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Using Locate
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Locate moves the cursor to the first row matching a specified set of search criteria. In its simplest form, you pass Locate the name of a column to search, a field value to match, and an options flag specifying whether the search is case-insensitive or if it can use partial-key matching. (Partial-key matching is when the criterion string need only be a prefix of the field value.) For example, the following code moves the cursor to the first row in the CustTable where the value in the Company column is "Professional Divers, Ltd.":

Copy Code

    var
      LocateSuccess: Boolean;
      SearchOptions: TLocateOptions;
    begin
      SearchOptions := [loPartialKey];
      LocateSuccess := CustTable.Locate('Company', 'Professional Divers, Ltd.', SearchOptions);
    end;

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    TLocateOptions SearchOptions;
    SearchOptions.Clear();
    SearchOptions << loPartialKey;
    bool LocateSuccess = CustTable->Locate("Company", "Professional Divers, Ltd.",

If Locate finds a match, the first record containing the match becomes the current record. Locate returns True if it finds a matching record, False if it does not. If a search fails, the current record does not change.

The real power of Locate comes into play when you want to search on multiple columns and specify multiple values to search for. Search values are Variants, which means you can specify different data types in your search criteria. To specify multiple columns in a search string, separate individual items in the string with semicolons.

Because search values are Variants, if you pass multiple values, you must either pass a Variant array as an argument (for example, the return values from the Lookup method), or you must construct the Variant array in code using the VarArrayOf function. The following code illustrates a search on multiple columns using multiple search values and partial-key matching:

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    with CustTable do
      Locate('Company;Contact;Phone', VarArrayOf(['Sight Diver','P']), loPartialKey);

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    TLocateOptions Opts;
    Opts.Clear();
    Opts << loPartialKey;
    Variant locvalues[2];
    locvalues[0] = Variant("Sight Diver");
    locvalues[1] = Variant("P");
    CustTable->Locate("Company;Contact", VarArrayOf(locvalues, 1), Opts);

Locate uses the fastest possible method to locate matching records. If the columns to search are indexed and the index is compatible with the search options you specify, Locate uses the index.

See Also

Using Lookup

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