Class NumericTypeCompiler
- java.lang.Object
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- org.apache.derby.impl.sql.compile.BaseTypeCompiler
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- org.apache.derby.impl.sql.compile.NumericTypeCompiler
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- All Implemented Interfaces:
TypeCompiler
public final class NumericTypeCompiler extends BaseTypeCompiler
This class implements TypeId for the SQL numeric datatype.
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Field Summary
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Fields inherited from interface org.apache.derby.iapi.sql.compile.TypeCompiler
AVG_OP, BOOLEAN_MAXWIDTH_AS_CHAR, DEFAULT_DECIMAL_PRECISION, DEFAULT_DECIMAL_SCALE, DIVIDE_OP, DOUBLE_MAXWIDTH_AS_CHAR, INT_MAXWIDTH_AS_CHAR, LONGINT_MAXWIDTH_AS_CHAR, MAX_DECIMAL_PRECISION_SCALE, MINUS_OP, MOD_OP, PLUS_OP, REAL_MAXWIDTH_AS_CHAR, SMALLINT_MAXWIDTH_AS_CHAR, SUM_OP, TIMES_OP, TINYINT_MAXWIDTH_AS_CHAR
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Constructor Summary
Constructors Constructor Description NumericTypeCompiler()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
compatible(TypeId otherType)
Tell whether this type (numeric) is compatible with the given type.boolean
convertible(TypeId otherType, boolean forDataTypeFunction)
Determine if this type can be CONVERTed to some other type(package private) java.lang.String
dataValueMethodName()
Return the method name to get a Derby DataValueDescriptor object of the correct type.void
generateDataValue(MethodBuilder mb, int collationType, LocalField field)
The caller will have pushed a DataValueFactory and value of that can be converted to the correct type, e.g. int for a SQL INTEGER.int
getCastToCharWidth(DataTypeDescriptor dts)
Return the maximum width for this data type when cast to a char type.java.lang.String
getCorrespondingPrimitiveTypeName()
Get the name of the corresponding Java type.private int
getPrecision(java.lang.String operator, DataTypeDescriptor leftType, DataTypeDescriptor rightType)
Get the precision of the operation involving two of the same types.java.lang.String
getPrimitiveMethodName()
Get the method name for getting out the corresponding primitive Java type.private int
getScale(java.lang.String operator, DataTypeDescriptor leftType, DataTypeDescriptor rightType)
Get the scale of the operation involving two of the same types.java.lang.String
interfaceName()
Get the name of the interface for this type.(package private) java.lang.String
nullMethodName()
Return the method name to get a Derby DataValueDescriptor object of the correct type set to SQL NULL.DataTypeDescriptor
resolveArithmeticOperation(DataTypeDescriptor leftType, DataTypeDescriptor rightType, java.lang.String operator)
Type resolution methods on binary operatorsboolean
storable(TypeId otherType, ClassFactory cf)
Determine if this type can have a value of another type stored into it.-
Methods inherited from class org.apache.derby.impl.sql.compile.BaseTypeCompiler
generateNull, getStoredFormatIdFromTypeId, getTypeCompiler, getTypeId, numberConvertible, numberStorable, pushCollationForDataValue, setTypeId, userTypeStorable
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Method Detail
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interfaceName
public java.lang.String interfaceName()
Description copied from interface:TypeCompiler
Get the name of the interface for this type. For example, the interface for a SQLInteger is NumberDataValue. The full path name of the type is returned.- Returns:
- The name of the interface for this type.
- See Also:
TypeCompiler.interfaceName()
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getCorrespondingPrimitiveTypeName
public java.lang.String getCorrespondingPrimitiveTypeName()
Description copied from interface:TypeCompiler
Get the name of the corresponding Java type. For numerics and booleans we will get the corresponding Java primitive type. e Each SQL type has a corresponding Java type. When a SQL value is passed to a Java method, it is translated to its corresponding Java type. For example, a SQL Integer will be mapped to a Java int, but a SQL date will be mapped to a java.sql.Date.- Returns:
- The name of the corresponding Java primitive type.
- See Also:
TypeCompiler.getCorrespondingPrimitiveTypeName()
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getPrimitiveMethodName
public java.lang.String getPrimitiveMethodName()
Get the method name for getting out the corresponding primitive Java type.- Specified by:
getPrimitiveMethodName
in interfaceTypeCompiler
- Overrides:
getPrimitiveMethodName
in classBaseTypeCompiler
- Returns:
- String The method call name for getting the corresponding primitive Java type.
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getCastToCharWidth
public int getCastToCharWidth(DataTypeDescriptor dts)
Description copied from interface:TypeCompiler
Return the maximum width for this data type when cast to a char type.- Parameters:
dts
- The associated DataTypeDescriptor for this TypeId.- Returns:
- int The maximum width for this data type when cast to a char type.
