gudusoft.gsqlparser.parser

Class DamengSqlParser

Object

gudusoft.gsqlparser.parser.AbstractSqlParser

gudusoft.gsqlparser.parser.DamengSqlParser

All Implemented Interfaces:

SqlParser

public class DamengSqlParser
extends AbstractSqlParser

Dameng database SQL parser implementation.

This parser handles Dameng-specific SQL syntax including:

• PL/SQL blocks (procedures, functions, packages, triggers)
• SQL*Plus commands (spool, set, show, etc.)
• Dameng-specific DML/DDL (MERGE, flashback, etc.)
• Dameng analytical functions and extensions
• Special token handling (INNER, NOT DEFERRABLE, etc.)

Implementation Status: PHASE 3 - IN PROGRESS

• Completed: Dameng classes (TLexerDameng, TParserDameng, TParserDameng) are now PUBLIC
• Current: Skeleton implementation delegates to legacy TGSqlParser
• Next: Extract vendor-specific logic from TGSqlParser into this class
• Goal: Fully self-contained Dameng parser using AbstractSqlParser template

Design Notes:

• Implements SqlParser directly (will extend AbstractSqlParser in Phase 4)
• Can now directly instantiate: TLexerDameng, TParserDameng, TParserDameng
• Uses two parsers: TParserDameng (SQL) + TParserDameng (PL/SQL blocks)
• Handles SQL*Plus commands via special tokenization logic
• Delimiter character: '/' for PL/SQL blocks, ';' for SQL statements

Usage Example:

 // Get Dameng parser from factory
 SqlParser parser = SqlParserFactory.get(EDbVendor.dbvdameng);

 // Build context
 ParserContext context = new ParserContext.Builder(EDbVendor.dbvdameng)
     .sqlText("SELECT * FROM emp WHERE deptno = 10")
     .build();

 // Parse
 SqlParseResult result = parser.parse(context);

 // Access statements
 TStatementList statements = result.getSqlStatements();
 

Phase 3 Extraction Roadmap:

1. ✅ DONE: Make TLexerDameng, TParserDameng, TParserDameng public
2. ⏳ TODO: Extract tokenization logic (~367 lines from TGSqlParser.dodamengsqltexttotokenlist())
3. ⏳ TODO: Extract raw statement logic (~200 lines from TGSqlParser.dodamenggetrawsqlstatements())
4. ⏳ TODO: Extract parsing orchestration (SQL vs PL/SQL parser selection)
5. ⏳ TODO: Extract helper methods (getanewsourcetoken, getprevsolidtoken, etc.)
6. ⏳ TODO: Extend AbstractSqlParser and use template method pattern fully
7. ⏳ TODO: Remove all delegation to TGSqlParser

Key Methods to Extract from TGSqlParser:

• dodamengsqltexttotokenlist() - Dameng tokenization with SQL*Plus command detection
• dodamenggetrawsqlstatements() - Dameng raw statement boundaries (handles PL/SQL blocks)
• getanewsourcetoken() - Token iterator from lexer
• getprevsolidtoken() - Navigate token list backwards
• IsValidPlaceForDivToSqlplusCmd() - Slash vs divide operator disambiguation
• countLines() - Multi-line token handling
• spaceAtTheEndOfReturnToken() - SQL*Plus command validation

Since:

3.2.0.0

See Also:

SqlParser, AbstractSqlParser, TLexerDameng, TParserDameng, TParserDameng

Nested Class Summary

Nested classes/interfaces inherited from class gudusoft.gsqlparser.parser.AbstractSqlParser

AbstractSqlParser.PreparedSqlReader

Field Summary

Fields

Modifier and Type	Field and Description
TLexerDameng	flexer The Dameng lexer used for tokenization

Fields inherited from class gudusoft.gsqlparser.parser.AbstractSqlParser

defaultDelimiterStr, delimiterChar, frameStack, globalContext, globalFrame, lexer, parserContext, sourcetokenlist, sqlcmds, sqlEnv, sqlstatements, syntaxErrors, vendor

Constructor Summary

Constructors

Constructor and Description
DamengSqlParser() Construct Dameng SQL parser.

