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AsSQL

property AsSQL: string read write

Example​

procedure ScriptEvent(var Value: variant);
begin
  { Getter only: use parameters rather than concatenating SQL when available. }
  Value := Field.AsSQL;
end;

Usage​

AsSQL quotes formatted field display text for SQL-shaped output but has a lossy, unvalidated setter that is not its inverse.

Lossy setter defect

The setter calculates:

lValue := Copy(Value, 2, Length(Value) - 3);

It then converts doubled apostrophes to singles and assigns AsString. For the normally quoted input 'abc', Copy returns ab: Velox removes the opening quote plus the closing quote and the final data character. It does not validate that quotes exist. Short/malformed values can become empty or unexpectedly truncated.

The setter is therefore not the inverse of the getter. Avoid it; do not round-trip Field.AsSQL := Field.AsSQL. Assignment also follows the field's edit, conversion and validation behavior and can raise after the truncation has occurred in memory.

The getter allocates replacement strings proportional to display length. Neither accessor posts or commits; the setter changes the current record only.

Additional Technical Info​

The AsSQL getter passes the field's formatted DisplayText to Velox SafeSQL.

SafeSQL performs these text operations in order:

  1. remove every NUL character (#0);
  2. replace every apostrophe with two apostrophes; and
  3. wrap the result in single quotes.

For example, display text O'Brien becomes 'O''Brien'. Database null normally has empty display text and becomes '', not SQL NULL. Numeric, Boolean and date values are also quoted as strings. Because the source is DisplayText, field display formats and OnGetText can change the literal independently of the raw value.

This is product-specific SQL-shaped text, not type-aware serialization or parameter binding. Prefer parameters. Do not use it for identifiers, complete SQL fragments or authorization-sensitive construction.

External references

Created 2026-07-15