ConstantExpression
Overview
The ConstantExpression implements ConstantExpression and represents values in WhereExpressions.
For example, the following WHERE statement
SELECT * FROM Employees WHERE (Position = 'Sales Manager')
using ConstantExpression would look like this:
WhereExpression lResult;
lResult = new BinaryExpression(
new FieldExpression("Position"),
new ConstantExpression("Sales Manager", DataType.String),
BinaryOperator.Equal),
Location
- Reference: com.remobjects.dataabstract.jar
- Package: com.remobjects.dataabstract.expressions
- Ancestry: Object | WhereExpression | ParameterExpression | ConstantExpression
constructor
Creates an instance of ConstantExpression.
constructor
ConstantExpression()
constructor (String, DataType, Integer) (declared in ParameterExpression)
Creates a new instance of the ParameterExpression class with a specified name, type and size of the parameter.
constructor(aName: String; aType: DataType; aSize: Integer)
ConstantExpression(String aName, DataType aType, Integer aSize)
Parameters:
- aName: The name of the parameter.
- aType: The data type of the parameter.
- aSize: The size of the parameter; used if applicable to the type.
constructor (Object)
Creates an instance of ConstantExpression with the given constant value.
constructor(aValue: Object)
ConstantExpression(Object aValue)
Parameters:
- aValue: The value of the constant.
constructor (Object, DataType)
Creates an instance of ConstantExpression with the given value and data type.
constructor(aValue: Object; aType: DataType)
ConstantExpression(Object aValue, DataType aType)
Parameters:
- aValue: The value of the constant.
- aType: The type of the constant.
combine (WhereExpression, WhereExpression): WhereExpression (declared in WhereExpression)
Creates a new BinaryExpression from the given aLeft and aRight operands using BinaryOperator.
class method combine(aLeft: WhereExpression; aRight: WhereExpression): WhereExpression
static WhereExpression combine(WhereExpression aLeft, WhereExpression aRight)
Parameters:
- aLeft: The left operand to be combined.
- aRight: The right operand to be combined.
combine (WhereExpression, WhereExpression, BinaryOperator): WhereExpression (declared in WhereExpression)
Creates a new BinaryExpression from the given aLeft and aRight operands using the given operator.
class method combine(aLeft: WhereExpression; aRight: WhereExpression; anOperator: BinaryOperator): WhereExpression
static WhereExpression combine(WhereExpression aLeft, WhereExpression aRight, BinaryOperator anOperator)
Parameters:
- aLeft: The left operand to be combined.
- aRight: The right operand to be combined.
- anOperator: The operator to be used in combining.
deserializeObject
Returns the object of the given type from the given provided string.
class method deserializeObject(aSource: String; aDataType: DataType): Object
static Object deserializeObject(String aSource, DataType aDataType)
Parameters:
- aSource: The string to be converted.
- aDataType: The target type of the result value.
fromString (declared in WhereExpression)
Creates a new WhereExpression from the specified string, which should contain XML node in the correct Dynamic Where XML Format.
class method fromString(anXml: String): WhereExpression
static WhereExpression fromString(String anXml)
Parameters:
- anXml: The given XML string.
fromStringToSql (declared in WhereExpression)
A helper method to convert a XML string into SQL string.
class method fromStringToSql(anXml: String): String
static String fromStringToSql(String anXml)
Parameters:
- anXml: The XML string to be converted.
fromXmlNode (declared in WhereExpression)
Creates a new WhereExpression from the given XML node, which should be in the correct Dynamic Where XML Format.
class method fromXmlNode(aNode: Node): WhereExpression
static WhereExpression fromXmlNode(Node aNode)
Parameters:
- aNode: The XML node to be parsed.
Kind
Gets the type of the expression. For the current class, the type is WhereKind.Constant
property Kind: WhereKind read;
WhereKind Kind { __get; }
ParameterName (declared in ParameterExpression)
Name of the parameter represented by this instance.
property ParameterName: String read write;
String ParameterName { __get; __set; }
parseExpression (declared in WhereExpression)
Creates new Where expression from XML node.
class method parseExpression(node: Node): WhereExpression
static WhereExpression parseExpression(Node node)
Parameters:
- node: XML node
readFromXml
Initializes the current expression from the given XML node.
method readFromXml(aNode: Node)
void readFromXml(Node aNode)
Parameters:
- aNode: The XML node to be parsed.
serializeObject
Returns a string representation of the given value in consideration of the specified type.
class method serializeObject(value: Object; dataType: DataType): String
static String serializeObject(Object value, DataType dataType)
Parameters:
- value: The value that is to be converted to string.
