------------------------------------------------------------ Visual dBASE 7 README.TXT Updated 11/20/97 5:52 PM Welcome to Visual dBASE 7! This next generation in dBASE development includes many new productivity-enhancing features, including: * Native 32-bit development * 32-bit Visual dBASE Compiler * Integrated native Visual dBASE Report Writer * Visual Project Explorer * Enhanced Visual Designers * Live Two-Way Tools * Powerful Source editor with TreeView control * Programmable Grid control * ActiveX integration * Rich set of new Database components * New DBF 7 Format * Automatic field lookup and fill-in * SQL Designer * New language elements Be sure to check the Contents page of the online Help for more information on these and other new features, a list of changes from previous versions, and information on documentation updates, white papers, and other technical information. ------------------------------------------------------------ CONTENTS ------------------------------------------------------------ 1. GENERAL USAGE NOTES 2. BDE NOTES AND ISSUES 3. NOTES FOR USERS OF EARLIER VERSIONS 4. Visual dBASE RESOURCES 5. UNINSTALLING THE PROGRAM ------------------------------------------------------------ 1. GENERAL USAGE NOTES ------------------------------------------------------------ * For a guide to the sample code and utilities, run the "Sample Guide.wfm" form in the \Samples directory. * When creating a PRIMARY or DISTINCT index on a DBF or DB table, records with duplicate key values are copied to a KEYV??? table and deleted from the original table. * The interactive BROWSE command has no options (contrary to the documentation -- the listed options are ignored). The Browse class does not support the text property as documented in the Help; all other Help-documented properties are supported. All other version 5.x properties are ignored, and are listed in the Obsolete category of the Inspector. * In the fields property of the Browse control, the Read- only, Range, When, Valid, and Error message options do not work. * Automatic field lookup and fill-in is provided by the lookupSQL and lookupRowset properties of the Field object. If these properties are defined as custom field properties in a DBF7 table, the Form wizard will create comboboxes for those fields, which will automatically contain the lookup values. * Do not enclose DBCS (Double Byte Character Set) alias names in quote marks in SQL statements. * The Remote Data Entry and Query And Response Web Wizards currently work with O'Reilly's WebSite 2.0 only. Visit the Visual dBASE home site (see below for URL) for information on using other web servers. ------------------------------------------------------------ 2. BDE NOTES AND ISSUES ------------------------------------------------------------ * The DBASE driver now defaults to Level 7. Tables that are created from scratch (e.g. with CREATE or CREATE TABLE, as opposed to being copied from existing tables) will be DBF7 tables. To change the Level setting, close Visual dBASE (as well as any other programs that may be using the Borland Database Engine) and use the BDE Administrator utility (BDEADMIN.EXE). Change the Level setting in [\Configuration\Drivers\Native\DBASE] to the desired level. Then restart Visual dBASE. * When sharing .DBF tables with a non-BDE application (e.g. Clipper, FoxPro), set the BDE Local Share [\Configuration\System\INIT] setting to true to ensure that record locks are respected between that application and Visual dBASE. The same applies when sharing with a BDE16 application like Visual dBASE 5.x; in addition, the BDE16 configuation must also have its Local Share (in the System tab of the BDE Configuation Utility) set to true. * To create FoxPro tables, create a BDE database alias using the new FoxPro driver in the BDE Administrator and use that alias as the active database. (Do not use the DBASE driver at Level 25, as with earlier versions of BDE.) You do not have to create an alias to use existing FoxPro tables; the BDE automatically distinguishes between dBASE and FoxPro DBFs. * Connecting to a database twice with ODBC 3.4: Due to a known bug in Microsoft's ODBC 3.4, connecting to a database twice with this driver can cause Visual dBASE to shut down. This problem is fixed in ODBC 3.5. * In Local SQL, when querying logical fields do not use single or double quotes around the boolean literal in the criteria. For example, the following SQL statement is the correct syntax: SELECT some_field FROM table WHERE boolean_field = true * When using the AS clause to rename a field, the field name cannot exceed 31 characters, including the table or alias name if used (the dot between the table and field names and quote marks around the names are not counted). For example, the field name in the following SQL statement is 31 characters, the maximum allowed length: SELECT fd AS t23."f567890123456789 12345678901" FROM t23 Note that the SQL designer omits the optional AS keyword. It would generate an SQL statement that looks like: SELECT fd t23."f567890123456789 12345678901" FROM t23 * Perform a parameterized SQL operation on a BLOB field only if the value of the parameter is less than 256 bytes. * If you install the trial version of IntraBuilder or C++Builder (or any other Borland product) after installing Visual dBASE 7, you may overwrite the new version of BDE with an older version. To prevent this, deselect the BDE when installing the older software, or reinstall the BDE from Visual dBASE 7 using the Custom install option. MS Access support: * To enable Access support, the Microsoft DAO/Jet engine must already be installed on the target machine. This component is provided by Microsoft Access/Office and some Microsoft development tools; it is not provided by Visual dBASE. * Some functionality is not yet implemented in the Access driver in this release. BCD (binary coded decimal) support is not available. Key-violation tables cannot be created when creating an index. Heterogeneous queries and queries using the local SQL engine are not