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Returns a tag name from an open compound index (.cdx) file or the name of an open single-entry (.idx) index file.
TAG([CDXFileName[, nTagNumber[, nWorkArea | cTableAlias]]]) |
Parameters
- CDXFileName
- Specifies the name of the .cdx file to return a tag name from.
- nTagNumber
-
Specifies a number corresponding to the order in which a tag was created in the compound index file.
For example, if nTagNumber is 1, TAG(В ) returns the name of the first tag created in the compound index file. If nTagNumber is 2, TAG(В ) returns the name of the second tag created, and so on. TAG(В ) returns the empty string when nTagNumber exceeds the number of tag names.
If you omit CDXFileName, TAG(В ) returns compound index file tag names and single-entry index file names in a specific order as follows:
-
Names of single-entry index files are returned based on their order in the INDEX clause of USE or SET INDEX. For more information, see USE Command and SET INDEX Command.
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Tag names from the structural compound index file (if one exists for the table) are returned.
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Tag names from other open compound index files are returned, again in the order in which the tags were created in the compound index files and in the order in which the compound index files are specified in the INDEX clause for USE or SET INDEX.
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Names of single-entry index files are returned based on their order in the INDEX clause of USE or SET INDEX. For more information, see USE Command and SET INDEX Command.
- nWorkArea| cTableAlias
- Returns tag names and index file names from files open in another work area. nWorkArea specifies a work area number and cTableAlias specifies a table alias. By default, tag names and index file names are returned from files in the current work area.
Return Value
Character. TAG(В ) returns an index tag name as an uppercase character string.
Remarks
Tags are index entries in compound index (.cdx) files created with the INDEX command. Single-entry index (.idx) files contain only one entry; therefore, TAG(В ) returns the file name for .idx files.
 Note: |
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| A structural compound index (.cdx) file opens with its table automatically. You can open non-structural .cdx files and .idx index files for a table using the INDEX clause in the USE command or using the SET INDEX command. |
Example
The following example closes all other open databases and opens the Customer table in the Visual FoxPro sample TestData database located in the directory, ..\Microsoft Visual FoxPro\Samples\Data. The FOR ... ENDFOR command uses the TAGCOUNT(В ) function to create a loop numbering from the first index tag to the total number of index tags in the open structural compound index (.cdx) file. The TAG(В ) and file CDX(В ) functions retrieve the index tags from the file and displays them using the ? command.
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CLOSE DATABASES OPEN DATABASE (HOME(2) + 'Data\TestData') USE Customer CLEAR FOR nCount = 1 TO TAGCOUNT() ? TAG(CDX(1),nCount) ENDFOR | |
For more information, see FORВ ...В ENDFOR Command, TAGCOUNT(В ) Function, CDX(В ) Function, and ? | ?? Command.