Update embedded select oracle

When repository XML data is stored object-relationally or as binary XML, queries that use fn:doc and fn:collection are evaluated functionally; that is, they are not optimized to access the underlying storage tables directly.

To improve the performance of such queries, you must link them to the actual database tables that hold the repository data being queried. You can do that in either of the following ways:. These SQL functions reference repository resources in a performant way.

Both methods have the same effect. Oracle recommends that you use the ora:defaultTable pragma because it lets you continue to use the XQuery standard functions fn:doc and fn:collection and it simplifies your code. You can use Oracle XQuery extension-expression pragma ora:defaultTable to improve the performance of querying repository data. Oracle XQuery extension-expression pragma ora:defaultTable lets you specify the default table used to store repository data that you query.

Example illustrates this; the query is rewritten automatically to what is shown in Example For clarity of scope Oracle recommends that you apply pragma ora:defaultTable directly to the relevant document or collection expression, fn:doc or fn:collection , rather than to a larger expression.

XQuery function fn:data is used here to atomize its argument, in this case returning the XMLRef node's typed atomic value. In Example , the various FLWOR clauses perform these operations: The outer for iterates over the sequence of XML elements returned by fn:collection : each element corresponds to a row of relational table oe. See Also: Example for the execution plan of Example The result is shown here pretty-printed, for clarity.

This produces the following result. McCain 32 rows selected. Place the text that follows the semicolon on the same line. McEwen 9 Ellen S. Abel 4 Sarah J. Bell 13 William M. Smith 7. XMLType; import java. Data; using System. Text; using System. IO; using System. Xml; using Oracle. Client; using Oracle. ToString ; cmd. Add " :nbitems ", OracleDbType. Int16, 3, ParameterDirection. Input ; cmd. Add " :partid ", OracleDbType.

Varchar2, "", ParameterDirection. ExecuteReader ; dr. WriteLine xml. Value ; xml. Dispose ; con. Close ; con.

Updates for non-schema-based documents stored as binary XML can be made in a piecewise manner. See Also: Example Note: Be aware that using XQuery Update to update XML schema-based data results in an error being raised if you try to store the updated data back into an XML schema-based column or table.

Example Optimization of XMLQuery over Relational Data Here again is the query of Example , together with its execution plan, which shows that the query has been optimized. Example Optimization of XMLTable over Relational Data Here again is the query of Example , together with its execution plan, which shows that the query has been optimized.

Use the Oracle XQuery extension-expression pragma ora:defaultTable. These two methods are illustrated in the examples of this section. The cursor can only move forward in the active set. If you want to change the active set, you must assign new values to the input host variables in the query associated with the cursor, then re-OPEN the cursor. As the next example shows, you can FETCH from the same cursor using different sets of output host variables.

The status of the output host variables is indeterminate in this case. To reuse the cursor, you must reOPEN it. When a cursor is closed, parse locks are released. If necessary, you can reOPEN a cursor with new values for the input host variables, for example. The cursor must be open and positioned on a row.

The program displays the names and hire dates of all employees that are in departments with numbers greater than Each SQL statement results in another call to the server and higher overhead. This minimizes communication between your application and Oracle. Furthermore, if a column definition changes, the variable declaration changes accordingly and automatically.

This provides data independence, reduces maintenance costs, and allows programs to adapt as the database changes. Instead, you can use a cursor FOR loop that implicitly declares its loop index as a record, opens the cursor associated with a given query, repeatedly fetches data from the cursor into the record, then closes the cursor. In the example above, you reference the comm field in the emprec record by typing emprec.

Generally, you use a procedure to perform an action and a function to compute a value. Procedures and functions provide extensibility. You use parameter modes to define the behavior of formal parameters. An IN parameter lets you pass values to the subprogram being called. An OUT parameter lets you return values to the caller of a procedure. An IN OUT parameter lets you pass initial values to the procedure being called and return updated values to the caller.

Packages can be compiled and stored in an Oracle database, where their contents can be shared by many applications. As in Ada, packages usually have two parts: a specification and a body. The specification is the interface to your applications; it declares the types, constants, variables, exceptions, cursors, and subprograms available for use. The body defines cursors and subprograms and so implements the specification. Specify the name of the partition or subpartition within table targeted for updates.

You need not specify the partition name when updating values in a partitioned table. Specify a complete or partial name of a database link to a remote database where the object is located.

You can use a database link to update a remote object only if you are using Oracle Database distributed functionality. If you omit dblink, then the database assumes the object is on the local database.

Regardless of its form, it must return a collection value—that is, a value whose type is nested table or varray. This process of extracting the elements of a collection is called collection unnesting. For example, you could roll up four quarterly sales tables into a yearly sales table.

Specify a correlation name alias for the table, view, or subquery to be referenced elsewhere in the statement. Specify the name of a column of the object that is to be updated. Tony Andrews Tony Andrews k 20 20 gold badges silver badges bronze badges. Just updating the result of a select statement. There is also a from which also returning of values called Update with returning clause And some specifics for updates with nested tables.

Thilo k 94 94 gold badges silver badges bronze badges. Thanks for comments, I thought this was standard Sql ID SET t1. Andomar Andomar k 44 44 gold badges silver badges bronze badges. Are you sure that works? Using dpriver. I'm not sure it is standard SQL either. Sign up or log in Sign up using Google.

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