duckdb::BaseExpression Class Reference

Inheritance diagram for duckdb::BaseExpression:

Collaboration diagram for duckdb::BaseExpression:

Public Member Functions
	BaseExpression (ExpressionType type, ExpressionClass expression_class)
	Create an Expression.
ExpressionClass	GetExpressionClass () const
	Returns the class of the expression.
ExpressionType	GetExpressionType () const
	Returns the type of the expression.
void	SetExpressionTypeUnsafe (ExpressionType new_type)
optional_idx	GetQueryLocation () const
	Returns the location in the query (if any)
void	SetQueryLocation (optional_idx location)
	Sets the location in the query.
bool	HasAlias () const
	Returns true if the expression has a non-empty alias.
const string &	GetAlias () const
	Returns the alias of the expression.
void	SetAlias (const string &alias_p)
	Sets the alias of the expression.
void	SetAlias (string &&alias_p)
	Sets the alias of the expression.
void	ClearAlias ()
	Clears the alias of the expression.
virtual bool	IsAggregate () const =0
	Returns true if this expression is an aggregate or not.
virtual bool	IsWindow () const =0
	Returns true if the expression has a window function or not.
virtual bool	HasSubquery () const =0
	Returns true if the query contains a subquery.
virtual bool	IsScalar () const =0
	Returns true if expression does not contain a group ref or col ref or parameter.
virtual bool	HasParameter () const =0
	Returns true if the expression has a parameter.
virtual string	GetName () const
	Get the name of the expression.
virtual string	ToString () const =0
	Convert the Expression to a String.
void	Print () const
	Print the expression to stdout.
virtual hash_t	Hash () const =0
virtual bool	Equals (const BaseExpression &other) const
	Returns true if this expression is equal to another expression.
bool	operator== (const BaseExpression &rhs) const
virtual void	Verify () const
template<class TARGET >
TARGET &	Cast ()
template<class TARGET >
const TARGET &	Cast () const

Static Public Member Functions
static bool	Equals (const BaseExpression &left, const BaseExpression &right)

Public Attributes
ExpressionType	type
	Type of the expression.
ExpressionClass	expression_class
	The expression class of the node.
string	alias
	The alias of the expression,.
optional_idx	query_location
	The location in the query (if any)

Detailed Description

The BaseExpression class is a base class that can represent any expression part of a SQL statement.

Constructor & Destructor Documentation

BaseExpression()

duckdb::BaseExpression::BaseExpression ( ExpressionType  type, ExpressionClass  expression_class  )

inline

Create an Expression.

        : type(type), expression_class(expression_class) {
    }

~BaseExpression()

virtual duckdb::BaseExpression::~BaseExpression ( )

inlinevirtual

                              {
    }

Member Function Documentation

GetExpressionClass()

ExpressionClass duckdb::BaseExpression::GetExpressionClass ( ) const

inline

Returns the class of the expression.

                                               {
        return expression_class;
    }

GetExpressionType()

ExpressionType duckdb::BaseExpression::GetExpressionType ( ) const

inline

Returns the type of the expression.

                                             {
        return type;
    }

SetExpressionTypeUnsafe()

void duckdb::BaseExpression::SetExpressionTypeUnsafe ( ExpressionType  new_type )

inline

Sets the type of the expression unsafely. In general expressions are immutable and should not be changed after creation. Only use this if you know what you are doing.

                                                          {
        type = new_type;
    }

GetQueryLocation()

optional_idx duckdb::BaseExpression::GetQueryLocation ( ) const

inline

Returns the location in the query (if any)

                                          {
        return query_location;
    }

SetQueryLocation()

void duckdb::BaseExpression::SetQueryLocation ( optional_idx  location )

inline

Sets the location in the query.

                                                 {
        query_location = location;
    }

HasAlias()

bool duckdb::BaseExpression::HasAlias ( ) const

inline

Returns true if the expression has a non-empty alias.

                          {
        return !alias.empty();
    }

GetAlias()

const string & duckdb::BaseExpression::GetAlias ( ) const

inline

Returns the alias of the expression.

                                   {
        return alias;
    }

SetAlias() [1/2]

void duckdb::BaseExpression::SetAlias ( const string &  alias_p )

inline

Sets the alias of the expression.

                                         {
        alias = alias_p;
    }

SetAlias() [2/2]

void duckdb::BaseExpression::SetAlias ( string &&  alias_p )

inline

Sets the alias of the expression.

                                    {
        alias = std::move(alias_p);
    }

ClearAlias()

void duckdb::BaseExpression::ClearAlias ( )

inline

Clears the alias of the expression.

                      {
        alias.clear();
    }

IsAggregate()

virtual bool duckdb::BaseExpression::IsAggregate ( ) const

pure virtual

Returns true if this expression is an aggregate or not.

