Programming Guide - Actian

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How You Can Manipulate Data in Dynamic FieldserrorsFor example, the following statement creates a dynamic expression (dexp)that contains the value of a cell in the Salary column of a table field namedtbl:declaredexp = DynExpr default null;enddeclaredexp = CurFrame.Scope.CreateDynExpr(string ='tbl[i].Salary');When the dynamic expression is used in a GetValue, SetValue, or Assignmethod invocation, the value of i must be a valid row number for thearray.The value of the string parameter is evaluated within the context of thenamed scope. In the previous statement, the dexp dynamic expression isvalid while the current frame is running. The scope in the followingstatement limits the dynamic expression to the current event block:declaredexp = DynExpr default null;enddeclaredexp = CurEventScope.CreateDynExpr(string ='tbl[i].Salary');Any attempt to use the dynamic expression after the event blockterminates causes a runtime error.(Optional.) Provdes the text of the error message. If the scope object onwhich the CreateDynExpr method is invoked is invalid, or the text specifiedin the string parameter cannot be compiled, the CreateDynExpr methodreturns a null.If compilation errors occur, the CreateDynExpr method creates a stringobject containing the errors and sets the variable specified by the errorsparameter (of StringObject data type) to point to that string object. If nocompilation errors occur, this parameter is set to null.The following statement creates a dynamic expression and sets the errorsparameter:declaredexp = DynExpr default null;enddeclaredexp = CurFrame.Scope.CreateDynExpr(string ='tbl[i].Salary', errors = byref(stringvar);If an error occurs creating the dexp dynamic expression, the stringvarvariable contains the error message in its Value attribute.386 <strong>Programming</strong> <strong>Guide</strong>
How You Can Manipulate Data in Dynamic FieldsHow You Can Set and Get Values with Dynamic ExpressionsYou can use the following methods to get and set values in the field referencedby a dynamic expression:• GetValue to obtain the value from the field• SetValue and Assign to change values in the fieldThe GetValue method reevaluates the expression that was specified when theDynExpr object was created and places the value of the dynamic expression inthe specified variable.For example, to get the value of a dynamic expression that was created for afield whose data type is money, create a money variable and invoke DynExpr'sGetValue method to get the value from the dynamic expression and load it intothe money variable.The following statement performs this operation:status = dexp.GetValue(value = byref(money_var));If the GetValue method succeeds, status is set to ER_OK; if it fails, it is set tosome other integer value.Setting a value in a dynamic expression works similarly. Use DynExpr'sSetValue method to load a value from a valid OpenROAD expression into adynamic expression.The following code sets the value of the dynamic expression from a variableparameter to the SetValue method:status = dexp.SetValue(value = money_var);Like the GetValue method, the SetValue method sets status to ER_OK ifsuccessful; if it fails, it sets status to some other integer value.The SetValue method is valid only if the expression specified when thedynamic expression was created was not a computed expression. TheGetValue method is valid only if the expression specified when the dynamicexpression was created represents a field or table field cell.You can get a value from a dynamic expression and assign a new one in asingle step using the Assign method. For an example of using the Assignmethod, see How You Can Get Values from Unknown Fields (see page 388).Creating Dynamic Frames 387
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Ingres OpenROAD ® 2006Programming
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ContentsChapter 1: Introduction 13I
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Using an Object-oriented Approach t
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How You Can Retrieve Array Informat
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Chapter 12: Managing Event Queues 3
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Chapter 17: Preprocessing Your 4GL
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Chapter 1: IntroductionThis section
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ConventionsConventionsThe following
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Your Support OptionsYour Support Op
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OpenROAD NamesThe rules for these n
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OpenROAD Names3. Enclosing field sc
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OpenROAD NamesThe following code ex
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VariablesThe following illustrates
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VariablesIn the first example, film
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VariablesOpenROAD checks references
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VariablesHow You Can Declare Dynami
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VariablesFor example, assume that y
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ExpressionsHowever, you cannot use
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ExpressionsThe general syntax for h
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ExpressionsCurSessionSpecifies, for
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ExpressionsString OperatorThe conca
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ExpressionsOperatorlikenot likeOper
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Expressions• You can use the esca
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ExpressionsBecause procedures can r
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System-defined FunctionsThis rule h
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System-defined FunctionsNameOperand
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System-defined FunctionsName Operan
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System-defined FunctionsNameshift(c
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System-defined FunctionsSome date f
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System-defined FunctionsThe followi
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System-defined FunctionsCount Funct
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System-defined FunctionsResult Data
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Chapter 3: Writing Scripts and Proc
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ScriptsDeclare local variables that
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ScriptsUserEventSpecifies a user ev
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ScriptsExample—Field and Menu Ite
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ProceduresOpenROAD lets you create
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ProceduresReturning from a Procedur
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ProceduresExample—Local Procedure
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Procedures4GL DataTypedatemoneyfloa
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Calling Procedures• In this call
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Calling ProceduresparameterAssigns
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How Procedure Handles Work (ProcHan
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Compiler LimitationsYou can avoid t
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How You Can Invoke FramesHow the Cu
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How You Can Invoke FramesHow You Ca
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How You Can Invoke FramesFor more i
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How You Can Invoke FramesFor exampl
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How You Can Invoke FramesIf the obj
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How You Can Invoke FramesHow You Ca
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How You Can Invoke Frames• Prompt
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How You Can Invoke FramesThe syntax
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How You Can Run Non-interactive App
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How You Can Reference ObjectsHow Yo
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How You Can Reference ObjectsHow Yo
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How You Can Reference ObjectsUse an
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Using an Object-oriented Approach t
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InheritanceClass RelationshipsYou c
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InheritanceYou can specify a user c
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InheritanceThe Terminate method is
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How You Can Create a User ClassWhen
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How You Can Create a User ClassHow
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How You Can Create a User Class3. G
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How You Can Create a User ClassTo e
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External ClassesHow You Can Use Ext
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External ClassesExample—ActiveX C
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How You Can Manipulate Objects Gene
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Overview of the OpenROAD System Cla
