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SQLDateTime

Function SQLDateTime(const ADate: TDateTime): string

Example​

procedure ScriptEvent(var Value: variant);
var
  InputValue: TDateTime;
begin
  InputValue := EncodeDateTime(2026, 7, 19, 14, 30, 45, 125);
  Value := SQLDateTime(InputValue);
  // Usually 2026-07-19 14:30:45.125; the time separator is host-locale dependent.
end;

Usage​

SQLDateTime formats a TDateTime as unquoted millisecond SQL date/time text, including zero as Velox's epoch.

Parameters

NameTypeDescription
ADateTDateTime, constVelox serial date/time. Zero is a valid value and receives no null treatment in this function.

Returns

Unquoted text containing year-month-day, hour, minute, second and three millisecond digits. With the usual : time separator it resembles 2026-07-19 14:30:45.125.

Exact output rules

  • YYYY, MM, DD, HH, NN, SS and ZZZ output padded numeric fields.
  • Hyphens, the space and period are ordinary literal characters in Velox's date/time pattern.
  • The two unquoted : characters are locale time-separator placeholders. They normally emit :, but can emit another system-locale separator.
  • ZZZ is the millisecond field decoded from TDateTime; it does not preserve finer-than-millisecond input or negotiate database column precision.
  • No outer single quotes are included.

Errors

Velox catches no exception. Invalid serial values, locale/runtime failures and allocation errors propagate. Database conversion errors can still occur later when a consumer parses the returned text.

Usage notes

Use SQLDateTime only when an unquoted text representation is explicitly required. For SQL commands, a typed parameter carries both value and null state more reliably than interpolated text.

Additional Technical Info​

SQLDateTime converts a TDateTime to unquoted text using Velox's fixed legacy Microsoft SQL pattern YYYY-MM-DD HH:NN:SS.ZZZ. It is registered as a friendlier script name for the native MSSQLDateTime helper.

Despite its name, the result is only date/time text. It is not a quoted SQL literal, a database parameter, a timezone conversion or a guarantee that a particular server/session will parse the text.

The example is fictional and source-reviewed. It was not executed or sent to a database by the documentation workflow.

Implementation

The SQL-format import registers runtime name SQLDateTime to vxSQLFormat.MSSQLDateTime. That implementation performs one call:

vxFormatDateTime('YYYY-MM-DD HH:NN:SS.ZZZ', ADate)

vxFormatDateTime creates TFormatSettings(LOCALE_SYSTEM_DEFAULT) and delegates to Delphi DateTimeToString. The SQL helper adds no quote, zero branch, range check or exception handling.

Zero and null behavior

ADate = 0 is not null here. Delphi TDateTime(0) represents 1899-12-30 00:00:00, so the usual-locale result is 1899-12-30 00:00:00.000. This deliberately differs from SQLDateTimeString, which returns NULL for the same input.

Edge cases and quirks

  • The function's native name and comment say it is for Microsoft SQL parameter formatting, but returning text is not the same as binding a typed parameter.
  • Because time separators are locale-sensitive, the result is not completely culture-invariant even though all fields are numeric.
  • TDateTime contains no timezone or offset. The output does not state whether fields are UTC, local time or a business-local wall clock.
  • Negative or out-of-normal-range serials follow Delphi date decoding rules and may fail.
  • SQL Server type precision/rounding is not modeled. For example, legacy datetime and datetime2 have different supported precision and ranges.
  • The function does not inspect a connection type, database session language, date format or target column.
  • Concatenating the unquoted result into SQL produces syntax that depends on surrounding SQL and server parsing. Prefer typed query parameters.

Side effects

Reads Windows locale data and allocates a result. It performs no database call and changes no state.

Performance and concurrency

One locale snapshot and one date/time formatting operation per call. No shared mutable Delphi format record is used.

Related entries

External references

The SQL wrapper is Velox-specific. These references document its Delphi formatting terminal:

Created 2026-07-15