net.sf.saffron.sql
Class SqlValidator

java.lang.Object
  |
  +--net.sf.saffron.sql.SqlValidator

public class SqlValidator

extends Object

SqlValidator validates the parse tree of a SQL statement, and provides semantic information about the parse tree.

Since:

Mar 25, 2003

Version:

$Id: //open/saffron/src/net/sf/saffron/sql/SqlValidator.java#13 $

Author:

jhyde

Nested Class Summary

static interface	SqlValidator.CatalogReader A CatalogReader supplies catalog information for a SqlValidator.
class	SqlValidator.IdentifierScope
(package private) class	SqlValidator.JoinScope The name-resolution scope of a JOIN operator.
class	SqlValidator.Scope Name-resolution scope.
class	SqlValidator.SelectScope The name-resolution scope of a SELECT clause.
(package private) class	SqlValidator.SetopScope
static interface	SqlValidator.Table A Table supplies a SqlValidator with the metadata for a table.
(package private) class	SqlValidator.TableConstructorScope

Field Summary

private SqlValidator.CatalogReader	catalogReader
static String[]	emptyStrings
static SaffronType[]	emptyTypes
private int	nextGeneratedId
SqlOperatorTable	opTab
private SqlNode	outermostNode
private HashMap	scopes Maps query nodes to the scope created from them.
(package private) SaffronTypeFactory	typeFactory

Constructor Summary

SqlValidator(SqlOperatorTable opTab, SqlValidator.CatalogReader catalogReader, SaffronTypeFactory typeFactory)
Creates a validator.

Method Summary

private void	addToSelectList(ArrayList list, List aliases, List types, SqlNode exp, SqlValidator.Scope scope) Adds an expression to a select list, ensuring that its alias does not clash with any existing expressions on the list.
void	check(String s)
void	checkFails(String s, String message)
private SqlSelect	createInternalSelect(SqlNode node, boolean setOutermostNode)
private String	deriveAlias(SqlNode node, int ordinal) Derives an alias for an expression.
(package private) SaffronType	deriveType(SqlValidator.Scope scope, SqlNode operand)
private boolean	expandSelectItem(SqlNode selectItem, SqlSelect select, ArrayList selectItems, List aliases, List types) If selectItem is "*" or "TABLE.*", expands it and returns true; otherwise writes the unexpanded item.
SqlNodeList	expandStar(SqlNodeList selectList, SqlSelect query) Returns a list of expressions, with every occurrence of "*" or "TABLE.*" expanded.
private SqlNode	getChild(SqlSelect select, String alias)
SqlNode	getOutermostNode()
SqlValidator.Scope	getScope(SqlNode node)
SqlValidator.SelectScope	getScope(SqlSelect node)
private SaffronType	getTableConstructorRowType(SqlCall values, SqlValidator.Scope scope)
private boolean	isStar(SqlNode selectItem) Returns whether a select item is "*" or "TABLE.*".
private static SaffronType	lookupField(SaffronType rowType, String columnName)
private RuntimeException	newValidationError(String s)
private void	register(SqlValidator.Scope scope, boolean inFrom) Registers a new scope.
private void	registerFrom(SqlValidator.Scope scope, SqlNode node, String alias)
private void	registerQuery(SqlValidator.Scope scope, SqlNode node, String alias, boolean inFrom)
private void	registerSubqueries(SqlValidator.SelectScope selectScope, SqlNode node)
void	testCrossJoinOnFails()
void	testCrossJoinUsingFails()
void	testDoubleNoAlias()
void	testDuplicateColumnAliasFails()
void	testFromReferenceFails()
void	testIncompatibleUnionFails()
void	testInnerJoinWithoutUsingOrOnFails()
void	testInTooManyColumnsFails()
void	testInvalidGroupBy(TestCase test)
void	testJoinUsingInvalidColsFails()
void	testNaturalCrossJoinFails()
void	testObscuredAliasFails()
void	testSingleNoAlias()
void	testUnionOfNonQueryFails()
void	testWhereReference()
void	validate(SqlNode topNode) Validates a tree.
private void	validateDelete(SqlDelete call)
private void	validateExpression(SqlNode node)
private void	validateFrom(SqlNode node)
private void	validateInsert(SqlInsert call)
void	validateQuery(SqlNode node) Checks that a query (select statement, or a set operation union, intersect, except) is valid.
private void	validateSelect(SqlSelect select)
private void	validateValues(SqlCall node)

Methods inherited from class java.lang.Object

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

Field Detail

opTab

public final SqlOperatorTable opTab

catalogReader

private final SqlValidator.CatalogReader catalogReader

scopes

private HashMap scopes

Maps query nodes to the scope created from them.

outermostNode

private SqlNode outermostNode

nextGeneratedId

private int nextGeneratedId

typeFactory

final SaffronTypeFactory typeFactory

emptyTypes

public static final SaffronType[] emptyTypes

emptyStrings

public static final String[] emptyStrings

Constructor Detail

SqlValidator

public SqlValidator(SqlOperatorTable opTab,
                    SqlValidator.CatalogReader catalogReader,
                    SaffronTypeFactory typeFactory)

Creates a validator.

