Field Detail

• UNKNOWN_LOGICAL_LENGTH

  static final int UNKNOWN_LOGICAL_LENGTH

  Constant indicating that the logical length of a value (i.e. chars for string types or bytes for binary types) is unknown.

  See Also:

  Constant Field Values

Method Detail

• getLength

  int getLength()
         throws StandardException

  Gets the length of the data value. The meaning of this is implementation-dependent. For string types, it is the number of characters in the string. For numeric types, it is the number of bytes used to store the number. This is the actual length of this value, not the length of the type it was defined as. For example, a VARCHAR value may be shorter than the declared VARCHAR (maximum) length.

  Returns:

  The length of the data value

  Throws:

  StandardException - On error

• getString

  java.lang.String getString()
                      throws StandardException

  Gets the value in the data value descriptor as a String. Throws an exception if the data value is not a string.

  Returns:

  The data value as a String.

  Throws:

  StandardException - Thrown on error

• getTraceString

  java.lang.String getTraceString()
                           throws StandardException

  Gets the value in the data value descriptor as a trace string. If the value itself is not suitable for tracing purposes, a more suitable representation is returned. For instance, data values represented as streams are not materialized. Instead, information about the associated stream is given.

  Throws:

  StandardException

• getBoolean

  boolean getBoolean()
              throws StandardException

  Gets the value in the data value descriptor as a boolean. Throws an exception if the data value is not a boolean. For DataValueDescriptor, this is the preferred interface for BIT, but for this no-casting interface, it isn't, because BIT is stored internally as a Bit, not as a Boolean.

  Returns:

  The data value as a boolean.

  Throws:

  StandardException - Thrown on error

• getByte

  byte getByte()
        throws StandardException

  Gets the value in the data value descriptor as a byte. Throws an exception if the data value is not a byte.

  Returns:

  The data value as a byte.

  Throws:

  StandardException - Thrown on error

• getShort

  short getShort()
          throws StandardException

  Gets the value in the data value descriptor as a short. Throws an exception if the data value is not a short.

  Returns:

  The data value as a short.

  Throws:

  StandardException - Thrown on error

• getInt

  int getInt()
      throws StandardException

  Gets the value in the data value descriptor as an int. Throws an exception if the data value is not an int.

  Returns:

  The data value as a int.

  Throws:

  StandardException - Thrown on error

• getLong

  long getLong()
        throws StandardException

  Gets the value in the data value descriptor as a long. Throws an exception if the data value is not a long.

  Returns:

  The data value as a long.

  Throws:

  StandardException - Thrown on error

• getFloat

  float getFloat()
          throws StandardException

  Gets the value in the data value descriptor as a float. Throws an exception if the data value is not a float.

  Returns:

  The data value as a float.

  Throws:

  StandardException - Thrown on error

• getDouble

  double getDouble()
            throws StandardException

  Gets the value in the data value descriptor as a double. Throws an exception if the data value is not a double.

  Returns:

  The data value as a double.

  Throws:

  StandardException - Thrown on error

• typeToBigDecimal

  int typeToBigDecimal()
                throws StandardException

  How should this value be obtained so that it can be converted to a BigDecimal representation.

  Returns:

  Types.CHAR for String conversion through getString Types.DECIMAL for BigDecimal through getObject or Types.BIGINT for long conversion through getLong

  Throws:

  StandardException - Conversion is not possible

• getBytes

  byte[] getBytes()
           throws StandardException

  Gets the value in the data value descriptor as a byte array. Throws an exception if the data value is not a byte array.

  Returns:

  The data value as a byte[].

  Throws:

  StandardException - Thrown on error

• getDate

  java.sql.Date getDate​(java.util.Calendar cal)
                 throws StandardException

  Gets the value in the data value descriptor as a java.sql.Date. Throws an exception if the data value is not a Date.

  Parameters:

  cal - calendar for object creation

  Returns:

  The data value as a java.sql.Date.

