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Stored Procedures

Question: What are the common uses of stored procedures? Answer: Many databases use stored procedures and/or triggers to implementreferential integrity [ensuring that data referenced by another tabledoesn’t get deleted or

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Creating Views

Question: I’ve got a “new user” question for you. Some of the tables in our databaseshave several columns containing data that’s not used very often. When I’musing ad-hoc queries, it

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New Features

Question: What are some of the new features of Power Objects Version 2? Answer: The major new features of Version 2.0 include:New platforms – OPO will continue to support both

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Selecting multiple rows

Question: I want to let the user select more than one row in a repeater so my application can act on all of them at one time? Answer: A repeater

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Tables in a session

Question: When I open a session to my Oracle database, I can only see tables that are owned by my user name. How can I get to see other public

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Forms without MDI

Question: I want to have a form that does not appear in a MDI (multiple document interface) frame. Can I do this? Answer: In Version 2 of Power Objects, you

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Dates in String Variables

Question: I want to use a string variable with the date in it (format would be 02/22/96). How do I accomplish this? Answer: You’ll need to first convert the date

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Embedded SQL

Question: What is Embedded SQL, and howis it used with the C language? Answer: As the name implies, Embedded SQL describes SQL statements that are embedded in a host language.

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Simulating Multiple Outer Joins

Question: I need to query a database with outer joins on more thanone table, and am finding that my database doesn’t support it.Is there any way to work around the

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Combining Columns of Different Types

Question: I am doing a select from a table where I want to combine two fields. Specifically, I have the StreetNumber andthe StreetName stored separately. I would like to beable

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Inserting rows

Question: When I insert a row into a table, the results from the query that come after the row don’t show up. If I re-fetch the results, I can get

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Flushing and Locking

Question: How can I set the flushing of rows to the database or the locking strategy used by Power Objects? Answer: Oracle Power Objects ‘supports’ two ways that rows can

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Clearing menu bars

Question: I can’t seem to clear the default menus in a modal dialog box. I have triedall types of code in the OpenModal() method, but the default menusstill appear. How

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Lock failure

Question: I am using the Japanese version of OPO. Occasionally, I get an error messagethat says ‘Failed to lock row.’ It doesn’t happen all the time. What makesOPO lock a

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Structured variables

Question: It seems like I cannot define my own data structures in OPO. I want to create an variable that actually consists of different underlying variables – a string followed

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“Null” method

Question: I want to be able to start a section of code if nothing is happening in an application. This type of ‘null’ method is useful for default tasks. How

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Check box in a repeater

Question: I want to manipulate a check box in a repeater control, but the check box is not bound to any data column. How can I do this? Answer: Every

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Dependent values

Question: I want to create a list box that will contain values based on the value ofanother list box. How can I accomplish this? Answer: A list box is populated

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QBF menu

Question: I am using custom toolbars in my application. When I call the QBF form, ithas a default menu bar. How can I get rid of this? Answer: While the

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DBMS Advantages

Question: Our business is just starting to look at using a relational databasemanagement system. We are currently using computers, but the usershave their own copies of whatever data they need

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User changes

Question: I want to be able to take an action when a user changes the value of a data field, but not when the value of the field is changed

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RDBMS Strengths

Question: What are the major strengths of a RDBMS when compared to anODBMS? Answer: Most ODBMS today are still weak in the area of security, so if you are planning

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ODBMS vs. RDBMS

Question: Under which circumstances should I consider an object database management system (ODBMS) instead of a relational database managementsystem (RDMBS)? Answer: There are some specific types of applications that are

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Client-Server Architecture

Question: I’ve heard a lot of talk about “client-server architecture” ? is it something real, or just marketing hype? Answer: Indeed, client-server architecture is real. Put simply, the client-server model

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OnKey()

Question: What is the OnKey() method? Answer: The OnKey() method is a new method introduced with OPO version 1.0.16. The OnKey() method is triggered for an object whenever a user

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Can’t see tables

Question: When I open a session to an Oracle database, I can’t see any tables other than those owned by my user name. How can I get access to tables

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OLE client

Question: Can an OPO application act as an OLE client and use OLE automation with an OLE server? Answer: OPO Version 2.0 can act as an OLE server, but not

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Compound key

Question: I want to use a unique compound key, with a string columns and a numeric column, in my table. Since Blaze does not support compound keys, I will have

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Repeater fields

Question: Whenever I try to reference an object in a repeater, I get an error message telling me that “Repeated control can be used only in aggregation function”. How can

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Balnk form

Question: How do I open up a blank form – a form without any values displayed? Answer: As you probably know, you can add a DefaultCondition to your form, such