- dataType: The type of the provided value.
Size (declared in ParameterExpression)
Size of the parameter.
property Size: Integer read write;
Integer Size { __get; __set; }
toSqlString (declared in WhereExpression)
Creates an SQL representation of the current where expression instance
method toSqlString: String
String toSqlString()
toSqlString (StringBuilder)
Creates an SQL representation of the current where expression instance and appends it to the provided StringBuilder.
method toSqlString(aDestination: StringBuilder)
void toSqlString(StringBuilder aDestination)
Parameters:
- aDestination: The destination string builder to be appended.
toString (declared in WhereExpression)
Returns a SQL string representation of the current expression.
method toString: String
String toString()
toXmlNode (declared in WhereExpression)
Creates a query node (in the Dynamic Where XML Format) from the current expression.
method toXmlNode: Node
Node toXmlNode()
toXmlString (declared in WhereExpression)
Creates the query node (in the Dynamic Where XML Format) from current expression and returns it in the string format.
method toXmlString: String
String toXmlString()
Type (declared in ParameterExpression)
Specifies the type of the parameter. Type can be any from the DataType enum.
property Type: DataType read write;
DataType Type { __get; __set; }
validate (declared in WhereExpression)
Validates the current expression with the WhereValidator and returns TRUE if it contains no errors. The main purpose of the validation is to scan all objects of WhereExpession tree and make sure that they contain correct field names.
method validate: Boolean
Boolean validate()
validate (WhereExpression): Boolean (declared in WhereExpression)
Validates the provided WhereExpression with the WhereValidator and returns TRUE if it contains no errors. The main purpose of the validation is to scan all objects of WhereExpession tree and make sure that it contains correct field names.
class method validate(anExpression: WhereExpression): Boolean
static Boolean validate(WhereExpression anExpression)
Parameters:
- anExpression: The expression to be validated.
Value
Value of the constant
property Value: Object read write;
Object Value { __get; __set; }
writeToXml
Creates where node (in the Dynamic Where XML Format) from expression.
method writeToXml(aNode: Node)
void writeToXml(Node aNode)
Parameters:
- aNode: The given parent XML node.
Kind
Gets the type of the expression. For the current class, the type is WhereKind.Constant
property Kind: WhereKind read;
WhereKind Kind { __get; }
ParameterName (declared in ParameterExpression)
Name of the parameter represented by this instance.
property ParameterName: String read write;
String ParameterName { __get; __set; }
Size (declared in ParameterExpression)
Size of the parameter.
property Size: Integer read write;
Integer Size { __get; __set; }
Type (declared in ParameterExpression)
Specifies the type of the parameter. Type can be any from the DataType enum.
property Type: DataType read write;
DataType Type { __get; __set; }
Value
Value of the constant
property Value: Object read write;
Object Value { __get; __set; }
combine (WhereExpression, WhereExpression): WhereExpression (declared in WhereExpression)
Creates a new BinaryExpression from the given aLeft and aRight operands using BinaryOperator.
class method combine(aLeft: WhereExpression; aRight: WhereExpression): WhereExpression
static WhereExpression combine(WhereExpression aLeft, WhereExpression aRight)
Parameters:
- aLeft: The left operand to be combined.
- aRight: The right operand to be combined.
combine (WhereExpression, WhereExpression, BinaryOperator): WhereExpression (declared in WhereExpression)
Creates a new BinaryExpression from the given aLeft and aRight operands using the given operator.
class method combine(aLeft: WhereExpression; aRight: WhereExpression; anOperator: BinaryOperator): WhereExpression
static WhereExpression combine(WhereExpression aLeft, WhereExpression aRight, BinaryOperator anOperator)
Parameters:
- aLeft: The left operand to be combined.
- aRight: The right operand to be combined.
- anOperator: The operator to be used in combining.
deserializeObject
Returns the object of the given type from the given provided string.
class method deserializeObject(aSource: String; aDataType: DataType): Object
static Object deserializeObject(String aSource, DataType aDataType)
Parameters:
- aSource: The string to be converted.
