What is difference between cursor and ref cursor in Oracle?
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.
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 difference between cursor and for loop?
Unlike an implicit cursor, you can reference an explicit cursor or cursor variable by its name. Therefore, an explicit cursor or cursor variable is called a named cursor. The cursor FOR LOOP statement lets you run a SELECT statement and then immediately loop through the rows of the result set.
What is dynamic query in Oracle?
Dynamic SQL is a programming technique that enables you to build SQL statements dynamically at runtime. You can create more general purpose, flexible applications by using dynamic SQL because the full text of a SQL statement may be unknown at compilation.
Can we write 2 procedures with same name in Oracle?
You can use the same name for several different subprograms as long as their formal parameters differ in number, order, or datatype family. For an example of an overloaded procedure in a package, see Example 9-3.
Can a trigger and procedure have same name in same schema?
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.
What is ref cursor in Oracle?
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 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.
Which is faster cursor or loop?
While SQL While loop is quicker than a cursor, reason found that cursor is defined by DECLARE CURSOR. Every emphasis of the loop will be executed inside system memory and consuming required server assets.
What is difference between FOR LOOP and cursor in Oracle?
Why do we use dynamic SQL?
Dynamic SQL enables you to write application code that is reusable because the code defines a process that is independent of the specific SQL statements used. In addition, dynamic SQL lets you execute SQL statements that are not supported in static SQL programs, such as data definition language (DDL) statements.
Can Trigger and procedure have same name in same schema?
Can procedure in a package be overloaded?
Restrictions on Overloading You cannot overload subprograms whose parameters differ only in subtype. For example, you cannot overload procedures where one accepts an INTEGER parameter and the other accepts a REAL parameter, even though INTEGER and REAL are both subtypes of NUMBER and so are in the same family.
Can a trigger call a stored procedure?
A: Yes, we can call stored procedure inside the trigger.
Are stored procedures faster than triggers?
Often a stored proc doing the action directly along with the update,delete,insert would be more efficient than doing it in a trigger.
Is it possible to have a REF CURSOR with dynamic SQL?
Question: Is it possible to have a PL/SQL procedure that has dynamic SQL and uses a ref cursor? Can you show an example of a ref cursor with dynamic SQL? Answer: Here is an example script that performs dynamic SQL and returns the data as a ref cursor.
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;
What are ref cursors in Oracle?
Using REF CURSORs is one of the most powerful, flexible, and scalable ways to return query results from an Oracle Database to a client application. 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.
Why doesn’t the compiler validate the contract between the query and cursor?
Because the compiler cannot parse the string in the dynamic SQL statement. So it cannot assert that the columns in the query’s projection match in number and datatype the signature of the ref cursor. Consequently it cannot validate the contract between the ref cursor variable and the query.