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How You Can Access a Database with
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How You Can Manage TransactionsHow
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How You Can Manage TransactionsDivi
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How You Can Manage TransactionsTo c
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How Programming for Multiple Sessio
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Handling Database ErrorsIn OpenROAD
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Handling Database ErrorsIf a databa
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Handling Database ErrorsFor example
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Handling Database Errorsbeginerr_no
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Arrays and Table Fields—Conceptua
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ArraysBecause an individual attribu
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ArraysDeclaring an array variable d
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ArraysThe following statement puts
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Arraysfor i = custtable.FirstRow to
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ArraysHow You Can Add Rows to an Ar
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ArraysThe inserted row is blank bec
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ArraysThe following code fragment i
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ArraysThese attributes are:AllRowsR
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ArraysAttributes used in a sort can
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ArraysThe format parameter can be a
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Table FieldsTable Fields and Associ
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Table FieldsThe following applicati
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Table FieldsThis syntax references
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Table FieldsFor example, the follow
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Table Field OperationsTable Field C
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Table Field OperationsHow You Can U
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Table Field OperationsWhen you use
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Table Field OperationsBiases can be
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Table Field OperationsThe following
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Table Field OperationsHow You Can T
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Table Field OperationsTableField Me
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Table Field OperationsFor example,
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Table Field OperationsControlling M
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CollectionsCollectionsA collection
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Collections// Open a workbook and p
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Listview_Treeview_DemoImport the De
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Listview FieldsListview FieldsA lis
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Listview FieldsextensionSpecifies a
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Listview FieldsImageIndexSpecifies
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TreeNode and Tree ClassesHeaderClic
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TreeNode and Tree ClassesMaintenanc
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Treeview FieldsHow You Can Build a
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Treeview FieldsThe second window is
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Treeview FieldsThe tree_ex2_class h
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Chapter 9: Working with Images and
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How You Can Work with ImagesThe fol
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How You Can Work with ImagesThe Col
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How You Can Work with ImagesThe Bit
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How You Can Work with Images5. Add
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How You Can Work with Text StringsD
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How You Can Work with Text StringsH
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How You Can Call 3GL ProceduresIn t
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How You Can Use Exec 4GL Statements
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How You Can Link 3GL ProceduresHow
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Sample 3GL ProceduresExec 4GL and E
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How You Can Use Data Entry Error Ha
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Chapter 12: Managing Event QueuesTh
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Event-based ProgrammingThe followin
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Event-based ProgrammingEvent TypesT
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Event-based ProgrammingField Events
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Event-based ProgrammingBecause all
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Event-based ProgrammingThe followin
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Event-based ProgrammingThe resume s
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Event-based ProgrammingNote: The da
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Communicating Between OpenROAD Fram
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Page 363 and 364: Chapter 14: Creating Dynamic Frames
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Page 373 and 374: How You Can Create and Modify Field
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Page 383 and 384: How You Can Manipulate Data in Dyna
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Page 418 and 419: Dynamic Statements ConsiderationsDy
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Page 422 and 423: How You Can Write an AssistantFirst
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PreprocessorThe #define StatementTh
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Error ProcessingGuidelines for Usin
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Chapter 18: Debugging Your Applicat
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How You Can Test an ApplicationHow
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How You Can Use Break ConditionsTo
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How You Can Use Break Conditions3.
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How You Can Use Break ConditionsWay
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How You Can Use Break ConditionsSet
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How You Can Use Break Conditions•
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How You Can Use Break ConditionsMet
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How You Can Log Trace InformationDa
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How You Can Monitor a Running Appli
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How You Can Monitor a Running Appli
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How You Can Debug Database QueriesT
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How Debugging an Application WorksS
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How Debugging an Application WorksH
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How Debugging an Application WorksW
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How Debugging an Application WorksH
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How Debugging an Application WorksW
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How Debugging an Application WorksL
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How Debugging an Application WorksA
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Appendix A: SQL Syntax SummaryThis
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SQL Syntax Summarygrant all [privil
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OpenSQL Syntax SummaryOpenSQL Synta
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Operating System CommandsThe follow
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BitmapObject classThe BitmapObject
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external classAn external class def
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local variableLocal variables conta
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StringObject classThe StringObject
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Index'' ' (single quotation marks)c
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Attributesdefined • 28referencing
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using to copy data • 244using wit
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application threads • 444array di
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examining values • 473hexadecimal
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Gmoney • 51numeric list • 53pad
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Namesapplication • 21dynamic •
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ReadOps attributesettings • 243Re
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concat function • 54functions •
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event chains • 323event queue •
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