New features in plsql for oracle database 10g release 2 10. Strong ref cursor with user defined record datatype. Each ref cursor query is associated with a plsql function that returns a strongly typed ref. Net type for the ref cursor type this section discusses the following aspects of using ref cursor and oraclerefcursor objects obtaining an oraclerefcursor. In the previous tutorial we learnt how to create a plsql strong ref cursor using table based record datatype variable. Ask tom difference between cursor and a ref cursor oracle. After many attempts, had to use a collection as input parameter, and fetch. The fetch statement retrieves rows of data from the result set of a multirow query. Moreover such ref cursors can only be used with some select statements. How cursor variables are defined is the topic of the next section. It is up to the calling code to manage the cursor once it has been opened. Using plsql stored procedures and ref cursors oracle.
The ref cursor is a datatype in the oracle plsql language. For example, you can declare a cursor variable in a plsql host environment such as an oci or proc program, then pass it as an input host variable bind variable to plsql. Until oracle has retrieved all the rows then by definition it does not have an accurate record of how many there are. We could use any cursor variable, a variable of type ref cursor, or output parameter from a procedure, but the function will make life easy for the examples. The oracle ref cursor is a pointer data types that allows you to quickly reference any cursor result usually an internal plsql table array with data values kept in superfast ram.
Oracle tutorialonlinetrainingplsqlref cursor part2. Different behavior for ref cursor between oracle 10g and. Run operations using ref cursors in oracle database using the wcf service model. Oracle 8i oracle 9i oracle 10g oracle 11g oracle 12c oracle c oracle 18c oracle 19c miscellaneous plsql sql oracle rac oracle apps weblogic linux mysql. I am using oracle sql developer, but i am having an issue seeing results from a package that returns a ref cursor. Ref cursor s are represented through the oraclerefcursor odp. So far in this series we have covered the concepts of strong as well as weak ref cursor. Although this reduces the chances of runtime errors.
How to convert oracle cursor when migrating to sql server. Oracle tutorialonlinetrainingplsql ref cursor part. Operations on functions and procedures with ref cursor. I have a requirement where i should pass cursor variable as input parameter to a procedure and fetch data from that in the procedure. A ref cursor being a pointer to an open cursor used to send an open cursor as an out argument to the client app to loop through the record.
There are two types of cursor variable 1week ref cursor. Oracle 12c introduced implicit statement results, and sqlplus and sqlcl display the contents of implicit statement. There is no dependency on its return structure, thus making it open to all select. Any ref cursor which has a fixed return type is called a strong ref cursor. This may be a dumb question, but ive never got my head round the strange tablecast. Aug 06, 2015 how to test a oracle stored procedure with ref cursor from sqlplus or sql developer. Run operations using ref cursors in oracle database using the. There are several ways to return query results from an oracle database to a client application, using oracle data provider for. This example executes a plsql stored procedure that returns two ref cursor parameters, and fills a dataset with the rows that are returned. You cannot define the same cursor more than stead you can only use it.
Technically, under the covers, at the most basic level, they are the same. Different from implicit and explicit cursors, a cursor variable is not tied to any specific query. Normally a cursor is a static thing, it points to a query. Jun 27, 2012 i doubt something like this would be feasible.
The cursor variable is specified as an in out parameter so that the result set is made available to the caller of the procedure. There he asked one question as what is the difference between cursor and ref cursor, and when would you appropriately use each of these. When a ref cursor is defined without a return type, it is called as a weakly typed dynamic ref cursor. The ref cursor is a data type in the oracle pl sql language. There is no real difference, in fact, deep down in the data dictionary, we have this definition. For how many years have you been working with physical servers that are starving your database of the memory necessary to deploy important new performance features such as the result cache, memoptimize pool, in memory aggregation, in memory column store, and full database caching. Plsql weak ref cursors oracle plsql tips by boobal ganesan.
Application development tools such as oracle forms, which have a plsql engine, can use cursor variables entirely on the client side. For example, a procedure can open a cursor and use a ref cursor to return a subset of the records to the caller procedure or anonymous plsql block. A query work area remains accessible as long as any cursor variable points to it, as you pass the value of a cursor variable from one scope to another. For the weak ref cursor the structure does not need to be known at compile time. It declares a weak ref cursor and that too without declaring the ref pointer type. Strong plsql ref cursors burleson oracle consulting. What is the difference between a normal cursor and a ref. Strong ref cursor and weak ref cursor for the strong ref cursor the returning columns with datatype and length need to be known at compile time. As other answers pointed out they are memory structures used to temporarily store and iterate through a query result set in plsql. The example below uses a ref cursor to return a subset of the records in the emp table. For example, an oci client, oracle forms application, and oracle database server can all refer to the same work area. A ref cursor is a plsql data type that represents a pointer to a serverside result set generated by executing a query. In apex, i tried the forms on procedure option but was struggling with it. I created a store proc where i am giving date as in parameter and ref cursor is an out parameter.
Crystal report using ref cursor ole db failed to retrieve. I have written a function which is returning the ref cursor. Suggestions, comments, feedbacks and referrals are highly appreciated. Meaning that a cursor variable can be opened for any query. The refcursor declared in this programs scope is never opened as when it is assigned to the same refcursors variable in the out parameter, the information of the cursor variable from the server program is copied into this variable, thus making it its alias. Plsql cursor variables with ref cursor oracle tutorial.
It doesnt reference a cursor result as there are only results as the data is fetched through the cursor pointer. Pl sql ref cursor and oraclerefcursor oracle help center. Run operations using ref cursors in oracle database using. It allows a user to pass this reference to the same cursor among all the programs that need access to the cursor. Basically, the procedure opens a reference cursor, updates a table then completes. However, that said i fail to see why you having to select in one stored procedure, to put the data into a global temporary table and then just join. Plsql strong ref cursor with user defined record datatype. A ref cursor can be opened on the server and passed to the client as a unit rather than fetching one row at a time. Operations on functions and procedures with ref cursor parameters in oracle database. If so, could anyone help me in sorting out the way.