  Throws:

  StandardException - Thrown on error

• getTime

  java.sql.Time getTime​(java.util.Calendar cal)
                 throws StandardException

  Gets the value in the data value descriptor as a java.sql.Time. Throws an exception if the data value is not a Time.

  Parameters:

  cal - calendar for object creation

  Returns:

  The data value as a java.sql.Time.

  Throws:

  StandardException - Thrown on error

• getTimestamp

  java.sql.Timestamp getTimestamp​(java.util.Calendar cal)
                           throws StandardException

  Gets the value in the data value descriptor as a java.sql.Timestamp. Throws an exception if the data value is not a Timestamp.

  Parameters:

  cal - calendar for object creation

  Returns:

  The data value as a java.sql.Timestamp.

  Throws:

  StandardException - Thrown on error

• getObject

  java.lang.Object getObject()
                      throws StandardException

  Gets the value in the data value descriptor as a Java Object. The type of the Object will be the Java object type corresponding to the data value's SQL type. JDBC defines a mapping between Java object types and SQL types - we will allow that to be extended through user type definitions. Throws an exception if the data value is not an object (yeah, right).

  Returns:

  The data value as an Object.

  Throws:

  StandardException - Thrown on error

• getStream

  java.io.InputStream getStream()
                         throws StandardException

  Gets the value in the data value descriptor as a stream of bytes.

  Only data types that implement StreamStorable will have stream states, and the method hasStream should be called to determine if the value in question is, or will be, represented by a stream.

  Returns:

  The stream state of the data value.

  Throws:

  StandardException - Throws an exception if the data value cannot be received as a stream.

  See Also:

  hasStream(), StringDataValue.getStreamWithDescriptor()

• hasStream

  boolean hasStream()

  Tells if this data value is, or will be, represented by a stream.

  This method should be called to determine if the methods getStream or DataValueDescriptor.getStreamWithDescriptor can be invoked.

  Returns:

  true if the value will be a stream, false otherwise.

  See Also:

  getStream(), StringDataValue.getStreamWithDescriptor()

• cloneHolder

  DataValueDescriptor cloneHolder()

  Get a shallow copy of this codeDataValueDescriptor (DVD).

  The primary use of this method is to avoid materializing streams for data types like BLOB and CLOB.

  In general the orginal DVD should be recycled or discarded when this method is invoked to ensure that changes to the original DVD don't affect the clone (or the other way around). Note that it is not safe to assume that a number of these clones can be used for read-only access to the same value.

  Implementation note: The reason why the clones can't be guaranteed to work as "read clones" is that if the value is represented as a stream, the state of the stream will change on read operations. Since all the clones share the same stream, this may lead to wrong results, data corruption or crashes.

  Returns:

  A clone of this descriptor, which shares the internal state.

• cloneValue

  DataValueDescriptor cloneValue​(boolean forceMaterialization)

  Clone this DataValueDescriptor. Results in a new object that has the same value as this but can be modified independently.

  Even though the objects can be modified independently regardless of the value of forceMaterialization, both the clone and the original may be dependent on the store state if forceMaterialization is set to false. An example is if you need to access the value you just read using cloneValue after the current transaction has ended, or after the source result set has been closed.

  Parameters:

  forceMaterialization - any streams representing the data value will be materialized if true, the data value will be kept as a stream if possible if false

  Returns:

  A clone of the DataValueDescriptor with the same initial value as this.

• recycle

  DataValueDescriptor recycle()

  Recycle this DataValueDescriptor if possible. Create and return a new object if it cannot be recycled.

  Returns:

  this object with the value set to null, or a new DataValueDescriptor of the same type as this

• getNewNull

  DataValueDescriptor getNewNull()

  Get a new null value of the same type as this data value.

• setValueFromResultSet

  void setValueFromResultSet​(java.sql.ResultSet resultSet,
                             int colNumber,
                             boolean isNullable)
                      throws StandardException,
                             java.sql.SQLException

  Set the value based on the value for the specified DataValueDescriptor from the specified ResultSet.

