SQL Server (T-SQL) Keyword Compatibility Reference

Generated for GSP Java version 4.1.0.8 on 2026-03-15

This page was generated using hybrid static extraction from parser source files combined with runtime validation against the actual GSP parser. Re-run the extraction script after parser updates to keep this page current.

Keyword-as-Column-Name Support

As of version 4.1.0.8, the GSP SQL Server parser includes a lexer lookahead mechanism that allows 5 vendor-unreserved keywords to be used as unquoted column names in SELECT statements.

The lookahead pre-scans the token list before parsing and converts context-specific keywords to identifiers when they appear in column-name position:

• After: SELECT, ,, DISTINCT, or ALL
• Before: FROM, AS, WHERE, GROUP, ORDER, HAVING, LIMIT, UNION, INTERSECT, EXCEPT, INTO, ,, ), or ;

-- Works: keyword as column name
SELECT case FROM t;

-- Works: keyword as column name
SELECT next FROM t;

-- Works: keyword as column name
SELECT parse FROM t;

-- Original keyword syntax also still works

---

Full Classification Overview

Out of 586 keywords recognized by the GSP SQL Server parser:

Classification	Count	Description
Allowed	537	Can be used as an unquoted column name in both canonical contexts
Context-specific	7	Fails as SELECT keyword FROM t but works as SELECT t.keyword FROM t
Blocked	42	Cannot be used as an unquoted column name in either context

Context-Specific Keywords (7)

These keywords fail when used as bare column names (SELECT keyword FROM t) but succeed when table-qualified (SELECT t.keyword FROM t).

Keyword	Reason
ALL	SELECT qualifier
CASE	Expression keyword
DISTINCT	SELECT qualifier
NEXT	Grammar keyword
PARSE	Grammar keyword
TOP	SELECT qualifier
UNION	Clause keyword

Blocked Keywords (42)

These keywords cannot be used as unquoted column names in either context.

Keyword	Workaround
BREAK	SELECT "break" FROM t
CHECKPOINT	SELECT "checkpoint" FROM t
CLOSE	SELECT "close" FROM t
COMMIT	SELECT "commit" FROM t
CONTINUE	SELECT "continue" FROM t
DBCC	SELECT "dbcc" FROM t
DEALLOCATE	SELECT "deallocate" FROM t
DECLARE	SELECT "declare" FROM t
DELETE	SELECT "delete" FROM t
DENY	SELECT "deny" FROM t
EXEC	SELECT "exec" FROM t
EXECUTE	SELECT "execute" FROM t
FETCH	SELECT "fetch" FROM t
FROM	SELECT "from" FROM t
GOTO	SELECT "goto" FROM t
GRANT	SELECT "grant" FROM t
IF	SELECT "if" FROM t
INSERT	SELECT "insert" FROM t
KILL	SELECT "kill" FROM t
MERGE	SELECT "merge" FROM t
OPEN	SELECT "open" FROM t
PRINT	SELECT "print" FROM t
RAISERROR	SELECT "raiserror" FROM t
READTEXT	SELECT "readtext" FROM t
RECONFIGURE	SELECT "reconfigure" FROM t
RETURN	SELECT "return" FROM t
REVERT	SELECT "revert" FROM t
REVOKE	SELECT "revoke" FROM t
ROLLBACK	SELECT "rollback" FROM t
SAVE	SELECT "save" FROM t
SELECT	SELECT "select" FROM t
SET	SELECT "set" FROM t
SETUSER	SELECT "setuser" FROM t
SHUTDOWN	SELECT "shutdown" FROM t
THROW	SELECT "throw" FROM t
UPDATE	SELECT "update" FROM t
UPDATETEXT	SELECT "updatetext" FROM t
USE	SELECT "use" FROM t
WAITFOR	SELECT "waitfor" FROM t
WHERE	SELECT "where" FROM t
WHILE	SELECT "while" FROM t
WRITETEXT	SELECT "writetext" FROM t

Workaround: Double-Quoted Identifiers

For any keyword that fails as an unquoted column name, you can use double-quoted identifiers:

-- Blocked or context-specific keyword as column name
SELECT "break" FROM t;

-- Or use table qualification for context-specific keywords
SELECT t.all FROM t;

Scope and Limitations

• Tested contexts: SELECT keyword FROM t and SELECT t.keyword FROM t. Other contexts (DDL column definitions, INSERT column lists, aliases) may behave differently.
• Version-specific: This report reflects GSP Java version 4.1.0.8.
• Case sensitivity: Keywords are case-insensitive. select, SELECT, and Select are all treated the same.

How to Report Discrepancies

If you encounter a keyword that behaves differently from what this page describes, please report it through your support channel. Include:

1. The exact SQL statement
2. The GSP parser version
3. Whether the same SQL works in SQL Server

Methodology

1. Static extraction: A Python script parses the lexer (.cod) and grammar (.y) source files to identify all 586 keywords and their grammar classifications.
2. Runtime validation: A Java test harness validates every classification against actual TGSqlParser runtime behavior.
3. JSON dataset: The authoritative data is stored in docs/generated/mssql_keyword_compatibility.json.