Plsql ref cursor and oraclerefcursor oracle help center. Different types of cursors in plsql oracle live sql. Hi tom, feels good that i got a chance to ask you a question. Defining cursor variables ref cursor return clause. Introduction to plsql ref cursors in oracle database. This example demonstrates how to define and open a ref cursor variable, and then pass it as a procedure parameter. Net type for the ref cursor type this section discusses the following aspects of using the ref cursor data type and oraclerefcursor objects. Net type for the ref cursor type this section discusses the following aspects of using the ref cursor datatype and oraclerefcursor objects obtaining an. A ref cursor is a datatype that holds a cursor value in the same way that a varchar2 variable will hold a string value. A ref cursor can have an arbitrary query associated with it. Net to create powerful, flexible, and scalable applications. It represents a cursor or a result set in oracle database.
To use these examples, you may need to create the oracle tables, and you must create a plsql package and package body. The name of this context area is same as the cursor name. In essence, a ref cursor is a pointer or a handle to a result set on the database. Ref cursors may be dynamically opened or opened based on logic. It represents a cursor or a result set in the oracle database. Ask tom how to test a function returning a ref cursor. Oracle plsql ref cursors ref cursors a ref cursor or cursor variable is just a reference or a handle to a static cursor. The oracle docs specify that the open statement only identifies the result set, but does not retrieve the rows, which happens only with every call to the fetch statement.
Difference between cursor and a ref cursor oracle ask tom. Archive for the ref cursor tag reference cursors why, when, and how. A ref cursor is a variable, defined as a cursor type, which will point to, or reference a cursor result. A strongly bound ref cursor is bound with the same structure that is used by the outputted select statement in the oracle stored procedure. In addition, the result of select statements datatype should match with the one that was fixed during the strong cursor s declaration. Using ref cursor in oracle sql developer stack overflow. Oracle database tips by donald burlesonapril 18, 2015. Sys ref cursor is an oracle built in cursor variable. Different behavior for ref cursor between oracle 10g and 11g when unique index present. Ref cursors are one of the most powerful, flexible, and scalable methods for returning query results from an oracle database to a client application. Ref cursor input yref cursor can be used to fetch the input rows. You can fetch rows one at a time, several at a time, or all at once. Or you can use a regular cursor for loop, which implicitly opens a cursor, not a ref cursor.
The documentation team has to enter the date and the changes made on the respective date will be displayed on apex. Is there any way to call this function with jpa or hibernate. I have some data in a header table and a bunch of child tables. You use the open, fetch, and close statements to control a cursor. You can open a ref cursor, dynamically or not, and fetch from it within a loop. 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. The discussion made me reflect if there were a couple simple rules for using reference cursors. This microsoft visual basic example executes a plsql stored procedure that returns a ref cursor parameter, and reads the value as an oracledatareader. 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 plsql data type whose value is the memory address of a query work area on the database. The ref cursor xe ref cursor can be assigned to other ref cursor variables.
Using cursor variables ref cursors posted by himanshu karki at 7. Thats it for this tutorial on the introduction to plsql ref cursors in oracle database. First, my question is passing ref cursor variables as actual parameters valid in oracle. Plsql composite data type collections associative array, varray and nested tables kafka java producer and consumer.
I tried to call it as a native query, but it didnt work. A week or two ago, i noticed a discussion on the oracle technical network forum that asked some questions about reference cursors. Opening the cursor will instruct the plsql to allocate the memory for this cursor. When declaring the ref cursor in an oracle package, the ref cursor may be strongly bound or it may be weakly bound. Declaring the cursor simply means to create one named context area for the select statement that is defined in the declaration part. A cursor variable is a variable that references to a cursor. The ref cursor can be assigned to other ref cursor variables. This variable is then looped for processing the returned result set as shown in. As we learnt in the introduction to the ref cursor that there are three types of plsql ref cursor in oracle database strong ref cursor. Mostly it is used as a generic cursor which can be passed as an argument to a stored sub program. I see no need for opening a ref cursor, dynamically or otherwise, so i would just use a regular cursor for loop. Strong ref cursor and weak ref cursor what is the difference between cursor and ref cursor, and when would you appropriately use each of these.
A ref cursor is a datatype that holds a cursor value in the same way that a varchar2 variable will hold a string value a ref cursor can be opened on the server and passed to the client as a unit rather than fetching one row at a time. In 10g the cursor will contain the expected results but in 11g the cursor will be empty. A ref cursor is a plsql data type whose value is the memory address of a query work area on the database. I assume this to mean that open fetches the result set of the query into some memory space in the server probably an area not part of the plsql memory space, after which every. To read more about ref cursor i have created a package to explain few different ref cursor examples. Strongly typed the ref cursor type is restricted to an individual return type using the return clause. One can use a ref cursor as target of an assignment, and it can be passed as parameter to other program units. Posted in oracle, plsql cursor variable ref cursor ref cursors refcursor reference cursor weak and strong ref cursor published by sqlandplsql to learn more about the oracle, sql, pl sql, performance tuning, database modeling, ubuntu, mysql etc. The ref cursor is a data type in the oracle plsql language. Net framework data provider for oracle supports the oracle ref cursor data type.
Using oracle table functions shiby thomas oracle corporation. There i demonstrated the use of strong ref cursor to handle the data from all. 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. Cursor variables are defined using a ref cursor type. Dec 20, 2016 i hope before knowing about ref cursors you would have a fair idea of what cursors in general are.
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