  Parameters:

  resultSet - The specified ResultSet.

  colNumber - The 1-based column # into the resultSet.

  isNullable - Whether or not the column is nullable (No need to call wasNull() if not)

  Throws:

  StandardException - Thrown on error

  java.sql.SQLException - Error accessing the result set

• setInto

  void setInto​(java.sql.PreparedStatement ps,
               int position)
        throws java.sql.SQLException,
               StandardException

  Set this value into a PreparedStatement. This method must handle setting NULL into the PreparedStatement.

  Throws:

  java.sql.SQLException - thrown by the PreparedStatement object

  StandardException - thrown by me accessing my value.

• setInto

  void setInto​(java.sql.ResultSet rs,
               int position)
        throws java.sql.SQLException,
               StandardException

  Set this value into a ResultSet for a subsequent ResultSet.insertRow or ResultSet.updateRow. This method will only be called for non-null values.

  Throws:

  java.sql.SQLException - thrown by the ResultSet object

  StandardException - thrown by me accessing my value.

• setValue

  void setValue​(int theValue)
         throws StandardException

  Set the value of this DataValueDescriptor to the given int value

  Parameters:

  theValue - The value to set this DataValueDescriptor to

  Throws:

  StandardException - Thrown on error

• setValue

  void setValue​(double theValue)
         throws StandardException

  Set the value of this DataValueDescriptor to the given double value

  Parameters:

  theValue - The value to set this DataValueDescriptor to

  Throws:

  StandardException - Thrown on error

• setValue

  void setValue​(float theValue)
         throws StandardException

  Set the value of this DataValueDescriptor to the given double value

  Parameters:

  theValue - A Double containing the value to set this DataValueDescriptor to. Null means set the value to SQL null.

  Throws:

  StandardException - Thrown on error

• setValue

  void setValue​(short theValue)
         throws StandardException

  Set the value of this DataValueDescriptor to the given short value

  Parameters:

  theValue - The value to set this DataValueDescriptor to

  Throws:

  StandardException - Thrown on error

• setValue

  void setValue​(long theValue)
         throws StandardException

  Set the value of this DataValueDescriptor to the given long value

  Parameters:

  theValue - The value to set this DataValueDescriptor to

  Throws:

  StandardException - Thrown on error

• setValue

  void setValue​(byte theValue)
         throws StandardException

  Set the value of this DataValueDescriptor to the given byte value

  Parameters:

  theValue - The value to set this DataValueDescriptor to

  Throws:

  StandardException

• setValue

  void setValue​(boolean theValue)
         throws StandardException

  Set the value.

  Parameters:

  theValue - Contains the boolean value to set this to

  Throws:

  StandardException

• setValue

  void setValue​(java.lang.Object theValue)
         throws StandardException

  Set the value of this DataValueDescriptor to the given Object value

  Parameters:

  theValue - The value to set this DataValueDescriptor to

  Throws:

  StandardException - Thrown on error

• setValue

  void setValue​(byte[] theValue)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The byte value to set this DataValueDescriptor to

  Throws:

  StandardException

• setBigDecimal

  void setBigDecimal​(java.math.BigDecimal bigDecimal)
              throws StandardException

  Set this value from an application supplied java.math.BigDecimal. This is to support the PreparedStatement.setBigDecimal method and similar JDBC methods that allow an application to pass in a BigDecimal to any SQL type.

  Parameters:

  bigDecimal - required to be a BigDecimal or null.

  Throws:

  StandardException

• setValue

  void setValue​(java.lang.String theValue)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The String value to set this DataValueDescriptor to

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Blob theValue)
         throws StandardException

  Set the value of this DataValueDescriptor from a Blob.

  Parameters:

  theValue - The Blob value to set this DataValueDescriptor to

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Clob theValue)
         throws StandardException

  Set the value of this DataValueDescriptor from a Clob.

