What is decode in PLSQL?

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.

Can we use decode in PLSQL block?

Since we can’t use decode directly in pl/sql, the plan is to use ‘select decode() into variable from dual’.

How does decode works 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.

What is difference between decode and case 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.

Can we use case in decode?

The case statement you can use in PL SQL but as decode is function then you require to use only in SQL statements. You can also use in PLSQL but not like Case statement. You always need to use it in select statement.

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.

Is decode faster than case when?

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. To clarify: DECODE can be faster than a CASE, but a simple CASE may be translated internally to DECODE, yielding the same performance.

Can we use decode without select statement?

You can not use DECODE in PL/SQL directly. If want to use it in PL/SQL, it should be part of SELECT statement.

Can we use decode in case statement?

What is a cursor in PL SQL?

A cursor is a pointer that points to a result of a query. PL/SQL has two types of cursors: implicit cursors and explicit cursors.

How to declare an explicit cursor in SQL Server?

Before using an explicit cursor, you must declare it in the declaration section of a block or package as follows: First, specify the name of the cursor after the CURSOR keyword. Second, define a query to fetch data after the IS keyword. Before start fetching rows from the cursor, you must open it. To open a cursor, you use the following syntax:

How do you open a cursor in SQL?

To open a cursor, you use the following syntax: OPEN cursor_name; Code language: SQL (Structured Query Language) (sql) In this syntax, the cursor_name is the name of the cursor declared in the declaration section. When you open a cursor, Oracle parses the query, binds variables, and executes the associated SQL statement.

What are the different types of cursors in SQL?

1 Implicit cursors. Whenever Oracle executes an SQL statement such as SELECT INTO, INSERT, UPDATE, and DELETE, it automatically creates an implicit cursor. 2 Explicit cursors. An explicit cursor is an SELECT statement declared explicitly in the declaration section of the current block or a package specification. 3 PL/SQL cursor example.