hql-sql.g

hibernate 开源框架的代码 jar包希望大家能喜欢

header
{
// $Id: hql-sql.g 10001 2006-06-08 21:08:04Z [e-mail] $
package org.hibernate.hql.antlr;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
}

/**
 * Hibernate Query Language to SQL Tree Transform.<br>
 * This is a tree grammar that transforms an HQL AST into a intermediate SQL AST
 * with bindings to Hibernate interfaces (Queryable, etc.).  The Hibernate specific methods
 * are all implemented in the HqlSqlWalker subclass, allowing the ANTLR-generated class
 * to have only the minimum dependencies on the Hibernate code base.   This will also allow
 * the sub-class to be easily edited using an IDE (most IDE's don't support ANTLR).
 * <br>
 * <i>NOTE:</i> The java class is generated from hql-sql.g by ANTLR.
 * <i>DO NOT EDIT THE GENERATED JAVA SOURCE CODE.</i>
 * @author Joshua Davis ([e-mail])
 */
class HqlSqlBaseWalker extends TreeParser;

options
{
	// Note: importVocab and exportVocab cause ANTLR to share the token type numbers between the
	// two grammars.  This means that the token type constants from the source tree are the same
	// as those in the target tree.  If this is not the case, tree translation can result in
	// token types from the *source* tree being present in the target tree.
	importVocab=Hql;        // import definitions from "Hql"
	exportVocab=HqlSql;     // Call the resulting definitions "HqlSql"
	buildAST=true;
}

tokens
{
	FROM_FRAGMENT;	// A fragment of SQL that represents a table reference in a FROM clause.
	IMPLIED_FROM;	// An implied FROM element.
	JOIN_FRAGMENT;	// A JOIN fragment.
	SELECT_CLAUSE;
	LEFT_OUTER;
	RIGHT_OUTER;
	ALIAS_REF;      // An IDENT that is a reference to an entity via it's alias.
	PROPERTY_REF;   // A DOT that is a reference to a property in an entity.
	SQL_TOKEN;      // A chunk of SQL that is 'rendered' already.
	SELECT_COLUMNS; // A chunk of SQL representing a bunch of select columns.
	SELECT_EXPR;    // A select expression, generated from a FROM element.
	THETA_JOINS;	// Root of theta join condition subtree.
	FILTERS;		// Root of the filters condition subtree.
	METHOD_NAME;    // An IDENT that is a method name.
	NAMED_PARAM;    // A named parameter (:foo).
	BOGUS;          // Used for error state detection, etc.
}

// -- Declarations --
{
	private static Logger log = LoggerFactory.getLogger( HqlSqlBaseWalker.class );

	private int level = 0;
	private boolean inSelect = false;
	private boolean inFunctionCall = false;
	private boolean inCase = false;
	private boolean inFrom = false;
	private int statementType;
	private String statementTypeName;
	// Note: currentClauseType tracks the current clause within the current
	// statement, regardless of level; currentTopLevelClauseType, on the other
	// hand, tracks the current clause within the top (or primary) statement.
	// Thus, currentTopLevelClauseType ignores the clauses from any subqueries.
	private int currentClauseType;
	private int currentTopLevelClauseType;
	private int currentStatementType;

	public final boolean isSubQuery() {
		return level > 1;
	}

	public final boolean isInFrom() {
		return inFrom;
	}

	public final boolean isInFunctionCall() {
		return inFunctionCall;
	}
	
	public final boolean isInSelect() {
		return inSelect;
	}

	public final boolean isInCase() {
		return inCase;
	}

	public final int getStatementType() {
		return statementType;
	}

	public final int getCurrentClauseType() {
		return currentClauseType;
	}

	public final int getCurrentTopLevelClauseType() {
		return currentTopLevelClauseType;
	}

	public final int getCurrentStatementType() {
		return currentStatementType;
	}

	public final boolean isComparativeExpressionClause() {
		// Note: once we add support for "JOIN ... ON ...",
		// the ON clause needs to get included here
	    return getCurrentClauseType() == WHERE ||
	            getCurrentClauseType() == WITH ||
	            isInCase();
	}

	public final boolean isSelectStatement() {
		return statementType == SELECT;
	}

	private void beforeStatement(String statementName, int statementType) {
		inFunctionCall = false;
		level++;
		if ( level == 1 ) {
			this.statementTypeName = statementName;
			this.statementType = statementType;
		}
		currentStatementType = statementType;
		if ( log.isDebugEnabled() ) {
			log.debug( statementName + " << begin [level=" + level + ", statement=" + this.statementTypeName + "]" );
		}
	}

	private void beforeStatementCompletion(String statementName) {
		if ( log.isDebugEnabled() ) {
			log.debug( statementName + " : finishing up [level=" + level + ", statement=" + statementTypeName + "]" );
		}
	}

	private void afterStatementCompletion(String statementName) {
		if ( log.isDebugEnabled() ) {
			log.debug( statementName + " >> end [level=" + level + ", statement=" + statementTypeName + "]" );
		}
		level--;
	}

	private void handleClauseStart(int clauseType) {
		currentClauseType = clauseType;
		if ( level == 1 ) {
			currentTopLevelClauseType = clauseType;
		}
	}

	///////////////////////////////////////////////////////////////////////////
	// NOTE: The real implementations for the following are in the subclass.

	protected void evaluateAssignment(AST eq) throws SemanticException { }
	
	/** Pre-process the from clause input tree. **/
	protected void prepareFromClauseInputTree(AST fromClauseInput) {}