  Parameters:

  theValue - The Clob value to set this DataValueDescriptor to

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Time theValue)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The Time value to set this DataValueDescriptor to

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Time theValue,
                java.util.Calendar cal)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The Time value to set this DataValueDescriptor to

  cal - The time zone from the calendar is used to construct the database time value

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Timestamp theValue)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The Timestamp value to set this DataValueDescriptor to

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Timestamp theValue,
                java.util.Calendar cal)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The Timestamp value to set this DataValueDescriptor to

  cal - The time zone from the calendar is used to construct the database timestamp value

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Date theValue)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The Date value to set this DataValueDescriptor to

  Throws:

  StandardException

• setValue

  void setValue​(java.sql.Date theValue,
                java.util.Calendar cal)
         throws StandardException

  Set the value of this DataValueDescriptor.

  Parameters:

  theValue - The Date value to set this DataValueDescriptor to

  cal - The time zone from the calendar is used to construct the database date value

  Throws:

  StandardException

• setValue

  void setValue​(DataValueDescriptor theValue)
         throws StandardException

  Set the value of this DataValueDescriptor from another.

  Parameters:

  theValue - The Date value to set this DataValueDescriptor to

  Throws:

  StandardException

• setToNull

  void setToNull()

  Set the value to SQL null.

• normalize

  void normalize​(DataTypeDescriptor dtd,
                 DataValueDescriptor source)
          throws StandardException

  Normalize the source value to this type described by this class and the passed in DataTypeDescriptor. The type of the DataTypeDescriptor must match this class.

  Throws:

  StandardException

• isNullOp

  BooleanDataValue isNullOp()

  The SQL "IS NULL" operator. Returns true if this value is null. *

  Returns:

  True if this value is null.

• isNotNull

  BooleanDataValue isNotNull()

  The SQL "IS NOT NULL" operator. Returns true if this value is not null.

  Returns:

  True if this value is not null.

• getTypeName

  java.lang.String getTypeName()

  Get the SQL name of the datatype

  Returns:

  The SQL name of the datatype

• setObjectForCast

  void setObjectForCast​(java.lang.Object value,
                        boolean instanceOfResultType,
                        java.lang.String resultTypeClassName)
                 throws StandardException

  Set this value from an Object. Used from CAST of a Java type to another type, including SQL types. If the passed instanceOfResultType is false then the object is not an instance of the declared type resultTypeClassName. Usually an exception should be thrown.

  Parameters:

  value - The new value

  instanceOfResultType - Whether or not the new value is an instanceof the result type.

  resultTypeClassName - The class name of the resulting (declared) type (for error messages only).

  Throws:

  StandardException - Thrown on error

• readExternalFromArray

  void readExternalFromArray​(ArrayInputStream ais)
                      throws java.io.IOException,
                             java.lang.ClassNotFoundException

  Read the DataValueDescriptor from the stream.

  Initialize the data value by reading it's values from the ArrayInputStream. This interface is provided as a way to achieve possible performance enhancement when reading an array can be optimized over reading from a generic stream from readExternal().

  Parameters:

  ais - The array stream positioned at the beginning of the byte stream to read from.

  Throws:

  java.io.IOException - Usual error is if you try to read past limit on the stream.

  java.lang.ClassNotFoundException - If a necessary class can not be found while reading the object from the stream.

• typePrecedence

  int typePrecedence()

  Each built-in type in JSQL has a precedence. This precedence determines how to do type promotion when using binary operators. For example, float has a higher precedence than int, so when adding an int to a float, the result type is float. The precedence for some types is arbitrary. For example, it doesn't matter what the precedence of the boolean type is, since it can't be mixed with other types. But the precedence for the number types is critical. The SQL standard requires that exact numeric types be promoted to approximate numeric when one operator uses both. Also, the precedence is arranged so that one will not lose precision when promoting a type.

  Returns:

  The precedence of this type.

• equals

  BooleanDataValue equals​(DataValueDescriptor left,
                          DataValueDescriptor right)
                   throws StandardException

  The SQL language = operator. This method is called from the language module. The storage module uses the compare method in Orderable.

  Parameters:

  left - The value on the left side of the operator

  right - The value on the right side of the operator

  Returns:

  A BooleanDataValue telling the result of the comparison

  Throws:

  StandardException - Thrown on error

• notEquals

  BooleanDataValue notEquals​(DataValueDescriptor left,
                             DataValueDescriptor right)
                      throws StandardException

  The SQL language <> operator. This method is called from the language module. The storage module uses the compare method in Orderable.

