What is ref cursor in Oracle PL SQL with example?

What is ref cursor in Oracle PL SQL with example?

A REF CURSOR is a PL/SQL data type whose value is the memory address of a query work area on the database. In essence, a REF CURSOR is a pointer or a handle to a result set on the database. REF CURSOR s are represented through the OracleRefCursor ODP.NET class.

What is dynamic cursor in Plsql?

Specifies an identifier for a cursor variable that was previously declared within a PL/SQL context. FOR dynamic-string. Specifies a string literal or string variable that contains a SELECT statement (without the terminating semicolon). The statement can contain named parameters, such as, for example, :param1 .

What is dynamic cursor in Oracle?

It supports for only value,in the way you used.. You need to specify it like IN (var1, var2) ; Without knowing you , you have used bind variables. One workaround is use REFCURSOR By forming a query string dynamically. DECLARE VAR1 VARCHAR2(500); CUR1 SYs_REFCURSOR; QUERY_STRING VARCHAR2(2000) := ‘SELECT T.

What is the difference between cursor and ref cursor?

A cursor is really any SQL statement that runs DML (select, insert, update, delete) on your database. A ref cursor is a pointer to a result set. This is normally used to open a query on the database server, then leave it up to the client to fetch the result it needs.

What are the restrictions of ref cursor in PL SQL?

The user-defined REF CURSOR type can be defined by executing the TYPE declaration in a PL/SQL context. After the type has been defined, you can declare a cursor variable of that type. Restriction: REF CURSOR types can be declared only within a package and are not supported in routines, triggers, or anonymous blocks.

What is ref cursor with example?

A ref cursor is a variable, defined as a cursor type, which will point to, or reference a cursor result. The advantage that a ref cursor has over a plain cursor is that is can be passed as a variable to a procedure or a function. The REF CURSOR can be assigned to other REF CURSOR variables.

What is dynamic SQL in Oracle with example?

For example, dynamic SQL lets you create a procedure that operates on a table whose name is not known until runtime. Oracle includes two ways to implement dynamic SQL in a PL/SQL application: Native dynamic SQL, where you place dynamic SQL statements directly into PL/SQL blocks.

What is dynamic SQL example?

For example, dynamic SQL lets you create a procedure that operates on a table whose name is not known until runtime. In past releases of Oracle, the only way to implement dynamic SQL in a PL/SQL application was by using the DBMS_SQL package.

What is the difference between static and dynamic cursor?

A Static Cursor doesn’t reflect data changes made to the DB once the ResultSet has been created whereas a Dynamic Cursor reflects the changes as and when they happen. A Static Cursor is much more performant than a Dynamic Cursor as it doesn’t require further interaction with the DB server.

Can you have two stored functions with the same name?

No, you can’t. That means only packaged function/procedures can be overloaded, and we can’t create two stored functions with the same name as seperate objects in the database.

What is Dynamic SQL example?

How do I run a dynamic SQL query?

Executing dynamic SQL using sp_executesql sp_executesql is an extended stored procedure that can be used to execute dynamic SQL statements in SQL Server. we need to pass the SQL statement and definition of the parameters used in the SQL statement and finally set the values to the parameters used in the query.

How do I write a dynamic SQL query?

Dynamic SQL – Simple Examples

  2. @sql NVARCHAR(MAX),
  3. @id NVARCHAR(MAX);
  4. — run query using parameters(s)
  5. SET @id = N’2′;
  6. SET @sql = N’SELECT id, customer_name FROM customer WHERE id = ‘ + @id;
  7. PRINT @sql;
  8. EXEC sp_executesql @sql;

What is the difference between stored procedure and dynamic SQL?

Stored Procedures outperform dynamic SQL in almost all aspects. They are faster, secure, and easy to maintain, and require less network traffic. As a rule of thumb, stored procedures should be used in scenarios where you don’t have to modify your queries and your queries are not very complex.

Can a trigger and procedure have same name?

No. This is clearly stated in the MSDN documentation: Procedure names must comply with the rules for identifiers and must be unique within the schema.

Can we call a stored procedure inside a stored procedure?

Yes , Its easy to way we call the function inside the store procedure. for e.g. create user define Age function and use in select query.

What is dynamic query in SQL Server with example?

Dynamic SQL – Simple Examples Let’s start with the simplest possible example. It’s pretty obvious that this query is exactly the same as the simple SELECT * FROM customer; query. The sp_executesql procedure takes the SQL string as a parameter and executes it. Since it’s the Unicode string we use the N prefix.

Can we use temp table in dynamic SQL?

If you would like to store dynamic sql result into #temporary table or a a table variable, you have to declare the DDL firstly which is not suitable for your situation. Example of temporary table: if object_id(‘tempdb.. #t1’) is not null drop table #t1.

Why stored procedure is faster than query?

Stored procedures are precompiled and optimised, which means that the query engine can execute them more rapidly. By contrast, queries in code must be parsed, compiled, and optimised at runtime. This all costs time.

Can a trigger call a stored procedure?

A: Yes, we can call stored procedure inside the trigger.

What is REF CURSOR type in PL/SQL?

PL/SQL has two forms of REF CURSOR typeS: strong typed and weak typed REF CURSOR. The following shows an example of a strong REF CURSOR. DECLARE TYPE customer_t IS REF CURSOR RETURN customers%ROWTYPE; c_customer customer_t; Code language: SQL (Structured Query Language) (sql)

How to declare a cursor variable in PL/SQL?

To declare a cursor variable, you use the REF CURSOR is the data type. PL/SQL has two forms of REF CURSOR typeS: strong typed and weak typed REF CURSOR.

Why are cursor variables called strong typed REF CURSOR?

This form of cursor variable called strong typed REF CURSOR because the cursor variable is always associated with a specific record structure, or type. And here is an example of a weak typed REF CURSOR declaration that is not associated with any specific structure:

How to return the data as a ref_Cur in dynamic SQL?

Answer: Here is an example script that performs dynamic SQL and returns the data as a ref cursor. — First, we declare the package specs create or replace package test_pack is type ref_cur is ref cursor; procedure printme(ref_var ref_cur); end;