Method Summary

Modifier and Type	Method and Description
protected void	afterStatementParsed(TCustomSqlStatement stmt) Override to provide Dameng-specific post-processing after statement parsing.
protected void	doAfterTokenize(TSourceTokenList tokens) Post-tokenization: merge ${...} template variable tokens into single IDENT tokens.
protected void	extractVendorRawStatements(SqlParseResult.Builder builder) Call Dameng-specific raw statement extraction logic.
protected TCustomLexer	getLexer(ParserContext context) Return the Dameng lexer instance.
protected TCustomParser	getParser(ParserContext context, TSourceTokenList tokens) Return the Dameng SQL parser instance with updated token list.
protected TCustomParser	getSecondaryParser(ParserContext context, TSourceTokenList tokens) Return the Dameng PL/SQL parser instance with updated token list.
protected void	performInterpreter(ParserContext context, TStatementList statements) Perform Dameng-specific AST interpretation/evaluation using TASTEvaluator.
protected TStatementList	performParsing(ParserContext context, TCustomParser parser, TCustomParser secondaryParser, TSourceTokenList tokens, TStatementList rawStatements) Perform full parsing of statements with syntax checking.
protected void	performSemanticAnalysis(ParserContext context, TStatementList statements) Perform Dameng-specific semantic analysis using TSQLResolver.
protected void	setupVendorParsersForExtraction() Setup Dameng parsers for raw statement extraction.
protected void	tokenizeVendorSql() Call Dameng-specific tokenization logic.
String	toString() Copy syntax errors from a statement to our error list.

Methods inherited from class gudusoft.gsqlparser.parser.AbstractSqlParser

attemptErrorRecovery, copyErrorsFromStatement, doExtractRawStatements, extractRawStatements, getanewsourcetoken, getDefaultDelimiterStr, getDelimiterChar, getErrorCount, getrawsqlstatements, getSyntaxErrors, getVendor, handleStatementParsingException, initializeGlobalContext, isDollarFunctionDelimiter, onRawStatementComplete, onRawStatementCompleteVendorSpecific, parse, performTokenization, prepareSqlReader, processTokensBeforeParse, processTokensInTokenTable, setTokenHandle, tokenize, towinlinebreak

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

flexer

public TLexerDameng flexer

The Dameng lexer used for tokenization

Constructor Detail

DamengSqlParser

public DamengSqlParser()

Construct Dameng SQL parser.

Configures the parser for Dameng database with default delimiters:

• SQL statements: semicolon (;)
• PL/SQL blocks: forward slash (/)

Following the original TGSqlParser pattern, the lexer and parsers are created once in the constructor and reused for all parsing operations. This avoids unnecessary object allocation overhead since the parser is not thread-safe and designed for single-use per instance.

Method Detail

getLexer

protected TCustomLexer getLexer(ParserContext context)

Return the Dameng lexer instance.

The lexer is created once in the constructor and reused for all parsing operations. This method simply returns the existing instance, matching the original TGSqlParser pattern where the lexer is created once and reset before each use.

Specified by:

getLexer in class AbstractSqlParser

Parameters:

context - parser context (not used, lexer already created)

Returns:

the Dameng lexer instance created in constructor

getParser

protected TCustomParser getParser(ParserContext context,
                                  TSourceTokenList tokens)

Return the Dameng SQL parser instance with updated token list.

The parser is created once in the constructor and reused for all parsing operations. This method updates the token list and returns the existing instance, matching the original TGSqlParser pattern.

Specified by:

getParser in class AbstractSqlParser

Parameters:

context - parser context (not used, parser already created)

tokens - source token list to parse

Returns:

the Dameng SQL parser instance created in constructor

getSecondaryParser

protected TCustomParser getSecondaryParser(ParserContext context,
                                           TSourceTokenList tokens)

Return the Dameng PL/SQL parser instance with updated token list.

Dameng needs a secondary parser (TParserDameng) for PL/SQL blocks (procedures, functions, packages, triggers, anonymous blocks).

The parser is created once in the constructor and reused for all parsing operations. This method updates the token list and returns the existing instance, matching the original TGSqlParser pattern.

