QueryableDatatype (DBvolution 7 0.9.13-SNAPSHOT API)

java.lang.Object
- nz.co.gregs.dbvolution.datatypes.QueryableDatatype<T>

Type Parameters:
T -

All Implemented Interfaces:

Serializable, DBExpression

Direct Known Subclasses:

DBBoolean, DBBooleanArray, DBDate, DBDateRepeat, DBEnum, DBInteger, DBLargeObject, DBLine2D, DBLineSegment2D, DBMultiPoint2D, DBNumber, DBPoint2D, DBPolygon2D, DBString, DBUnknownDatatype, DBUntypedValue
```
public abstract class QueryableDatatype<T>
extends Object
implements Serializable, DBExpression
```
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Author:

Gregory Graham

See Also:
Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static Boolean`	`SORT_ASCENDING` Used to indicate the the QDT should be sorted so that the values run from A->Z or 0->9 when using the `setSortOrder(java.lang.Boolean)` method.
`static Boolean`	`SORT_DESCENDING` Used to indicate the the QDT should be sorted so that the values run from Z->A or 9->0 when using the `setSortOrder(java.lang.Boolean)` method.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`QueryableDatatype()` Default Constructor
`protected`	`QueryableDatatype(DBExpression columnExpression)` Create a QDT with a permanent column expression.
`protected`	`QueryableDatatype(DBExpression[] columnExpression)` Create a QDT with a permanent column expression.
`protected`	`QueryableDatatype(T obj)` Create a QueryableDatatype with the exact value provided.

