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Deepesh125 merged 3 commits into from
Apr 3, 2026
Merged

Fix FOR XML RAW('') empty element name handling and all-NULL row outp… #4689

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Fix FOR XML RAW('') empty element name handling and all-NULL row outp…
JapleenKaur3 Mar 30, 2026
7c90e0d
rerun
Mar 31, 2026
a0793f1
retry
Apr 2, 2026
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64 changes: 52 additions & 12 deletions contrib/babelfishpg_tsql/src/tsql_for/forxml.c
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Original file line number Diff line number Diff line change
Expand Up @@ -215,7 +215,8 @@ tsql_row_to_xml_raw(StringInfo state, Datum record, const char *element_name, bo
TupleDesc tupdesc;
HeapTupleData tmptup;
HeapTuple tuple;

bool allnull = true;

td = DatumGetHeapTupleHeader(record);

/* Extract rowtype info and find a tupdesc */
Expand All @@ -228,19 +229,34 @@ tsql_row_to_xml_raw(StringInfo state, Datum record, const char *element_name, bo
tmptup.t_data = td;
tuple = &tmptup;

/* Output opening tag */
if (elements)
/*
* Empty element name without ELEMENTS mode is not allowed — attribute-centric
* serialization requires a row tag name.
*/
if (element_name[0] == '\0' && !elements)
{
/* ELEMENTS mode: <row><col>value</col></row> */
if (xsinil)
appendStringInfo(state, "<%s " XML_XMLNS_XSI ">", element_name);
else
appendStringInfo(state, "<%s>", element_name);
ereport(ERROR,
(errcode(ERRCODE_INVALID_XML_PROCESSING_INSTRUCTION),
errmsg("Row tag omission (empty row tag name) cannot be used "
"with attribute-centric FOR XML serialization.")));
}
else

/* Output opening tag (only when element_name is non-empty) */
if (element_name[0] != '\0')
{
/* ATTRIBUTES mode: <row col="value"/> */
appendStringInfo(state, "<%s", element_name);
if (elements)
{
/* ELEMENTS mode: <row><col>value</col></row> */
if (xsinil)
appendStringInfo(state, "<%s " XML_XMLNS_XSI ">", element_name);
else
appendStringInfo(state, "<%s>", element_name);
}
else
{
/* ATTRIBUTES mode: <row col="value"/> */
appendStringInfo(state, "<%s", element_name);
}
}

for (int i = 0; i < tupdesc->natts; i++)
Expand All @@ -265,6 +281,7 @@ tsql_row_to_xml_raw(StringInfo state, Datum record, const char *element_name, bo
/* ELEMENTS mode output */
if (!isnull)
{
allnull = false;
/* Normal element: <col>value</col> */
appendStringInfo(state, "<%s>%s</%s>",
colname,
Expand All @@ -273,6 +290,7 @@ tsql_row_to_xml_raw(StringInfo state, Datum record, const char *element_name, bo
}
else if (xsinil)
{
allnull = false;
/* XSINIL: <col xsi:nil="true"/> */
appendStringInfo(state, "<%s " XML_XSI_NIL "/>", colname);
}
Expand All @@ -292,7 +310,29 @@ tsql_row_to_xml_raw(StringInfo state, Datum record, const char *element_name, bo

/* Output closing tag */
if (elements)
appendStringInfo(state, "</%s>", element_name);
{
if (element_name[0] == '\0')
{
/*
* Empty element name with ELEMENTS: no wrapper tag needed.
* Just output the child elements directly, same as PATH('').
*/
}
else if (allnull)
{
/*
* If all column values are NULL, produce a self-closing element
* like TSQL does: <row/>. Replace the '>' in the already
* appended opening tag with '/' and append '>'.
*/
state->data[state->len - 1] = '/';
appendStringInfoChar(state, '>');
}
else
{
appendStringInfo(state, "</%s>", element_name);
}
}
else
appendStringInfoString(state, "/>");

Expand Down
39 changes: 33 additions & 6 deletions test/JDBC/expected/forxml-raw-elements-before-17_9-or-18_3-vu-verify.out
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Original file line number Diff line number Diff line change
Expand Up @@ -143,7 +143,7 @@ SELECT NULL AS a, NULL AS b FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand All @@ -170,7 +170,7 @@ SELECT NULL AS a, NULL AS b, NULL AS c, NULL AS d FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand Down Expand Up @@ -198,7 +198,7 @@ SELECT NULL AS a, NULL AS b FOR XML RAW, ELEMENTS ABSENT;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand Down Expand Up @@ -510,7 +510,7 @@ SELECT name, salary FROM forxml_raw_elements_t1 FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row><name>John</name><salary>50000</salary></row><row><name>Jane</name><salary>60000</salary></row><row><name>Bob</name></row><row><name>Alice</name><salary>70000</salary></row><row></row>
<row><name>John</name><salary>50000</salary></row><row><name>Jane</name><salary>60000</salary></row><row><name>Bob</name></row><row><name>Alice</name><salary>70000</salary></row><row/>
~~END~~