Examples:

(1) SUM(a) + 1 – True

(2) a + 1 – False

Implemented in duckdb::ParsedExpression, and duckdb::Expression.

IsWindow()

virtual bool duckdb::BaseExpression::IsWindow ( ) const

pure virtual

Returns true if the expression has a window function or not.

Implemented in duckdb::WindowExpression, duckdb::ParsedExpression, and duckdb::Expression.

HasSubquery()

virtual bool duckdb::BaseExpression::HasSubquery ( ) const

pure virtual

Returns true if the query contains a subquery.

Implemented in duckdb::ParsedExpression, and duckdb::Expression.

IsScalar()

virtual bool duckdb::BaseExpression::IsScalar ( ) const

pure virtual

Returns true if expression does not contain a group ref or col ref or parameter.

Implemented in duckdb::ColumnRefExpression, duckdb::LambdaRefExpression, duckdb::BoundColumnRefExpression, duckdb::BoundReferenceExpression, duckdb::ParameterExpression, duckdb::ParsedExpression, and duckdb::Expression.

HasParameter()

virtual bool duckdb::BaseExpression::HasParameter ( ) const

pure virtual

Returns true if the expression has a parameter.

Implemented in duckdb::ParameterExpression, duckdb::ParsedExpression, and duckdb::Expression.

GetName()

virtual string duckdb::BaseExpression::GetName ( ) const

virtual

Get the name of the expression.

Reimplemented in duckdb::ColumnRefExpression, duckdb::LambdaRefExpression, and duckdb::BoundColumnRefExpression.

ToString()

virtual string duckdb::BaseExpression::ToString ( ) const

pure virtual

Convert the Expression to a String.

Implemented in duckdb::ConstantExpression, duckdb::ColumnRefExpression, duckdb::BoundExpression, duckdb::LambdaRefExpression, duckdb::TypeExpression, duckdb::BoundLambdaExpression, duckdb::BoundColumnRefExpression, duckdb::StarExpression, duckdb::FunctionExpression, duckdb::BoundReferenceExpression, duckdb::CastExpression, duckdb::ParameterExpression, duckdb::WindowExpression, duckdb::BoundConstantExpression, duckdb::BoundCastExpression, duckdb::BoundFunctionExpression, and duckdb::LambdaExpression.

Hash()

virtual hash_t duckdb::BaseExpression::Hash ( ) const

pure virtual

Creates a hash value of this expression. It is important that if two expressions are identical (i.e. Expression::Equals() returns true), that their hash value is identical as well.

Implemented in duckdb::ConstantExpression, duckdb::ColumnRefExpression, duckdb::BoundExpression, duckdb::LambdaRefExpression, duckdb::TypeExpression, duckdb::BoundColumnRefExpression, duckdb::FunctionExpression, duckdb::BoundReferenceExpression, duckdb::ParameterExpression, duckdb::BoundConstantExpression, duckdb::BoundFunctionExpression, duckdb::ParsedExpression, duckdb::Expression, and duckdb::LambdaExpression.

Equals() [1/2]

virtual bool duckdb::BaseExpression::Equals ( const BaseExpression &  other ) const

virtual

Returns true if this expression is equal to another expression.

Reimplemented in duckdb::BoundExpression, duckdb::BoundLambdaExpression, duckdb::BoundColumnRefExpression, duckdb::BoundReferenceExpression, duckdb::BoundConstantExpression, duckdb::BoundCastExpression, duckdb::BoundFunctionExpression, duckdb::ParsedExpression, and duckdb::Expression.

Here is the caller graph for this function:

Equals() [2/2]

static bool duckdb::BaseExpression::Equals ( const BaseExpression &  left, const BaseExpression &  right  )

inlinestatic

                                                                                {
        return left.Equals(right);
    }

operator==()

bool duckdb::BaseExpression::operator== ( const BaseExpression &  rhs ) const

inline

                                                     {
        return Equals(rhs);
    }

Cast() [1/2]

template<class TARGET >

TARGET & duckdb::BaseExpression::Cast ( )

inline

                   {
        if (expression_class != TARGET::TYPE) {
            throw InternalException("Failed to cast expression to type - expression type mismatch");
        }
        return reinterpret_cast<TARGET &>(*this);
    }

Cast() [2/2]

template<class TARGET >

const TARGET & duckdb::BaseExpression::Cast ( ) const

inline

                               {
        if (expression_class != TARGET::TYPE) {
            throw InternalException("Failed to cast expression to type - expression type mismatch");
        }
        return reinterpret_cast<const TARGET &>(*this);
    }

---

The documentation for this class was generated from the following file:

• external/duckdb/duckdb.hpp