org.eigenbase.sql
Class SqlIdentifier

java.lang.Object
  org.eigenbase.sql.SqlNode
      org.eigenbase.sql.SqlIdentifier

All Implemented Interfaces:

Cloneable

public class SqlIdentifier
extends SqlNode

A SqlIdentifier is an identifier, possibly compound.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/sql/SqlIdentifier.java#34 $

Author:

jhyde

Field Summary

(package private) SqlCollation	collation This identifier's collation (if any).
private SqlParserPos[]	componentPositions A list of the positions of the components of compound identifiers.
String[]	names Array of the components of this compound identifier.

Fields inherited from class org.eigenbase.sql.SqlNode

emptyArray

Constructor Summary

SqlIdentifier(String[] names, SqlCollation collation, SqlParserPos pos, SqlParserPos[] componentPositions)
Creates a compound identifier, for example foo.bar.

SqlIdentifier(String[] names, SqlParserPos pos)

SqlIdentifier(String name, SqlCollation collation, SqlParserPos pos)
Creates a simple identifier, for example foo, with a collation.

SqlIdentifier(String name, SqlParserPos pos)
Creates a simple identifier, for example foo.

Method Summary

<R> R	accept(SqlVisitor<R> visitor) Accepts a generic visitor.
void	assignNamesFrom(SqlIdentifier other) Copies names and components from another identifier.
SqlNode	clone(SqlParserPos pos) Clones a SqlNode with a different position.
boolean	equalsBaseName(String name)
boolean	equalsDeep(SqlNode node, boolean fail) Returns whether this node is structurally equivalent to another node.
SqlCollation	getCollation()
SqlIdentifier	getComponent(int ordinal) Creates an identifier which contains only the ordinalth component of this compound identifier.
SqlParserPos	getComponentParserPosition(int i) Returns the position of the ith component of a compound identifier, or the position of the whole identifier if that information is not present.
SqlKind	getKind() Returns the type of node this is, or SqlKind.Other if it's nothing special.
SqlMonotonicity	getMonotonicity(SqlValidatorScope scope) Returns whether expression is always ascending, descending or constant.
String	getSimple()
boolean	isSimple() Returns whether this is a simple identifier.
boolean	isStar() Returns whether this identifier is a star, such as "*" or "foo.bar.*".
void	setNames(String[] names, SqlParserPos[] poses) Deprecated. Identifiers should be immutable
String	toString()
void	unparse(SqlWriter writer, int leftPrec, int rightPrec) Writes a SQL representation of this node to a writer.
void	validate(SqlValidator validator, SqlValidatorScope scope) Validates this node.
void	validateExpr(SqlValidator validator, SqlValidatorScope scope) Validates this node in an expression context.

Methods inherited from class org.eigenbase.sql.SqlNode

clone, cloneArray, equalDeep, findValidOptions, getParserPosition, isA, toSqlString, toSqlString

Methods inherited from class java.lang.Object

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

Field Detail

names

public String[] names

Array of the components of this compound identifier.

It's convenient to have this member public, and it's convenient to have this member not-final, but it's a shame it's public and not-final. If you assign to this member, please use setNames(String[], SqlParserPos[]). And yes, we'd like to make identifiers immutable one day.

collation

SqlCollation collation

This identifier's collation (if any).

componentPositions

private SqlParserPos[] componentPositions

A list of the positions of the components of compound identifiers.

Constructor Detail

SqlIdentifier

public SqlIdentifier(String[] names,
                     SqlCollation collation,
                     SqlParserPos pos,
                     SqlParserPos[] componentPositions)

Creates a compound identifier, for example foo.bar.

Parameters:

names - Parts of the identifier, length >= 1

SqlIdentifier

public SqlIdentifier(String[] names,
                     SqlParserPos pos)

SqlIdentifier

public SqlIdentifier(String name,
                     SqlCollation collation,
                     SqlParserPos pos)

Creates a simple identifier, for example foo, with a collation.

SqlIdentifier

public SqlIdentifier(String name,
                     SqlParserPos pos)

Creates a simple identifier, for example foo.

Method Detail

getKind

public SqlKind getKind()

Description copied from class: SqlNode

Returns the type of node this is, or SqlKind.Other if it's nothing special.

Overrides:

getKind in class SqlNode

Returns:

a SqlKind value, never null

clone

public SqlNode clone(SqlParserPos pos)

Description copied from class: SqlNode

Clones a SqlNode with a different position.

