PRB: INDEX ON with Variable Length Tag May Behave DifferentlyLast reviewed: July 3, 1997Article ID: Q165068 |
The information in this article applies to:
SYMPTOMSWhen attempting to create a variable length index tag in Visual FoxPro version 5.0, one of the following error messages may occur:
Cannot access characters beyond string-or-
Invalid key lengthThis behavior does not occur in earlier versions of FoxPro. According to the Visual FoxPro online Help, variable length index keys are not supported in Visual FoxPro. As stated in the Help file:
If you attempt to build an index with a key that varies in length, the key will be padded with spaces. Variable-length index keys aren't supported in Visual FoxPro.In the case of Visual FoxPro 5.0, it appears that any variable length key is not being padded.
RESOLUTIONThe following code creates an index tag from a variable length key but is padded to a specific length:
SET TALK OFF && If TALK isn't turned off, an error will occur. SET SAFETY OFF CREATE TABLE oneproduct ; (PRODUCT c(15)) SET SAFETY ON INSERT INTO oneproduct (PRODUCT) VALUES ("01PAN AG-1310") INDEX ON PADR(SUBSTR(product, AT(" ", product)+1), ; LEN(product)+2 ," ") TAG prod STATUSMicrosoft is researching this behavior and will post new information here in the Microsoft Knowledge Base as it becomes available.
MORE INFORMATION
Steps to Reproduce BehaviorThe following code illustrates the problem with creating a variable length index tag:
SET SAFETY OFF CREATE TABLE oneproduct ; (PRODUCT c(15)) SET SAFETY ON INSERT INTO oneproduct (PRODUCT) VALUES ("01PAN AG-1310") * The following code works without error in versions prior to 5.0 INDEX ON SUBSTR(PRODUCT,AT(" ",PRODUCT)+1) TAG prod1 INDEX ON RIGHT(PRODUCT,LEN(PRODUCT)-AT(" ",PRODUCT)) TAG prod2 * The following code works without error: *!* SET TALK OFF *!* INDEX ON PADR(SUBSTR(product, AT(" ", product)+1), ; *!* LEN(product)+2 ," ") TAG prodThe first INDEX ON line causes the error message,
Cannot access characters beyond string.The second INDEX ON line causes the error message,
Invalid key length.This behavior does not occur in earlier versions of FoxPro and the indexes are created without error.
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