returned by the Oracle Database. If a match is not found, then default is returned.
Can I use decode in PL SQL?
The DECODE function can be used in Oracle/PLSQL. You could use the DECODE function in a SQL statement as follows: SELECT supplier_name, DECODE(supplier_id, 10000, ‘IBM’, 10001, ‘Microsoft’, 10002, ‘Hewlett Packard’, ‘Gateway’) result FROM suppliers; The DECODE function will compare each supplier_id value, one by one.
What is the output of select decode null null 1 0 from dual?
Oracle DECODE Function with NULL Values It treats a NULL expression and NULL search as equal (so NULL == NULL). So, this example will return 1: SELECT DECODE(NULL, NULL, 1, 0) FROM DUAL; The CASE statement treats NULL values as not equal, so this is an important distinction when working with this function.
Is decode faster than case Oracle?
From performance perspective, In Oracle decode and CASE does not make any difference. But in Exadata , Decode is faster than CASE. The Decode operation is done at storage Server level where the data is present BUT CASE is done at DB Instance level which receives data from DB storage Level.
What is the difference between coalesce and NVL?
NVL and COALESCE are used to achieve the same functionality of providing a default value in case the column returns a NULL. The differences are: NVL accepts only 2 arguments whereas COALESCE can take multiple arguments. NVL evaluates both the arguments and COALESCE stops at first occurrence of a non-Null value.
What is SQL decode?
Introduction to SQL DECODE() DECODE function in Standard Query Language (SQL) is used to add procedural IF – THEN – ELSE like statements to a query. It compares a given expression with each search value one by one and returns a result on the basis of outcomes received from the comparison.
What is the difference between decode and case?
DECODE performs an equality check only. CASE is capable of other logical comparisons such as < > etc. It takes some complex coding – forcing ranges of data into discrete form – to achieve the same effect with DECODE.
Can we use decode inside decode?
It is possible to use DECODE, but you’d have to use nested DECODEs and you’d end up with something that’s much harder to read, understand and therefore maintain.
What is the difference between decode and case in SQL?
CASE is a statement while DECODE is a function. CASE can work with logical operators other than ‘=’ : DECODE performs an equality check only. CASE is capable of other logical comparisons such as < ,> ,BETWEEN , LIKE etc.
What is the difference between NVL and nvl2?
What is the difference between nvl and nvl2? Answer: The nvl function only has two parameters while the nvl parameter has three arguments. The nvl2 like like combining an nvl with a decode because you can transform a value: NVL ( expr1 , expr2 ): If expr1 is null, then NVL returns expr2.
Should I use NVL or coalesce?