- aDataType: The target type of the result value.
fromString (declared in WhereExpression)
Creates a new WhereExpression from the specified string, which should contain XML node in the correct Dynamic Where XML Format.
class method fromString(anXml: String): WhereExpression
static WhereExpression fromString(String anXml)
Parameters:
- anXml: The given XML string.
fromStringToSql (declared in WhereExpression)
A helper method to convert a XML string into SQL string.
class method fromStringToSql(anXml: String): String
static String fromStringToSql(String anXml)
Parameters:
- anXml: The XML string to be converted.
fromXmlNode (declared in WhereExpression)
Creates a new WhereExpression from the given XML node, which should be in the correct Dynamic Where XML Format.
class method fromXmlNode(aNode: Node): WhereExpression
static WhereExpression fromXmlNode(Node aNode)
Parameters:
- aNode: The XML node to be parsed.
parseExpression (declared in WhereExpression)
Creates new Where expression from XML node.
class method parseExpression(node: Node): WhereExpression
static WhereExpression parseExpression(Node node)
Parameters:
- node: XML node
serializeObject
Returns a string representation of the given value in consideration of the specified type.
class method serializeObject(value: Object; dataType: DataType): String
static String serializeObject(Object value, DataType dataType)
Parameters:
- value: The value that is to be converted to string.
- dataType: The type of the provided value.
validate (WhereExpression): Boolean (declared in WhereExpression)
Validates the provided WhereExpression with the WhereValidator and returns TRUE if it contains no errors. The main purpose of the validation is to scan all objects of WhereExpession tree and make sure that it contains correct field names.
class method validate(anExpression: WhereExpression): Boolean
static Boolean validate(WhereExpression anExpression)
Parameters:
- anExpression: The expression to be validated.
constructor
Creates an instance of ConstantExpression.
constructor
ConstantExpression()
constructor (String, DataType, Integer) (declared in ParameterExpression)
Creates a new instance of the ParameterExpression class with a specified name, type and size of the parameter.
constructor(aName: String; aType: DataType; aSize: Integer)
ConstantExpression(String aName, DataType aType, Integer aSize)
Parameters:
- aName: The name of the parameter.
- aType: The data type of the parameter.
- aSize: The size of the parameter; used if applicable to the type.
constructor (Object)
Creates an instance of ConstantExpression with the given constant value.
constructor(aValue: Object)
ConstantExpression(Object aValue)
Parameters:
- aValue: The value of the constant.
constructor (Object, DataType)
Creates an instance of ConstantExpression with the given value and data type.
constructor(aValue: Object; aType: DataType)
ConstantExpression(Object aValue, DataType aType)
Parameters:
- aValue: The value of the constant.
- aType: The type of the constant.
readFromXml
Initializes the current expression from the given XML node.
method readFromXml(aNode: Node)
void readFromXml(Node aNode)
Parameters:
- aNode: The XML node to be parsed.
toSqlString (declared in WhereExpression)
Creates an SQL representation of the current where expression instance
method toSqlString: String
String toSqlString()
toSqlString (StringBuilder)
Creates an SQL representation of the current where expression instance and appends it to the provided StringBuilder.
method toSqlString(aDestination: StringBuilder)
void toSqlString(StringBuilder aDestination)
Parameters:
- aDestination: The destination string builder to be appended.
toString (declared in WhereExpression)
Returns a SQL string representation of the current expression.
method toString: String
String toString()
toXmlNode (declared in WhereExpression)
Creates a query node (in the Dynamic Where XML Format) from the current expression.
method toXmlNode: Node
Node toXmlNode()
toXmlString (declared in WhereExpression)
Creates the query node (in the Dynamic Where XML Format) from current expression and returns it in the string format.
method toXmlString: String
String toXmlString()
validate (declared in WhereExpression)
Validates the current expression with the WhereValidator and returns TRUE if it contains no errors. The main purpose of the validation is to scan all objects of WhereExpession tree and make sure that they contain correct field names.
method validate: Boolean
Boolean validate()
writeToXml
Creates where node (in the Dynamic Where XML Format) from expression.
method writeToXml(aNode: Node)
void writeToXml(Node aNode)
Parameters:
- aNode: The given parent XML node.