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ftWideString

ftWideString = 24

Example​

function IsUnicodeString(Field: TField): Boolean;
begin
  Result := Field.DataType = ftWideString;
end;

Usage​

ftWideString identifies variable Unicode character data whose declared Size and database encoding remain provider-level metadata.

Additional Technical Info​

ftWideString is declaration ordinal 24 of TFieldType. It identifies a bounded, variable-length Unicode character field.

The installed RTL maps it to TWideStringField, which descends from TStringField but uses Delphi Unicode strings and wide-character buffers. A new base string field begins with Size = 20; live field definitions override that metadata. Size is not a portable byte limit: database characters, Unicode scalar values, UTF-16 code units and encoded storage bytes can differ.

Use this family when the provider exposes Unicode-capable text. Converting it to ANSI can lose characters. Conversely, the enum does not guarantee that the destination database accepts every Unicode value or preserves normalization, supplementary characters or trailing spaces. Those properties depend on the driver, database character set and collation.

Null remains distinct from ''. Validate length using the destination's definition rather than Delphi's string length alone, and do not assume that local case/ordering rules reproduce database comparisons. Use ftFixedWideChar for fixed-width metadata and ftWideMemo for large Unicode text.

The example only inspects metadata and was source-reviewed; no Unicode, collation, dataset, database, runtime or image test ran.

External references

Created 2026-07-15