- See Also:
TypeCompiler.getCastToCharWidth(org.apache.derby.iapi.types.DataTypeDescriptor)
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resolveArithmeticOperation
public DataTypeDescriptor resolveArithmeticOperation(DataTypeDescriptor leftType, DataTypeDescriptor rightType, java.lang.String operator) throws StandardException
Description copied from interface:TypeCompiler
Type resolution methods on binary operators- Specified by:
resolveArithmeticOperation
in interfaceTypeCompiler
- Overrides:
resolveArithmeticOperation
in classBaseTypeCompiler
- Parameters:
leftType
- The type of the left parameterrightType
- The type of the right parameteroperator
- The name of the operator (e.g. "+").- Returns:
- The type of the result
- Throws:
StandardException
- Thrown on error- See Also:
TypeCompiler.resolveArithmeticOperation(org.apache.derby.iapi.types.DataTypeDescriptor, org.apache.derby.iapi.types.DataTypeDescriptor, java.lang.String)
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convertible
public boolean convertible(TypeId otherType, boolean forDataTypeFunction)
Description copied from interface:TypeCompiler
Determine if this type can be CONVERTed to some other type- Parameters:
otherType
- The CompilationType of the other type to compare this type toforDataTypeFunction
- true if this is a type function that requires more liberal behavior (e.g DOUBLE can convert a char but you cannot cast a CHAR to double.- Returns:
- true if the types can be converted, false if conversion is not allowed
- See Also:
TypeCompiler.convertible(org.apache.derby.iapi.types.TypeId, boolean)
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compatible
public boolean compatible(TypeId otherType)
Tell whether this type (numeric) is compatible with the given type.- Parameters:
otherType
- The TypeId of the other type.- Returns:
- true if the types are compatible, false if not compatible
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storable
public boolean storable(TypeId otherType, ClassFactory cf)
Description copied from interface:TypeCompiler
Determine if this type can have a value of another type stored into it. Note that direction is relevant here: the test is that the otherType is storable into this type.- Parameters:
otherType
- The TypeId of the other type to compare this type tocf
- A ClassFactory- Returns:
- true if the other type can be stored in a column of this type.
- See Also:
TypeCompiler.storable(org.apache.derby.iapi.types.TypeId, org.apache.derby.iapi.services.loader.ClassFactory)
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dataValueMethodName
java.lang.String dataValueMethodName()
Return the method name to get a Derby DataValueDescriptor object of the correct type. This implementation returns"getDataValue"
, unless the type isDECIMAL
, in which case"getDecimalDataValue"
is returned.- Overrides:
dataValueMethodName
in classBaseTypeCompiler
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nullMethodName
java.lang.String nullMethodName()
Description copied from class:BaseTypeCompiler
Return the method name to get a Derby DataValueDescriptor object of the correct type set to SQL NULL. The method named will be called with one argument: a holder object if pushCollationForDataValue() returns false, otherwise two arguments, the second being the collationType.- Specified by:
nullMethodName
in classBaseTypeCompiler
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getPrecision
private int getPrecision(java.lang.String operator, DataTypeDescriptor leftType, DataTypeDescriptor rightType)
Get the precision of the operation involving two of the same types. Only meaningful for decimals, which override this.- Parameters:
operator
- a string representing the operator, null means no operator, just a type mergeleftType
- the left typerightType
- the left type- Returns:
- the resultant precision
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getScale
private int getScale(java.lang.String operator, DataTypeDescriptor leftType, DataTypeDescriptor rightType)
Get the scale of the operation involving two of the same types. Since we don't really have a good way to pass the resultant scale and precision around at execution time, we will model that BigDecimal does by default. This is good in most cases, though we would probably like to use something more sophisticated for division.- Parameters:
operator
- a string representing the operator, null means no operator, just a type mergeleftType
- the left typerightType
- the left type- Returns:
- the resultant precision
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generateDataValue
public void generateDataValue(MethodBuilder mb, int collationType, LocalField field)
Description copied from class:BaseTypeCompiler
The caller will have pushed a DataValueFactory and value of that can be converted to the correct type, e.g. int for a SQL INTEGER. Thus upon entry the stack looks like: ...,dvf,value If field is not null then it is used as the holder of the generated DataValueDescriptor to avoid object creations on multiple passes through this code. The field may contain null or a valid value. This method then sets up to call the required method on DataValueFactory using the dataValueMethodName(). The value left on the stack will be a DataValueDescriptor of the correct type: If the field contained a valid value then generated code will return that value rather than a newly created object. If field was not-null then the generated code will set the value of field to be the return from the DataValueFactory method call. Thus if the field was empty (set to null) when this code is executed it will contain the newly generated value, otherwise it will be reset to the same value. ...,dvd- Specified by:
generateDataValue
in interfaceTypeCompiler
- Overrides:
generateDataValue
in classBaseTypeCompiler
- Parameters:
mb
- The method to put the expression incollationType
- For character DVDs, this will be used to determine what Collator should be associated with the DVD which in turn will decide whether to generate CollatorSQLcharDVDs or SQLcharDVDs. For other types of DVDs, this parameter will be ignored.field
- LocalField- See Also:
TypeCompiler.generateDataValue(MethodBuilder, int, LocalField)
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