How do you handle the greatest NULL in Oracle?
Substitute any NULL values with a date that is earlier than any date that is likely to occur in your tables. SELECT GREATEST(NVL(A,TO_DATE(’01/01/1800′,’MM/DD/YYYY’)), NVL(B,TO_DATE(’01/01/1800′,’MM/DD/YYYY’))) AS OUTPUT FROM …
What does => mean in PL SQL?
That is the keyword/value notation for passing parameters to a PL/SQL procedure or function. The left side is the name of the parameter, the right is the value being passed. It’s useful when you don’t want to keep to a specific ordering of parameters, or for self-documenting code.
Can we compare NULL values in Oracle?
Because null represents a lack of data, a null cannot be equal or unequal to any value or to another null. However, Oracle considers two nulls to be equal when evaluating a DECODE function.
What happens if a condition in an if statement in PL SQL evaluates to NULL?
If the condition evaluates to FALSE or NULL, the code is not executed.
How do you find the greatest number in Oracle?
Oracle / PLSQL: GREATEST Function
- Description. The Oracle/PLSQL GREATEST function returns the greatest value in a list of expressions.
- Syntax. The syntax for the GREATEST function in Oracle/PLSQL is: GREATEST( expr1 [, expr2.
- Returns.
- Note.
- Applies To.
- Example.
What is least and greatest in SQL?
Purpose of the Oracle GREATEST and LEAST Function The Oracle GREATEST function returns the “greatest” or largest value in a set of values that you provide to it. The Oracle LEAST function returns the “least” or smallest value in a set of values that you provide to it, and it’s the opposite of the GREATEST function.
What does @? Mean in Oracle?
Means select not from the local question_answer table, but from the table on the db designated as abcd . The keyword to google for is dblink.
IS null function in PLSQL?
Description. The Oracle IS NULL condition is used to test for a NULL value. You can use the Oracle IS NULL condition in either a SQL statement or in a block of PLSQL code.
Is null not working in PLSQL?
Description. The Oracle IS NOT NULL condition is used to test for a NOT NULL value. You can use the Oracle IS NOT NULL condition in either a SQL statement or in a block of PLSQL code.
How do you handle null values in PLSQL?
Handling NULL values Related Examples
- COALESCE to return the first non-NULL value.
- Columns of any data type can contain NULLs.
- Empty strings are NULL.
- NVL to replace null value.
- NVL2 to get a different result if a value is null or not.
- Operations containing NULL are NULL, except concatenation.
How do I check if a variable is null in PLSQL?
It takes any number of arguments, and returns the first one which is not NULL. If all the arguments passed to COALESCE are NULL, it returns NULL. In contrast to NVL , COALESCE only evaluates arguments if it must, while NVL evaluates both of its arguments and then determines if the first one is NULL, etc.
How do you find the greatest number in PL SQL?
FIND THE GREATES AMONG THREE NUMBER put_line(‘Enter c:’); c:=&C if (a>b) and (a>c) then dbms_output. put_line(‘A is GREATEST’||A); elsif (b>a) and (b>c) then dbms_output. put_line(‘B is GREATEST’||B); else dbms_output.
What is the difference between Max and greatest in Oracle?
Both MAX and GREATEST will return one result, but MAX is an aggregate function and GREATEST is not. GREATEST can return multiple rows. It will return one row for each row of data you query as it is not an aggregate function.
Is there a greatest function in SQL?
The GREATEST function requires at least one argument and supports no more than 254 arguments. Each expression can be a constant, variable, column name or function, and any combination of arithmetic, bitwise, and string operators. Aggregate functions and scalar subqueries are permitted.
What is symbol in PL SQL?
A line of PL/SQL text contains groups of characters known as lexical units, which can be classified as follows: delimiters (simple and compound symbols) identifiers, which include reserved words….Delimiters.
| Symbol | Meaning |
|---|---|
| ~= | relational operator |
| ^= | relational operator |
| <= | relational operator |
| >= | relational operator |
How do you handle NULL values in PLSQL?
How do I check if a variable is NULL in PLSQL?