Pre-condition:

opTab != null, // node is a "query expression" (per SQL standard), catalogReader != null, typeFactory != null

Method Detail

getOutermostNode

public SqlNode getOutermostNode()

getScope

public SqlValidator.SelectScope getScope(SqlSelect node)

check

public void check(String s)

checkFails

public void checkFails(String s,
                       String message)

expandStar

public SqlNodeList expandStar(SqlNodeList selectList,
                              SqlSelect query)

Returns a list of expressions, with every occurrence of "*" or "TABLE.*" expanded.

isStar

private boolean isStar(SqlNode selectItem)

Returns whether a select item is "*" or "TABLE.*".

expandSelectItem

private boolean expandSelectItem(SqlNode selectItem,
                                 SqlSelect select,
                                 ArrayList selectItems,
                                 List aliases,
                                 List types)

If selectItem is "*" or "TABLE.*", expands it and returns true; otherwise writes the unexpanded item.

Parameters:

selectItem - Select-list item

select - Containing select clause

selectItems - List that expanded items are written to

aliases - List of aliases

Returns:

Whether the node was expanded

testDoubleNoAlias

public void testDoubleNoAlias()

testDuplicateColumnAliasFails

public void testDuplicateColumnAliasFails()

testInvalidGroupBy

public void testInvalidGroupBy(TestCase test)

testSingleNoAlias

public void testSingleNoAlias()

testObscuredAliasFails

public void testObscuredAliasFails()

testFromReferenceFails

public void testFromReferenceFails()

testWhereReference

public void testWhereReference()

testIncompatibleUnionFails

public void testIncompatibleUnionFails()

testUnionOfNonQueryFails

public void testUnionOfNonQueryFails()

testInTooManyColumnsFails

public void testInTooManyColumnsFails()

testNaturalCrossJoinFails

public void testNaturalCrossJoinFails()

testCrossJoinUsingFails

public void testCrossJoinUsingFails()

testCrossJoinOnFails

public void testCrossJoinOnFails()

testInnerJoinWithoutUsingOrOnFails

public void testInnerJoinWithoutUsingOrOnFails()

testJoinUsingInvalidColsFails

public void testJoinUsingInvalidColsFails()

validate

public void validate(SqlNode topNode)

Validates a tree. You can call this method only once.

Pre-condition:

getOutermostNode() == null, topNode.getKind().isA(SqlKind.TopLevel)

validateQuery

public void validateQuery(SqlNode node)

Checks that a query (select statement, or a set operation union, intersect, except) is valid.

Throws:

RuntimeException - if the query is not valid

getScope

public SqlValidator.Scope getScope(SqlNode node)

getChild

private SqlNode getChild(SqlSelect select,
                         String alias)

createInternalSelect

private SqlSelect createInternalSelect(SqlNode node,
                                       boolean setOutermostNode)

getTableConstructorRowType

private SaffronType getTableConstructorRowType(SqlCall values,
                                               SqlValidator.Scope scope)

deriveType

SaffronType deriveType(SqlValidator.Scope scope,
                       SqlNode operand)

addToSelectList

private void addToSelectList(ArrayList list,
                             List aliases,
                             List types,
                             SqlNode exp,
                             SqlValidator.Scope scope)

Adds an expression to a select list, ensuring that its alias does not clash with any existing expressions on the list.

deriveAlias

private String deriveAlias(SqlNode node,
                           int ordinal)

Derives an alias for an expression. If no alias can be derived, returns null if ordinal is less than zero, otherwise generates an alias EXPR$ordinal.

newValidationError

private RuntimeException newValidationError(String s)

register

private void register(SqlValidator.Scope scope,
                      boolean inFrom)

Registers a new scope. We assume that its parent pointer has already been set.

Parameters:

scope - Scope to register

inFrom - Whether the scope is in the FROM list of its parent. Only scopes in the FROM list can be returned when resolving identifiers.

registerFrom

private void registerFrom(SqlValidator.Scope scope,
                          SqlNode node,
                          String alias)

registerQuery

private void registerQuery(SqlValidator.Scope scope,
                           SqlNode node,
                           String alias,
                           boolean inFrom)

registerSubqueries

private void registerSubqueries(SqlValidator.SelectScope selectScope,
                                SqlNode node)

validateExpression

private void validateExpression(SqlNode node)

validateFrom

private void validateFrom(SqlNode node)

validateSelect

private void validateSelect(SqlSelect select)

validateInsert

private void validateInsert(SqlInsert call)

validateDelete

private void validateDelete(SqlDelete call)

validateValues

private void validateValues(SqlCall node)

lookupField

private static SaffronType lookupField(SaffronType rowType,
                                       String columnName)