What is the decode function in Oracle?

What is the decode function in 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.

What does (+) mean in Oracle?

Oracle outer join operator (+) allows you to perform outer joins on two or more tables. Quick Example: — Select all rows from cities table even if there is no matching row in counties table SELECT cities. name, countries.

What is sign in Oracle SQL?

SIGN returns the sign of n . This function takes as an argument any numeric datatype, or any nonnumeric datatype that can be implicitly converted to NUMBER , and returns NUMBER . For value of NUMBER type, the sign is: -1 if n <0. 1 if n >0.

Which is better decode or case in Oracle?

Answer: The difference between decode and case are straightforward. While the decode operator has been around since the earliest days of Oracle, the case operator was introduced in Oracle 8.1. 6. While d3code and case can be used interchangeably, the decode is more powerful because decode can change SQL results.

How do I use decode?

The DECODE function returns a value that is the same datatype as the first result in the list. If the first result is NULL, then the return value is converted to VARCHAR2. If the first result has a datatype of CHAR, then the return value is converted to VARCHAR2. If no matches are found, the default value is returned.

What are the 5 oracles?

The Five Oracles

• Dodona.
• Trophonius.
• Erythaea.
• Cumæ
• Delphi.

What is right join in Oracle?

What is a right outer join in Oracle? A RIGHT OUTER JOIN performs an inner join of two tables (supposed table A which writes before the join keyword and table B which writes after the join keyword in the SQL statement ) based on the condition specified after the ON keyword.

What is sign in SQL?

SIGN() function : This function in SQL Server is used to return the sign of the specified number. It returns 1 if the number is positive, -1 if the number is negative and 0 for zero number.

What does sign function do in Oracle?

Oracle SIGN() function This function is used to return the sign of a given number. This function takes as an argument any numeric data type and any nonnumeric data can also comes in the argument but that can be implicitly converted to number and returns number.

How do you decode a coded message?

To decode a message, you do the process in reverse. Look at the first letter in the coded message. Find it in the bottom row of your code sheet, then find the letter it corresponds to in the top row of your code sheet and write it above the encoded letter.

How do I use the decode() and sign() functions in Oracle?

This can be accomplished using the DECODE() function in combination with Oracles SIGN() function. The SIGN() function accepts a mathematical equation or number and returns a 1, 0, or -1 based on whether the solution is <0, =0 or <0. For example: SIGN(7-5) = 1.

How does the Oracle DECODE function handle null values?

As I mentioned above, the Oracle DECODE function is an exception to other functions in how it handles NULL values. It treats a NULL expression and NULL search as equal (so NULL == NULL). So, this example will return 1:

What is decdecode function in SQL Server?

DECODE function is used to perform procedural IF-THEN-ELSE logic in SQL. The function is a close relative of CASE statements. It is a built-in function in ORACLE / PL SQL database management servers.

How do I use The DECODE function with like?

The DECODE function is used to find exact matches. This is one of the drawbacks when comparing it to the CASE statement, as the CASE statement can perform more advanced checks. However, it is possible to use the Oracle DECODE function with LIKE. You can do this with a combination of the SIGN function and the INSTR function.