supported. In addition, you cannot MODIFY STRUCTURE or REINDEX. * MS Access does not support opening a table that has already been opened exclusively. Hence opening a table exclusively prevents the user from opening that table again, even in same session. DBF Referential Integrity (RI): * With multiple RI tiers (e.g. parent is linked to middle, middle is linked to child), the RI links must be created from the parent toward the child. That is, the parent->middle link must be made before the middle->child link. Modifications must be made in this order as well, otherwise the links may become out-of-sync internally. If it is suspected that the RI links have become out-of- sync, go into the RI dialog and "Modify"/"OK" each RI link starting from the parent link to the child link. * When restructuring tables with referential integrity links (including deleting or modifying indexes), be sure to drop the RI links before making modifications to the tables. Otherwise, the RI links may become out-of-sync internally. If it is suspected that the links have become out-of-sync, please follow the step described in the previous paragraph. * Cascaded deletes are not allowed for multi-tier (more than parent and child) RI links. The user will receive the error message, "Database Engine Error: Conflicting record lock in this session". * Circular RI links are not supported (e.g. master->detail, detail->master) for this version. ------------------------------------------------------------ 3. NOTES FOR USERS OF EARLIER VERSIONS ------------------------------------------------------------ For an overview of new features and functionality, as well as a review of what's changed in Visual dBASE, see VDB.HLP in the \Help directory (or choose Visual dBASE Help from the Start menu) In addition, please note the following: * Visual dBASE will automatically upgrade a .DBF table to the new DBF7 format if you restructure or modify the schema of the table in any way, including with the CONVERT command. (Simply modifying the records of the table does not automatically change the format.) Attempting to USE a DBF7 table in an earlier version of dBASE will cause an error. To prevent this, change the DBASE driver Level setting, as detailed in BDE Notes above, before restructuring the table. * It is no longer necessary to USE a table EXCLUSIVE to MODIFY STRUCTURE. MODIFY STRUCTURE always attempts to reopen the table in exclusive mode. * Although .QBEs are still functional, .DMDs (data modules) are now recommended for defining an updateable set of tables (both linked and unlinked). A .QBE to .DMD converter (QBE2DMD.PRG) is available in the \Utilities\Upgrade directory. This converter can also be run from the Sample Guide form. * Changes in the default design font (from MS Sans Serif 8 to Arial 10) may affect forms you created using earlier versions of Visual dBASE. * Forms and menus are now streamed using the new WITH syntax instead of the old DEFINE syntax. If you want to run the same form/menu in an earlier version of Visual dBASE, keep a separate copy. * The REPORT FORM and LABEL FORM commands are not functional in this release. To run a new native report or label, DO the .REP or .LAB file (just like a form). * With the exception of COLUMNAR, the EDIT command has no options. * The BUTTONS.CC custom control library is not included with this product. The library from earlier versions will not work in Visual dBASE 7 without adjustments to the library's ReportButton and ToolButton classes. Because there is now a built-in ToolButton class (used in toolbars), you must rename the ToolButton class in BUTTONS.CC, and all instances of that class in your existing code. * The include files UTIL.H, ENUM.H, and MESSDLG.H have been replaced by the file VDBASE.H in the \Include subdirectory. Change any #include statements that reference those old files to the new file, or copy the old files from an earlier version of Visual dBASE into the new \Include subdirectory. ------------------------------------------------------------ 4. Visual dBASE RESOURCES ------------------------------------------------------------ The Visual dBASE home site on the World Wide Web, at http://www.borland.com/VdBASE (all URLs are case-sensitive), helps you find the most current information about Visual dBASE. Periodic upates to the Visual dBASE Help system, as well as technical notes, tips, and other materials that will further your understanding of the program, can be found through the Product Library and Developer Support links. Borland offers a number of newsgroups for obtaining and exchanging information on Visual dBASE and other Borland products. To access the newsgroups, set your news reader to point to the server forums.borland.com, or visit http://www.borland.com/newsgroups/ You can also subscribe to the dNEWS newsletter for the latest information on Visual dBASE 7 by filling in a form on our Web site and selecting 'Visual dBASE'. The form is available on Borland Online at: http://www.borland.com/feedback/listserv.html ------------------------------------------------------------ 5. UNINSTALLING THE PROGRAM ------------------------------------------------------------ * Windows 95 or Windows NT 4.0: Use the Add/Remove Programs applet in the Control Panel. * Be sure to close the Control Panel before starting the uninstall process. Otherwise, the BDE Administrator, which is in the Control Panel, will not be removed, preventing the uninstall from removing all components. ------------------------------------------------------------ Copyright © 1997 Borland International, Inc. All rights reserved. All Borland products are trademarks or registered trademarks of Borland International, Inc. Other brand and product names used in this document and other documents and files included in this software package are trademarks or registered trademarks of their respective holders. This software is based in part on the work of the Independent JPEG Group (IJG). The Graphics Interchange Format(c) is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated.