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keyword and parameter descriptionlabelnamethis is an undeclared identifier which optionally labels the plsql block when used labelname should be
expressionthis is a randomly complex combination of constants variables literals operators amp function calls the simplest expression consists of a
using pragma restrictreferencesthe function called from the sql statements should obey certain rules meant to control the side effects to check for
using invoker rightsby default the stored procedure executes with the privileges of its definer not its invoker these procedures are bound to the
remote operationsas the illustration shows below the plsql subprograms can execute the dynamic sql statements which refer to the objects on a remote
pass the nulls to a dynamic sqlpassing nullsassume that you want to pass the nulls to a dynamic sql statement for illustration you may write the
using cursor attributesevery cursor has 4 attributes notfound found isopen and rowcountif appended to the cursor name they return the helpful
benefit of the dynamic sqlthis part shows you how to take full benefit of the dynamic sql and how to keep away from some of the common
parameter modesyou do not require to specify a parameter mode for the input bind arguments those used for illustration in the where clause as the
need for dynamic sqlyou need dynamic sql in the situations as follows1 you would like to execute a sql data definition statement like create a data
dynamic sqlthe most plsql programs do a predictable specific job for illustration a stored procedure may accept an employee number and salary
deleting objectsyou can use the delete statement to eradicate objects from an object table to eradicate objects selectively you use the where clause
updating objectsto change the attributes of objects in an object table you can use the update statement as the illustration below showsbeginupdate
inserting objectsyou can use the insert statement to add objects to an object table in the illustration below you insert a person object into the
using operator derefyou cannot navigate through refs within the plsql procedural statements rather than you should use the operator deref in the sql
using operator refyou can retrieve refs by using the operator ref that like value takes as its argument a correlation variable in the illustration
using operator valueas you may expect the operator value returns the value of an object the value takes its argument a correlation variable for
selecting objectssuppose that you have run the sqlplus script below that creates object type person and object table persons and that you have
manipulating objectsyou can use an object type in the create table statement to indicate the datatype of a column when the table is created once you
calling constructorsthe calls to a constructor are allowed wherever the function calls are allowed similarly to the functions a constructor is called
accessing attributesyou can refer to an attribute only by its name not by its position in the object type to access or modify the value of an
initializing objectstill you initialize an object by calling the constructor for its object type the object is automatically null that is the object
declaring objectsyou can use the object types wherever built-in types like char or number can be used in the block below you can declare object r of
declaring and initializing objectsan object type is once defined and installed in the schema you can use it to declare the objects in any plsql
map and order methodsthe values of the scalar datatype like char or real have a predefined order that allows them to be compared while the instances