Cumulative season's silent-bug hunting (~62 fixes) across the FiveSql2 SQL engine, the Five compiler/runtime, and the hbrdd RDD layer. Saved as a single checkpoint before refactoring the parser to delegate xBase command translation to the preprocessor. Highlights: FiveSql2 engine (_FiveSql2/src/) - prefix-glob index attach -> explicit convention (<table>_pk.ntx, <table>_uq.ntx, <table>.cdx) — fixes silent multi-row INSERT row-drop - DROP/CREATE TABLE FErase chain extended (.cdx, .fsc, .fsv, .dbt, .fpt) - COUNT(DISTINCT col) parsed + aggregated via hSeen hash - UNION column-count mismatch returns SQL_ERR_GRAMMAR (was silent) - DISTINCT + ORDER BY hidden-col leak fixed (trim before DISTINCT) - Derived table FROM (SELECT...) + JOIN right-side derived - Self-FK CASCADE depth 2+ via SqlGetSingleColPK pre-collect - LAG/LEAD default arg uses SqlEvalRowExpr (handles -N const exprs) - DATE literal round-trip validation (Feb 29 non-leap rejected) - CREATE OR REPLACE VIEW; CREATE VIEW errors on already-exists - AlterTable type dispatcher comma-wrapped (1-char type "A" no longer matches CHARACTER) Compiler / runtime - gengo: HB_ -> FV_ prefix on emitted Go function names (Five identity) - gengo split: emit_block.go, emit_stmt.go, folding.go extracted - parser/stmtreg.go nudges - hbrt: debug TUI/CLI restructure (debugcmd, debugkey, termios_*), windows debug stubs collapsed - thread/vm/value/class/pcinterp tightening from panic traces RDD layer (hbrdd/) - dbf: null bitmap support (null.go + null_test.go), mmap split (mmap_posix.go / mmap_windows.go), byte-level numeric parse - ntx/cdx: windows mmap parity - workarea + mem RDD: cross-area state-bleed fixes RTL (hbrtl/) - errorlog rewrite with platform-specific FD (errorlog_fd_unix / errorlog_fd_other) - sqlscan, sqlhelpers, indexrtl, datetime extensions Gates green at checkpoint: - go test ./... : PASS - FiveSql2 SQL:1999 : 43/43 - Harbour compat : 56/56 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
FiveSql2 — SQL Engine for Harbour DBF/NTX/CDX
Pratt parser + SQL:1992-2023 full standard support Supports both NTX (Clipper) and CDX (FoxPro/ADS) indexes
Architecture
five_SQL("SELECT ...")
│
├── TSqlLexer Tokenizer
├── TSqlParser2 Pratt parser (data-driven operators)
├── TSqlExecutor Query executor (Volcano model)
│ ├── TSqlAlias Central alias manager (no collisions)
│ ├── TSqlIndex NTX/CDX index optimization (auto-detect)
│ ├── TSqlAgg GROUP BY / aggregation
│ ├── TSqlSort ORDER BY / DISTINCT
│ ├── TSqlDDL CREATE/DROP/ALTER TABLE/INDEX
│ └── TSqlTxn BEGIN/COMMIT/ROLLBACK
├── TSqlExpr AST nodes + expression evaluation
└── TSqlFunc 60+ scalar functions
Build & Test
export PATH="/path/to/harbour-core/bin/linux/gcc:$PATH"
export HB_INSTALL_PREFIX="/path/to/harbour-core"
make # Build all tests
make test # Run all 157 tests
make bench # Parser benchmark
make clean # Clean
SQL Standard Coverage
| Standard | Features | Tests |
|---|---|---|
| SQL:1992 | SELECT, JOIN, GROUP BY, HAVING, Subquery, CASE, CAST | 43 |
| SQL:1999 | CTE, Recursive CTE, Window Functions, MERGE | 10 |
| SQL:2003 | SIMILAR TO, GROUPING SETS, LATERAL, Window frames | 64 |
| SQL:2008 | FETCH/OFFSET, FOR UPDATE, Extended MERGE | (incl.) |
| SQL:2016 | JSON functions, LISTAGG | (incl.) |
| SQL:2023 | ANY_VALUE, GREATEST/LEAST, BOOL_AND/OR | (incl.) |
| Challenge | LeetCode-level complex queries | 15 |
| Extreme | Production analytics stress tests | 15 |
Adding New Operators
Edit TSqlParser2.prg, method InitInfixTables():
::hInfixTT[ TK_MYOP ] := { "<=>", 40, 41, ND_BIN }
One line. No structural changes needed.
Copyright
Copyright (c) 2025-2026 Charles KWON (Charles KWON OhJun) Email: charleskwonohjun@gmail.com All rights reserved.