Overrides:

getSecondaryParser in class AbstractSqlParser

Parameters:

context - parser context (not used, parser already created)

tokens - source token list to parse

Returns:

the Dameng PL/SQL parser instance created in constructor

tokenizeVendorSql

protected void tokenizeVendorSql()

Call Dameng-specific tokenization logic.

Delegates to dodamengsqltexttotokenlist which handles Dameng's specific keyword recognition, SQL*Plus commands, forward slash disambiguation, and token generation.

Specified by:

tokenizeVendorSql in class AbstractSqlParser

doAfterTokenize

protected void doAfterTokenize(TSourceTokenList tokens)

Post-tokenization: merge ${...} template variable tokens into single IDENT tokens. Template syntax like ${if(len(X) == 0, "", "...")} is used by BI tools.

Overrides:

doAfterTokenize in class AbstractSqlParser

Parameters:

tokens - the source token list (mutable)

setupVendorParsersForExtraction

protected void setupVendorParsersForExtraction()

Setup Dameng parsers for raw statement extraction.

Dameng uses dual parsers (SQL + PL/SQL), so we inject sqlcmds and update token lists for both parsers.

Specified by:

setupVendorParsersForExtraction in class AbstractSqlParser

extractVendorRawStatements

protected void extractVendorRawStatements(SqlParseResult.Builder builder)

Call Dameng-specific raw statement extraction logic.

Delegates to dodamenggetrawsqlstatements which handles Dameng's statement delimiters (semicolon and forward slash).

Specified by:

extractVendorRawStatements in class AbstractSqlParser

Parameters:

builder - the result builder to populate with raw statements

performParsing

protected TStatementList performParsing(ParserContext context,
                                        TCustomParser parser,
                                        TCustomParser secondaryParser,
                                        TSourceTokenList tokens,
                                        TStatementList rawStatements)

Perform full parsing of statements with syntax checking.

This method orchestrates the parsing of all statements by:

• Using the raw statements passed from AbstractSqlParser.parse()
• Initializing SQL and PL/SQL parsers
• Creating global context and frame stack
• Looping through each raw statement
• Calling parsestatement() on each to build AST
• Handling error recovery for CREATE TABLE/INDEX
• Collecting syntax errors

Important: This method does NOT extract raw statements - they are passed in as a parameter already extracted by AbstractSqlParser.extractRawStatements(gudusoft.gsqlparser.parser.ParserContext, gudusoft.gsqlparser.TSourceTokenList, gudusoft.gsqlparser.TCustomLexer, long). This eliminates duplicate extraction that was occurring in the old design.

Extracted from: TGSqlParser.doparse() lines 16903-17026

Specified by:

performParsing in class AbstractSqlParser

Parameters:

context - parser context

parser - main SQL parser (TParserDameng)

secondaryParser - PL/SQL parser (TParserDameng)

tokens - source token list

rawStatements - raw statements already extracted (never null)

Returns:

list of fully parsed statements with AST built

afterStatementParsed

protected void afterStatementParsed(TCustomSqlStatement stmt)

Override to provide Dameng-specific post-processing after statement parsing.

For Dameng, we check if the statement is PL/SQL and recursively find syntax errors in nested PL/SQL statements.

Overrides:

afterStatementParsed in class AbstractSqlParser

Parameters:

stmt - the statement that was just parsed

performSemanticAnalysis

protected void performSemanticAnalysis(ParserContext context,
                                       TStatementList statements)

Perform Dameng-specific semantic analysis using TSQLResolver.

This includes:

• Column-to-table resolution
• Dataflow analysis
• Reference resolution
• Scope resolution

Overrides:

performSemanticAnalysis in class AbstractSqlParser

Parameters:

context - the parser context

statements - the parsed statements

performInterpreter

protected void performInterpreter(ParserContext context,
                                  TStatementList statements)

Perform Dameng-specific AST interpretation/evaluation using TASTEvaluator.

This executes simple SQL statements and evaluates expressions for static analysis and constant folding.

Overrides:

performInterpreter in class AbstractSqlParser

Parameters:

context - the parser context

statements - the parsed statements

toString

public String toString()

Copy syntax errors from a statement to our error list. Extracted from TGSqlParser.copyerrormsg().

Overrides:

toString in class AbstractSqlParser