gudusoft.gsqlparser.parser

Class ImpalaSqlParser

Object

gudusoft.gsqlparser.parser.AbstractSqlParser

gudusoft.gsqlparser.parser.ImpalaSqlParser

All Implemented Interfaces:

SqlParser

public class ImpalaSqlParser
extends AbstractSqlParser

Apache Impala SQL parser implementation.

This parser handles Impala-specific SQL syntax including:

• Hive-compatible SQL dialect
• Backtick-quoted identifiers (`schema.table`)
• Semicolon statement delimiters
• Impala-specific functions and syntax

Design Notes:

• Extends AbstractSqlParser using the template method pattern
• Uses TLexerImpala for tokenization
• Uses TParserImpala for parsing
• Shares tokenization logic with Hive (dohivetexttotokenlist)
• Delimiter character: ';' for SQL statements

Usage Example:

 // Get Impala parser from factory
 SqlParser parser = SqlParserFactory.get(EDbVendor.dbvimpala);

 // Build context
 ParserContext context = new ParserContext.Builder(EDbVendor.dbvimpala)
     .sqlText("SELECT * FROM employees WHERE dept_id = 10")
     .build();

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

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

Since:

3.2.0.0

See Also:

SqlParser, AbstractSqlParser, TLexerImpala, TParserImpala

Nested Class Summary

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

AbstractSqlParser.PreparedSqlReader

Field Summary

Fields

Modifier and Type	Field and Description
TLexerImpala	flexer The Impala 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
ImpalaSqlParser() Construct Apache Impala SQL parser.

Method Summary

Modifier and Type	Method and Description
protected void	extractVendorRawStatements(SqlParseResult.Builder builder) Call Impala-specific raw statement extraction logic.
protected TCustomLexer	getLexer(ParserContext context) Return the Impala lexer instance.
protected TCustomParser	getParser(ParserContext context, TSourceTokenList tokens) Return the Impala SQL parser instance with updated token list.
protected void	performInterpreter(ParserContext context, TStatementList statements) Perform interpretation/evaluation on parsed statements.
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 Impala-specific semantic analysis using TSQLResolver.
protected void	setupVendorParsersForExtraction() Setup Impala parser for raw statement extraction.
protected void	tokenizeVendorSql() Call Impala-specific tokenization logic.
String	toString()

Methods inherited from class gudusoft.gsqlparser.parser.AbstractSqlParser

afterStatementParsed, attemptErrorRecovery, copyErrorsFromStatement, doAfterTokenize, doExtractRawStatements, extractRawStatements, getanewsourcetoken, getDefaultDelimiterStr, getDelimiterChar, getErrorCount, getrawsqlstatements, getSecondaryParser, 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 TLexerImpala flexer

The Impala lexer used for tokenization

Constructor Detail

ImpalaSqlParser

public ImpalaSqlParser()

Construct Apache Impala SQL parser.

Configures the parser for Impala database with default delimiter (;).

Following the original TGSqlParser pattern, the lexer and parser are created once in the constructor and reused for all parsing operations.

Method Detail

getLexer

protected TCustomLexer getLexer(ParserContext context)

Return the Impala lexer instance.

Specified by:

getLexer in class AbstractSqlParser

Parameters:

context - the parser context

Returns:

configured lexer instance (never null)

getParser

protected TCustomParser getParser(ParserContext context,
                                  TSourceTokenList tokens)

Return the Impala SQL parser instance with updated token list.

Specified by:

getParser in class AbstractSqlParser

Parameters:

context - the parser context

tokens - the source token list

Returns:

configured parser instance (never null)

tokenizeVendorSql

protected void tokenizeVendorSql()

Call Impala-specific tokenization logic.

Delegates to doimpalatexttotokenlist which internally calls dohivetexttotokenlist. Impala shares the same tokenization logic as Hive.

Specified by:

tokenizeVendorSql in class AbstractSqlParser

setupVendorParsersForExtraction

protected void setupVendorParsersForExtraction()

Setup Impala parser for raw statement extraction.

Impala uses a single parser, so we inject sqlcmds and update the token list for the main parser only.

Specified by:

setupVendorParsersForExtraction in class AbstractSqlParser

extractVendorRawStatements

protected void extractVendorRawStatements(SqlParseResult.Builder builder)

Call Impala-specific raw statement extraction logic.

Delegates to doimpalagetrawsqlstatements which internally calls dohivegetrawsqlstatements. Impala shares the same statement extraction logic as Hive.

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.

Specified by:

performParsing in class AbstractSqlParser

Parameters:

context - the parser context

parser - the main parser instance

secondaryParser - secondary parser (may be null)

tokens - the source token list

rawStatements - raw statements already extracted (never null)

Returns:

statement list with parsed AST (never null)

performSemanticAnalysis

protected void performSemanticAnalysis(ParserContext context,
                                       TStatementList statements)

Perform Impala-specific semantic analysis using TSQLResolver.

Overrides:

performSemanticAnalysis in class AbstractSqlParser

Parameters:

context - the parser context

statements - the parsed statements (mutable)

performInterpreter

protected void performInterpreter(ParserContext context,
                                  TStatementList statements)

Perform interpretation/evaluation on parsed statements.

Overrides:

performInterpreter in class AbstractSqlParser

Parameters:

context - the parser context

statements - the parsed statements (mutable)

toString

public String toString()

Overrides:

toString in class AbstractSqlParser