	/** Sets the current 'FROM' context. **/
	protected void pushFromClause(AST fromClause,AST inputFromNode) {}

	protected AST createFromElement(String path,AST alias,AST propertyFetch) throws SemanticException {
		return null;
	}

	protected void createFromJoinElement(AST path,AST alias,int joinType,AST fetch,AST propertyFetch,AST with) throws SemanticException {}

	protected AST createFromFilterElement(AST filterEntity,AST alias) throws SemanticException	{
		return null;
	}

	protected void processQuery(AST select,AST query) throws SemanticException { }

	protected void postProcessUpdate(AST update) throws SemanticException { }

	protected void postProcessDelete(AST delete) throws SemanticException { }

	protected void postProcessInsert(AST insert) throws SemanticException { }

	protected void beforeSelectClause() throws SemanticException { }

	protected void processIndex(AST indexOp) throws SemanticException { }

	protected void processConstant(AST constant) throws SemanticException { }

	protected void processBoolean(AST constant) throws SemanticException { }

	protected void processNumericLiteral(AST literal) throws SemanticException { }

	protected void resolve(AST node) throws SemanticException { }

	protected void resolveSelectExpression(AST dotNode) throws SemanticException { }

	protected void processFunction(AST functionCall,boolean inSelect) throws SemanticException { }

	protected void processConstructor(AST constructor) throws SemanticException { }

	protected AST generateNamedParameter(AST delimiterNode, AST nameNode) throws SemanticException {
		return #( [NAMED_PARAM, nameNode.getText()] );
	}

	protected AST generatePositionalParameter(AST inputNode) throws SemanticException {
		return #( [PARAM, "?"] );
	}

	protected void lookupAlias(AST ident) throws SemanticException { }

    protected void setAlias(AST selectExpr, AST ident) { }

	protected AST lookupProperty(AST dot,boolean root,boolean inSelect) throws SemanticException {
		return dot;
	}

	protected boolean isNonQualifiedPropertyRef(AST ident) { return false; }

	protected AST lookupNonQualifiedProperty(AST property) throws SemanticException { return property; }

	protected void setImpliedJoinType(int joinType) { }

	protected AST createIntoClause(String path, AST propertySpec) throws SemanticException {
		return null;
	};

	protected void prepareVersioned(AST updateNode, AST versionedNode) throws SemanticException {}

	protected void prepareLogicOperator(AST operator) throws SemanticException { }

	protected void prepareArithmeticOperator(AST operator) throws SemanticException { }
}

// The main statement rule.
statement
	: selectStatement | updateStatement | deleteStatement | insertStatement
	;

selectStatement
	: query
	;

// Cannot use just the fromElement rule here in the update and delete queries
// because fromElement essentially relies on a FromClause already having been
// built :(
updateStatement!
	: #( u:UPDATE { beforeStatement( "update", UPDATE ); } (v:VERSIONED)? f:fromClause s:setClause (w:whereClause)? ) {
		#updateStatement = #(#u, #f, #s, #w);
		beforeStatementCompletion( "update" );
		prepareVersioned( #updateStatement, #v );
		postProcessUpdate( #updateStatement );
		afterStatementCompletion( "update" );
	}
	;

deleteStatement
	: #( DELETE { beforeStatement( "delete", DELETE ); } fromClause (whereClause)? ) {
		beforeStatementCompletion( "delete" );
		postProcessDelete( #deleteStatement );
		afterStatementCompletion( "delete" );
	}
	;

insertStatement
	// currently only "INSERT ... SELECT ..." statements supported;
	// do we also need support for "INSERT ... VALUES ..."?
	//
	: #( INSERT { beforeStatement( "insert", INSERT ); } intoClause query ) {
		beforeStatementCompletion( "insert" );
		postProcessInsert( #insertStatement );
		afterStatementCompletion( "insert" );
	}
	;

intoClause! {
		String p = null;
	}
	: #( INTO { handleClauseStart( INTO ); } (p=path) ps:insertablePropertySpec ) {
		#intoClause = createIntoClause(p, ps);
	}
	;

insertablePropertySpec
	: #( RANGE (IDENT)+ )
	;

setClause
	: #( SET { handleClauseStart( SET ); } (assignment)* )
	;

assignment
	// Note: the propertyRef here needs to be resolved
	// *before* we evaluate the newValue rule...
	: #( EQ (p:propertyRef) { resolve(#p); } (newValue) ) {
		evaluateAssignment( #assignment );
	}
	;

// For now, just use expr.  Revisit after ejb3 solidifies this.
newValue
	: expr | query
	;

// The query / subquery rule. Pops the current 'from node' context 
// (list of aliases).
query!
	: #( QUERY { beforeStatement( "select", SELECT ); }
			// The first phase places the FROM first to make processing the SELECT simpler.
			#(SELECT_FROM
				f:fromClause
				(s:selectClause)?
			)
			(w:whereClause)?
			(g:groupClause)?
			(o:orderClause)?
		) {
		// Antlr note: #x_in refers to the input AST, #x refers to the output AST
		#query = #([SELECT,"SELECT"], #s, #f, #w, #g, #o);
		beforeStatementCompletion( "select" );
		processQuery( #s, #query );
		afterStatementCompletion( "select" );
	}
	;

orderClause
	: #(ORDER { handleClauseStart( ORDER ); } orderExprs)
	;

orderExprs
	: expr ( ASCENDING | DESCENDING )? (orderExprs)?
	;

groupClause
	: #(GROUP { handleClauseStart( GROUP ); } (expr)+ ( #(HAVING logicalExpr) )? )
	;

selectClause!
	: #(SELECT { handleClauseStart( SELECT ); beforeSelectClause(); } (d:DISTINCT)? x:selectExprList ) {
		#selectClause = #([SELECT_CLAUSE,"{select clause}"], #d, #x);
	}
	;

selectExprList {
		boolean oldInSelect = inSelect;
		inSelect = true;
	}
	: ( selectExpr | aliasedSelectExpr )+ {
		inSelect = oldInSelect;
	}