Overrides:

clone in class SqlNode

toString

public String toString()

Overrides:

toString in class SqlNode

setNames

public void setNames(String[] names,
                     SqlParserPos[] poses)

Deprecated. Identifiers should be immutable

Modifies the components of this identifier and their positions.

Parameters:

names - Names of components

poses - Positions of components

getComponentParserPosition

public SqlParserPos getComponentParserPosition(int i)

Returns the position of the ith component of a compound identifier, or the position of the whole identifier if that information is not present.

Parameters:

i - Ordinal of component.

Returns:

Position of i'th component

assignNamesFrom

public void assignNamesFrom(SqlIdentifier other)

Copies names and components from another identifier. Does not modify the cross-component parser position.

Parameters:

other - identifer from which to copy

getComponent

public SqlIdentifier getComponent(int ordinal)

Creates an identifier which contains only the ordinalth component of this compound identifier. It will have the correct SqlParserPos, provided that detailed position information is available.

unparse

public void unparse(SqlWriter writer,
                    int leftPrec,
                    int rightPrec)

Description copied from class: SqlNode

Writes a SQL representation of this node to a writer.

The leftPrec and rightPrec parameters give us enough context to decide whether we need to enclose the expression in parentheses. For example, we need parentheses around "2 + 3" if preceded by "5 *". This is because the precedence of the "*" operator is greater than the precedence of the "+" operator.

The algorithm handles left- and right-associative operators by giving them slightly different left- and right-precedence.

If SqlWriter.isAlwaysUseParentheses() is true, we use parentheses even when they are not required by the precedence rules.

For the details of this algorithm, see SqlCall.unparse(org.eigenbase.sql.SqlWriter, int, int).

Specified by:

unparse in class SqlNode

Parameters:

writer - Target writer

leftPrec - The precedence of the SqlNode immediately preceding this node in a depth-first scan of the parse tree

rightPrec - The precedence of the SqlNode immediately

validate

public void validate(SqlValidator validator,
                     SqlValidatorScope scope)

Description copied from class: SqlNode

Validates this node.

The typical implementation of this method will make a callback to the validator appropriate to the node type and context. The validator has methods such as SqlValidator.validateLiteral(org.eigenbase.sql.SqlLiteral) for these purposes.

Specified by:

validate in class SqlNode

scope - Validator

validateExpr

public void validateExpr(SqlValidator validator,
                         SqlValidatorScope scope)

Description copied from class: SqlNode

Validates this node in an expression context.

Usually, this method does much the same as SqlNode.validate(org.eigenbase.sql.validate.SqlValidator, org.eigenbase.sql.validate.SqlValidatorScope), but a SqlIdentifier can occur in expression and non-expression contexts.

Overrides:

validateExpr in class SqlNode

equalsDeep

public boolean equalsDeep(SqlNode node,
                          boolean fail)

Description copied from class: SqlNode

Returns whether this node is structurally equivalent to another node. Some examples:

• 1 + 2 is structurally equivalent to 1 + 2
• 1 + 2 + 3 is structurally equivalent to (1 + 2) + 3, but not to 1 + (2 + 3), because the '+' operator is left-associative

Specified by:

equalsDeep in class SqlNode

accept

public <R> R accept(SqlVisitor<R> visitor)

Description copied from class: SqlNode

Accepts a generic visitor.

Implementations of this method in subtypes simply call the appropriate visit method on the visitor object.

The type parameter R must be consistent with the type parameter of the visitor.

Specified by:

accept in class SqlNode

getCollation

public SqlCollation getCollation()

getSimple

public String getSimple()

isStar

public boolean isStar()

Returns whether this identifier is a star, such as "*" or "foo.bar.*".

isSimple

public boolean isSimple()

Returns whether this is a simple identifier. "FOO" is simple; "*", "FOO.*" and "FOO.BAR" are not.

getMonotonicity

public SqlMonotonicity getMonotonicity(SqlValidatorScope scope)

Description copied from class: SqlNode

Returns whether expression is always ascending, descending or constant. This property is useful because it allows to safely aggregte infinite streams of values.

The default implementation returns SqlMonotonicity.NotMonotonic.

Overrides:

getMonotonicity in class SqlNode

equalsBaseName

public boolean equalsBaseName(String name)