org.eigenbase.sql

Class SqlCall

java.lang.Object

org.eigenbase.sql.SqlNode

org.eigenbase.sql.SqlCall

All Implemented Interfaces:

Cloneable

Direct Known Subclasses:

SqlBasicCall, SqlCase, SqlDelete, SqlExplain, SqlInsert, SqlJoin, SqlMerge, SqlOrderBy, SqlSelect, SqlSetOption, SqlUpdate, SqlWindow, SqlWith, SqlWithItem

public abstract class SqlCall
extends SqlNode

A SqlCall is a call to an operator. (Operators can be used to describe any syntactic construct, so in practice, every non-leaf node in a SQL parse tree is a SqlCall of some kind.)

Field Summary

Fields inherited from class org.eigenbase.sql.SqlNode

EMPTY_ARRAY

Constructor Summary

Constructors

Constructor and Description
SqlCall(SqlParserPos pos)

Method Summary

Methods

Modifier and Type	Method and Description
<R> R	accept(SqlVisitor<R> visitor) Accepts a generic visitor.
SqlNode	clone(SqlParserPos pos) Clones a SqlNode with a different position.
boolean	equalsDeep(SqlNode node, boolean fail) Returns whether this node is structurally equivalent to another node.
void	findValidOptions(SqlValidator validator, SqlValidatorScope scope, SqlParserPos pos, List<SqlMoniker> hintList) Lists all the valid alternatives for this node if the parse position of the node matches that of pos.
protected String	getCallSignature(SqlValidator validator, SqlValidatorScope scope) Returns a string describing the actual argument types of a call, e.g.
SqlLiteral	getFunctionQuantifier()
SqlMonotonicity	getMonotonicity(SqlValidatorScope scope) Returns whether expression is always ascending, descending or constant.
abstract List<SqlNode>	getOperandList()
abstract SqlOperator	getOperator()
boolean	isCountStar() Test to see if it is the function COUNT(*)
boolean	isExpanded() Whether this call was created by expanding a parentheses-free call to what was syntactically an identifier.
<S extends SqlNode> S	operand(int i)
int	operandCount()
void	setOperand(int i, SqlNode operand) Changes the value of an operand.
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 call.

Methods inherited from class org.eigenbase.sql.SqlNode

clone, cloneArray, equalDeep, equalDeep, getKind, getParserPosition, isA, toSqlString, toSqlString, toString, validateExpr

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlCall

public SqlCall(SqlParserPos pos)

Method Detail

isExpanded

public boolean isExpanded()

Whether this call was created by expanding a parentheses-free call to what was syntactically an identifier.

setOperand

public void setOperand(int i,
              SqlNode operand)

Changes the value of an operand. Allows some rewrite by SqlValidator; use sparingly.

Parameters:

i - Operand index

operand - Operand value

getOperator

public abstract SqlOperator getOperator()

getOperandList

public abstract List<SqlNode> getOperandList()

operand

public <S extends SqlNode> S operand(int i)

operandCount

public int operandCount()

clone

public SqlNode clone(SqlParserPos pos)

Description copied from class: SqlNode

Clones a SqlNode with a different position.

Overrides:

clone in class SqlNode

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 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)

Validates this call.

The default implementation delegates the validation to the operator's SqlOperator.validateCall(org.eigenbase.sql.SqlCall, org.eigenbase.sql.validate.SqlValidator, org.eigenbase.sql.validate.SqlValidatorScope, org.eigenbase.sql.validate.SqlValidatorScope). Derived classes may override (as do, for example SqlSelect and SqlUpdate).

Specified by:

validate in class SqlNode

scope - Validator

findValidOptions

public void findValidOptions(SqlValidator validator,
                    SqlValidatorScope scope,
                    SqlParserPos pos,
                    List<SqlMoniker> hintList)

Description copied from class: SqlNode

Lists all the valid alternatives for this node if the parse position of the node matches that of pos. Only implemented now for SqlCall and SqlOperator.

Overrides:

findValidOptions in class SqlNode

Parameters:

validator - Validator

scope - Validation scope

pos - SqlParserPos indicating the cursor position at which completion hints are requested for

hintList - list of valid options

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

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

getCallSignature

protected String getCallSignature(SqlValidator validator,
                      SqlValidatorScope scope)

Returns a string describing the actual argument types of a call, e.g. "SUBSTR(VARCHAR(12), NUMBER(3,2), INTEGER)".

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.NOT_MONOTONIC.

Overrides:

getMonotonicity in class SqlNode

isCountStar

public boolean isCountStar()

Test to see if it is the function COUNT(*)

Returns:

boolean true if function call to COUNT(*)

getFunctionQuantifier

public SqlLiteral getFunctionQuantifier()