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What is decode function in Oracle?

What is decode function in Oracle?

DECODE compares expr to each search value one by one. If expr is equal to a search , then Oracle Database returns the corresponding result . If no match is found, then Oracle returns default . If default is omitted, then Oracle returns null.

Can we use decode in group by in Oracle?

Oracle DECODE with GROUP BY example The following statement illustrates how to use the DECODE() function in the GROUP BY clause. It returns the number of products whose list prices are higher than, equal to, and less than the average list price.

How decode is used in SQL with example?

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. If default is omitted, then Oracle returns null.

How do I decode a value in SQL query?

The basic syntax for writing DECODE function in SQL is as follows: DECODE (expression , search_1, result_1[, search_2, result_2].,[,search_n,result_n] [, default]); The parameters used in the above mentioned syntax are: expression: expression argument is the value which is to be searched and compared with.

Which 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 the difference between substr and Instr?

Answers. The substr functions allows you to extract a substring from a string. The instr function returns the location of a substring in a string. position and length of characters to be fetched.

What is difference between Case and decode in Oracle?

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 grouping function in SQL?

The SQL GROUPING is one of the Aggregate Functions, which is used to indicate whether the specified column in a GROUP BY Clause aggregated or not. This Grouping function will return one for aggregated and zero for not aggregated.

What are analytical functions in Oracle?

Analytical functions are used to do ‘analyze’ data over multiple rows and return the result in the current row. E.g Analytical functions can be used to find out running totals, ranking the rows, do some aggregation on the previous or forthcoming row etc.

Which is better decode or case in Oracle?

Is decode faster than case in 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.