Method stringBoolean

src/dsql/BoolNodes.cpp:860–1063

Perform one of the complex string functions CONTAINING, MATCHES, or STARTS WITH.

// Perform one of the complex string functions CONTAINING, MATCHES, or STARTS WITH.
bool ComparativeBoolNode::stringBoolean(thread_db* tdbb, Request* request, dsc* desc1,
	dsc* desc2, bool computedInvariant) const
{
	SET_TDBB(tdbb);

	USHORT type1;

	if (!desc1->isBlob())
		type1 = INTL_TEXT_TYPE(*desc1);
	else
	{
		// No MATCHES support for blob
		if (blrOp == blr_matching)
			return false;

		type1 = desc1->dsc_sub_type == isc_blob_text ? desc1->dsc_blob_ttype() : ttype_none;
	}

	Collation* obj = INTL_texttype_lookup(tdbb, type1);
	CharSet* charset = obj->getCharSet();

	VaryStr<TEMP_STR_LENGTH> escapeTemp;
	const UCHAR* escapeStr = nullptr;
	USHORT escapeLen = 0;

	// Handle escape for LIKE and SIMILAR
	if (blrOp == blr_like || blrOp == blr_similar)
	{
		// ensure 3rd argument (escape char) is in operation text type
		if (arg3 && !computedInvariant)
		{
			// Convert ESCAPE to operation character set
			dsc* desc = EVL_expr(tdbb, request, arg3);

			if (request->req_flags & req_null)
			{
				if (nodFlags & FLAG_INVARIANT)
				{
					impure_value* impure = request->getImpure<impure_value>(impureOffset);
					impure->vlu_flags |= VLU_computed;
					impure->vlu_flags |= VLU_null;
				}
				return false;
			}

			escapeLen = MOV_make_string(tdbb, desc, type1,
				reinterpret_cast<const char**>(&escapeStr), &escapeTemp, sizeof(escapeTemp));

			if (!escapeLen || charset->length(escapeLen, escapeStr, true) != 1)
			{
				// If characters left, or null byte character, return error
				ERR_post(Arg::Gds(isc_escape_invalid));
			}

			USHORT escape[2] = {0, 0};

			charset->getConvToUnicode().convert(escapeLen, escapeStr, sizeof(escape), escape);