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AsSQL

property AsSQL: String read write;

Example​

procedure ScriptEvent(var Value: variant);
var
  Text: TJSONString;
  Item: TJSONValue;
begin
  Text := TJSONString.Create;
  try
    Item := Text;
    Item.AsString := 'O''Brien';
    Value := Item.AsSQL;  // 'O''Brien' with outer quotes and doubled apostrophe.
  finally
    Text.Free;
  end;
end;

Usage​

AsSQL produces a legacy quoted SQL-like text literal but has a lossy setter that is not its inverse.

Additional Technical Info​

The getter calls Velox SafeSQL on the null-aware AsString. SafeSQL removes every NUL character, doubles every apostrophe and wraps the result in apostrophes. Null therefore becomes '', not SQL NULL. Structured values are first compact-serialized, then quoted as text.

This is a legacy literal formatter, not a database parameter, identifier quote, type conversion or dialect negotiation. Removing NUL changes data. Use proper query parameters wherever the database API supports them, and do not infer semantic null from the returned text.

The setter is defective and must not be used as a round-trip decoder. It executes Copy(Value, 2, Length(Value)-3) without checking quotes, thereby discarding the first character and final two characters of a normally quoted input. It then replaces doubled apostrophes with single apostrophes and sends the truncated text directly to the concrete virtual setter. For example, assigning the getter output for 'abc' stores ab, not abc.

Short or unquoted input can become blank or arbitrarily truncated. Type-specific conversion/parsing can then raise after changing null state or destructively replace a container. Errors propagate; no original-value rollback occurs. The getter is linear in input length and allocates replacement Strings; neither access is synchronized.

External references

Created 2026-07-15