  Parameters:

  left - The value on the left side of the operator

  right - The value on the right side of the operator

  Returns:

  A BooleanDataValue telling the result of the comparison

  Throws:

  StandardException - Thrown on error

• lessThan

  BooleanDataValue lessThan​(DataValueDescriptor left,
                            DataValueDescriptor right)
                     throws StandardException

  The SQL language < operator. This method is called from the language module. The storage module uses the compare method in Orderable.

  Parameters:

  left - The value on the left side of the operator

  right - The value on the right side of the operator

  Returns:

  A BooleanDataValue telling the result of the comparison

  Throws:

  StandardException - Thrown on error

• greaterThan

  BooleanDataValue greaterThan​(DataValueDescriptor left,
                               DataValueDescriptor right)
                        throws StandardException

  The SQL language > operator. This method is called from the language module. The storage module uses the compare method in Orderable.

  Parameters:

  left - The value on the left side of the operator

  right - The value on the right side of the operator

  Returns:

  A BooleanDataValue telling the result of the comparison

  Throws:

  StandardException - Thrown on error

• lessOrEquals

  BooleanDataValue lessOrEquals​(DataValueDescriptor left,
                                DataValueDescriptor right)
                         throws StandardException

  The SQL language <= operator. This method is called from the language module. The storage module uses the compare method in Orderable.

  Parameters:

  left - The value on the left side of the operator

  right - The value on the right side of the operator

  Returns:

  A BooleanDataValue telling the result of the comparison

  Throws:

  StandardException - Thrown on error

• greaterOrEquals

  BooleanDataValue greaterOrEquals​(DataValueDescriptor left,
                                   DataValueDescriptor right)
                            throws StandardException

  The SQL language >= operator. This method is called from the language module. The storage module uses the compare method in Orderable.

  Parameters:

  left - The value on the left side of the operator

  right - The value on the right side of the operator

  Returns:

  A BooleanDataValue telling the result of the comparison

  Throws:

  StandardException - Thrown on error

• coalesce

  DataValueDescriptor coalesce​(DataValueDescriptor[] list,
                               DataValueDescriptor returnValue)
                        throws StandardException

  The SQL language COALESCE/VALUE function. This method is called from the language module.

  Parameters:

  list - The list of the arguments. Function will return the first non-nullable argument if any.

  returnValue - The return value is the correct datatype for this function. The return value of this method is the type of the 2nd parameter.

  Returns:

  A DataValueDescriptor which will be either null or first non-null argument

  Throws:

  StandardException - Thrown on error

• in

  BooleanDataValue in​(DataValueDescriptor left,
                      DataValueDescriptor[] inList,
                      boolean orderedList)
               throws StandardException

  The SQL language IN operator. This method is called from the language module. This method allows us to optimize and short circuit the search if the list is ordered.

  Parameters:

  left - The value on the left side of the operator

  inList - The values in the IN list

  orderedList - True means that the values in the IN list are ordered, false means they are not.

  Returns:

  A BooleanDataValue telling the result of the comparison

  Throws:

  StandardException - Thrown on error

• compare

  int compare​(DataValueDescriptor other)
       throws StandardException

  Compare this Orderable with a given Orderable for the purpose of index positioning. This method treats nulls as ordered values - that is, it treats SQL null as equal to null and greater than all other values.

  Parameters:

  other - The Orderable to compare this one to.

  Returns:

  <0 - this Orderable is less than other. 0 - this Orderable equals other. >0 - this Orderable is greater than other. The code should not explicitly look for -1, or 1.

  Throws:

  StandardException - Thrown on error

• compare

  int compare​(DataValueDescriptor other,
              boolean nullsOrderedLow)
       throws StandardException

  Compare this Orderable with another, with configurable null ordering. This method treats nulls as ordered values, but allows the caller to specify whether they should be lower than all non-NULL values, or higher than all non-NULL values.

