SampleValues()
Summary
Samples the values of the specified field and returns the specified number of unique values.
Syntax
vals = SampleValues(string field_spec, integer num_unique, integer num_scanned, array options)
| Argument | Contents |
|---|---|
| field_spec | A field spec |
| num_unique | Number of unique values to return |
| num_scanned | Maximum number of records to scan; 1000 is used if num_scanned is greater than 1000 |
No options are currently supported.
Returns
An array of unique values.
Notes
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The records are read in natural order.
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The returned array will be shorter than num_unique if not enough unique values are found in the first num_scanned records.
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If a missing value is encountered among the scanned records, a null will be the first element of the returned array. Other elements in the returned array are in increasing order of occurrence.
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SampleValues() displays a progress bar when scanning 500 or more records. To add a Cancel button to the progress bar, precede the function call with an "on escape" clause. For more information, see Error Handling.
Example
Vals = SampleValues("Population", 20, 200,)Error Codes
| Error Type | Meaning |
|---|---|
| Error | The input field specification is ambiguous |
| Escape | The user clicked Cancel |
| NotFound | The input field does not exist |
See Also
| Function | Summary |
|---|---|
| GetFieldValues() | Reads the values of one or more fields in any number of views |
| GetRecordValues() | Reads the values of one or more fields for a record in a view |