Expand Down Expand Up @@ -950,7 +950,7 @@ SELECT CAST(NULL AS VARCHAR(10)) AS null_val FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand All @@ -971,7 +971,34 @@ SELECT 1 AS a, 2 AS b FOR XML RAW(''), ELEMENTS;
GO
~~START~~
ntext
<><a>1</a><b>2</b></>
<a>1</a><b>2</b>
~~END~~


-- Empty element name without ELEMENTS (attribute-centric) - should error
SELECT 1 AS a, 2 AS b FOR XML RAW('');
GO
~~START~~
ntext
~~ERROR (Code: 33557097)~~

~~ERROR (Message: Row tag omission (empty row tag name) cannot be used with attribute-centric FOR XML serialization.)~~


-- All NULLs under attribute mode (no ELEMENTS)
SELECT NULL AS a, NULL AS b FOR XML RAW;
GO
~~START~~
ntext
<row/>
~~END~~


-- All NULLs with empty element name and ELEMENTS
SELECT NULL AS a, NULL AS b FOR XML RAW(''), ELEMENTS;
GO
~~START~~
ntext
~~END~~


Expand Down
39 changes: 33 additions & 6 deletions test/JDBC/expected/forxml-raw-elements-vu-verify.out
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -143,7 +143,7 @@ SELECT NULL AS a, NULL AS b FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand All @@ -170,7 +170,7 @@ SELECT NULL AS a, NULL AS b, NULL AS c, NULL AS d FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand Down Expand Up @@ -198,7 +198,7 @@ SELECT NULL AS a, NULL AS b FOR XML RAW, ELEMENTS ABSENT;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand Down Expand Up @@ -510,7 +510,7 @@ SELECT name, salary FROM forxml_raw_elements_t1 FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row><name>John</name><salary>50000</salary></row><row><name>Jane</name><salary>60000</salary></row><row><name>Bob</name></row><row><name>Alice</name><salary>70000</salary></row><row></row>
<row><name>John</name><salary>50000</salary></row><row><name>Jane</name><salary>60000</salary></row><row><name>Bob</name></row><row><name>Alice</name><salary>70000</salary></row><row/>
~~END~~


Expand Down Expand Up @@ -950,7 +950,7 @@ SELECT CAST(NULL AS VARCHAR(10)) AS null_val FOR XML RAW, ELEMENTS;
GO
~~START~~
ntext
<row></row>
<row/>
~~END~~


Expand All @@ -971,7 +971,34 @@ SELECT 1 AS a, 2 AS b FOR XML RAW(''), ELEMENTS;
GO
~~START~~
ntext
<><a>1</a><b>2</b></>
<a>1</a><b>2</b>
~~END~~


-- Empty element name without ELEMENTS (attribute-centric) - should error
SELECT 1 AS a, 2 AS b FOR XML RAW('');
GO
~~START~~
ntext
~~ERROR (Code: 33557097)~~

~~ERROR (Message: Row tag omission (empty row tag name) cannot be used with attribute-centric FOR XML serialization.)~~


-- All NULLs under attribute mode (no ELEMENTS)
SELECT NULL AS a, NULL AS b FOR XML RAW;
GO
~~START~~
ntext
<row/>
~~END~~


-- All NULLs with empty element name and ELEMENTS
SELECT NULL AS a, NULL AS b FOR XML RAW(''), ELEMENTS;
GO
~~START~~
ntext
~~END~~


Expand Down
12 changes: 12 additions & 0 deletions test/JDBC/input/forxml/forxml-raw-elements-before-17_9-or-18_3-vu-verify.sql
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Original file line number Diff line number Diff line change
Expand Up @@ -414,6 +414,18 @@ GO
SELECT 1 AS a, 2 AS b FOR XML RAW(''), ELEMENTS;
GO

-- Empty element name without ELEMENTS (attribute-centric) - should error
SELECT 1 AS a, 2 AS b FOR XML RAW('');
GO

-- All NULLs under attribute mode (no ELEMENTS)
SELECT NULL AS a, NULL AS b FOR XML RAW;
GO

-- All NULLs with empty element name and ELEMENTS
SELECT NULL AS a, NULL AS b FOR XML RAW(''), ELEMENTS;
GO

-- Element name with spaces
SELECT 1 AS a FOR XML RAW('element name'), ELEMENTS;
GO
Expand Down
12 changes: 12 additions & 0 deletions test/JDBC/input/forxml/forxml-raw-elements-vu-verify.sql
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -414,6 +414,18 @@ GO
SELECT 1 AS a, 2 AS b FOR XML RAW(''), ELEMENTS;
GO

-- Empty element name without ELEMENTS (attribute-centric) - should error
SELECT 1 AS a, 2 AS b FOR XML RAW('');
GO

-- All NULLs under attribute mode (no ELEMENTS)
SELECT NULL AS a, NULL AS b FOR XML RAW;
GO

-- All NULLs with empty element name and ELEMENTS
SELECT NULL AS a, NULL AS b FOR XML RAW(''), ELEMENTS;
GO

-- Element name with spaces
SELECT 1 AS a FOR XML RAW('element name'), ELEMENTS;
GO
Expand Down
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