  Parameters:

  other - The Orderable to compare this one to. % @param nullsOrderedLow True if null should be lower than non-NULL

  Returns:

  <0 - this Orderable is less than other. 0 - this Orderable equals other. >0 - this Orderable is greater than other. The code should not explicitly look for -1, or 1.

  Throws:

  StandardException - Thrown on error

• compare

  boolean compare​(int op,
                  DataValueDescriptor other,
                  boolean orderedNulls,
                  boolean unknownRV)
           throws StandardException

  Compare this Orderable with a given Orderable for the purpose of qualification and sorting. The caller gets to determine how nulls should be treated - they can either be ordered values or unknown values.

  Parameters:

  op - Orderable.ORDER_OP_EQUALS means do an = comparison. Orderable.ORDER_OP_LESSTHAN means compare this < other. Orderable.ORDER_OP_LESSOREQUALS means compare this <= other.

  other - The DataValueDescriptor to compare this one to.

  orderedNulls - True means to treat nulls as ordered values, that is, treat SQL null as equal to null, and less than all other values. False means to treat nulls as unknown values, that is, the result of any comparison with a null is the UNKNOWN truth value.

  unknownRV - The return value to use if the result of the comparison is the UNKNOWN truth value. In other words, if orderedNulls is false, and a null is involved in the comparison, return unknownRV. This parameter is not used orderedNulls is true.

  Returns:

  true if the comparison is true (duh!)

  Throws:

  StandardException - Thrown on error

• compare

  boolean compare​(int op,
                  DataValueDescriptor other,
                  boolean orderedNulls,
                  boolean nullsOrderedLow,
                  boolean unknownRV)
           throws StandardException

  Compare this Orderable with another, with configurable null ordering. The caller gets to determine how nulls should be treated - they can either be ordered values or unknown values. The caller also gets to decide, if they are ordered, whether they should be lower than non-NULL values, or higher

  Parameters:

  op - Orderable.ORDER_OP_EQUALS means do an = comparison. Orderable.ORDER_OP_LESSTHAN means compare this < other. Orderable.ORDER_OP_LESSOREQUALS means compare this <= other.

  other - The DataValueDescriptor to compare this one to.

  orderedNulls - True means to treat nulls as ordered values, that is, treat SQL null as equal to null, and either greater or less than all other values. False means to treat nulls as unknown values, that is, the result of any comparison with a null is the UNKNOWN truth value.

  nullsOrderedLow - True means NULL less than non-NULL, false means NULL greater than non-NULL. Only relevant if orderedNulls is true.

  unknownRV - The return value to use if the result of the comparison is the UNKNOWN truth value. In other words, if orderedNulls is false, and a null is involved in the comparison, return unknownRV. This parameter is not used orderedNulls is true.

  Returns:

  true if the comparison is true (duh!)

  Throws:

  StandardException - Thrown on error

• setValue

  void setValue​(java.io.InputStream theStream,
                int valueLength)
         throws StandardException

  Set the value to be the contents of the stream.

  The reading of the stream may be delayed until execution time, and the format of the stream is required to be the format of this type.

  Note that the logical length excludes any header bytes and marker bytes (for instance the Derby specific EOF stream marker). Specifying the logical length may improve performance in some cases, but specifying that the length is unknown (UNKNOWN_LOGICAL_LENGTH should always leave the system in a functional state. Specifying an incorrect length will cause errors.

  Parameters:

  theStream - stream of correctly formatted data

  valueLength - logical length of the stream's value in units of this type (e.g. chars for string types), or UNKNOWN_LOGICAL_LENGTH if the logical length is unknown

  Throws:

  StandardException

• checkHostVariable

  void checkHostVariable​(int declaredLength)
                  throws StandardException

  Check the value to seem if it conforms to the restrictions imposed by DB2/JCC on host variables for this type.

  Throws:

  StandardException - Variable is too big.

• estimateMemoryUsage

  int estimateMemoryUsage()

  Estimate the memory usage in bytes of the data value and the overhead of the class.

  Returns:

  the estimated memory usage