Method Summary

Methods
Modifier and Type	Method and Description
`QueryableDatatype<T>`	`clear()` Remove the conditions, criteria, and operators applied to this QDT.
`QueryableDatatype<T>`	`copy()` Copies a QueryableDatatype and returns the copy.
`String`	`createSQLForFromClause(DBDatabase database)`
`boolean`	`equals(Object otherObject)`
`String`	`formatColumnForSQLStatement(DBDefinition db, String formattedColumnName)` Returns the column of the object formatted for the database.
`protected abstract String`	`formatValueForSQLStatement(DBDefinition db)` Returns the value of the object formatted for the database This should be overridden in each subclass This method is called by toSQLString after checking for NULLs and should return a string representation of the object formatted for use within a SQL select, insert, update, or delete statement.
`abstract ColumnProvider`	`getColumn(RowDefinition row)` Creates a Column Provider suitable to this QDT.
`DBExpression[]`	`getColumnExpression()` Returns the expression underlying this QDT or null.
`protected abstract T`	`getFromResultSet(DBDefinition database, ResultSet resultSet, String fullColumnName)` Returns the correct object from the ResultSet for the QueryableDatatype to handle.
`protected T`	`getLiteralValue()` Support DBvolution at Patreon
`DBOperator`	`getOperator()` Support DBvolution at Patreon
`String`	`getPreviousSQLValue(DBDefinition db)` Returns the previous value of this field as an SQL formatted String.
`protected QueryableDatatype<T>`	`getPreviousValue()` Used internally.
`protected PropertyWrapperDefinition`	`getPropertyWrapperDefinition()` Used internally.
`QueryableDatatype<T>`	`getQueryableDatatypeForExpressionValue()` Provides a blank instance of the `QueryableDatatype` used by this expression.
`static <S> QueryableDatatype<S>`	`getQueryableDatatypeForObject(S o)` Returns an appropriate QueryableDatatype for the provided object.
`static <T extends QueryableDatatype<?>> T`	`getQueryableDatatypeInstance(Class<T> requiredQueryableDatatype)` Factory method that creates a new QDT instance with the same class as the provided example.
`Boolean`	`getSortOrder()` Return the order in which this QDT will be sorted.
`abstract String`	`getSQLDatatype()` Provides the SQL datatype used by default for this type of object.
`Set<DBRow>`	`getTablesInvolved()` Returns a Set of the DBRow instances involved in this expression.
`Object`	`getValue()` Gets the current literal value of this queryable data type.
`boolean`	`hasBeenSet()` Support DBvolution at Patreon
`boolean`	`hasChanged()` Indicates that the value of this QDT has been changed from its defined value.
`boolean`	`hasColumnExpression()` Tests for the expression underlying this QDT or returns FALSE.
`int`	`hashCode()`
`void`	`includingNulls()` Causes the underlying operator to explicitly include NULL values in it's processing.
`boolean`	`isComplexExpression()`
`boolean`	`isDefined()` Support DBvolution at Patreon
`boolean`	`isNotNull()` Indicates whether object is NULL within the database
`boolean`	`isNull()` Indicates whether object is NULL within the database
`boolean`	`isPurelyFunctional()` Indicates whether or not the expression includes table columns.
`void`	`negateOperator()` Negate the meaning of the comparison associated with this object.
`QueryableDatatype<T>`	`removeConstraints()` Remove the conditions, criteria, and operators applied to this QDT.
`protected void`	`setChanged(boolean hasChanged)` Used internally.
`protected void`	`setColumnExpression(DBExpression... columnExpression)` Used Internally.
`protected void`	`setDefined(boolean defined)`
`void`	`setFromResultSet(DBDefinition defn, ResultSet resultSet, String resultSetColumnName)` Used internally to set the QDT to the value returned from the database.
`protected void`	`setLiteralValue(T newLiteralValue)` Sets the literal value of this queryable data type.
`void`	`setOperator(DBOperator operator)`
`protected void`	`setPreviousValue(QueryableDatatype<T> queryableDatatype)` Used internally.
`QueryableDatatype<T>`	`setSortOrderAscending()` Used to switch the direction of the column's sort order Support DBvolution at Patreon
`QueryableDatatype<T>`	`setSortOrderDescending()` Used to switch the direction of the column's sort order Support DBvolution at Patreon
`protected DBOperator`	`setToNull()` Sets the value of this column to DBNull Also changes the operator to DBIsNullOperator for comparisons Support DBvolution at Patreon
`protected DBOperator`	`setToNull(DBDefinition database)` Used during setFromResultSet to set the QDT to a database NULL value.
`void`	`setUnchanged()` Clear the changes to this QDT and remove the previous value as though this QDT had never had any value other than the current value.
`protected abstract void`	`setValueFromStandardStringEncoding(String encodedValue)` Set the value of this QDT to the value provided from the standard string encoding of this datatype
`void`	`setValueToNull()` Convenient synonym for setValue(null).
`String`	`stringValue()` Returns the raw value as a String
`String`	`toSQLString(DBDefinition defn)` Formats the literal value for use within an SQL statement.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface nz.co.gregs.dbvolution.expressions.DBExpression
isAggregator

- Field Detail
  - SORT_ASCENDING
```
public static final Boolean SORT_ASCENDING
```
    Used to indicate the the QDT should be sorted so that the values run from A->Z or 0->9 when using the setSortOrder(java.lang.Boolean) method.
  - SORT_DESCENDING
```
public static final Boolean SORT_DESCENDING
```
    Used to indicate the the QDT should be sorted so that the values run from Z->A or 9->0 when using the setSortOrder(java.lang.Boolean) method.
- Constructor Detail
  - QueryableDatatype
```
protected QueryableDatatype()
```
    Default Constructor
  - QueryableDatatype
```
protected QueryableDatatype(T obj)
```
    Create a QueryableDatatype with the exact value provided.
    Equivalent to new QueryableDatatype().setValue(obj);
    
    Parameters:
    obj - the literal value of the QDT.
  - QueryableDatatype
```
protected QueryableDatatype(DBExpression[] columnExpression)
```
    Create a QDT with a permanent column expression.
    Use this method within a DBRow sub-class to create a column that uses an expression to create the value at query time.
    This is particularly useful for trimming strings or converting between types but also allows for complex arithmetic and transformations.
    
    Parameters:
    columnExpression - columnExpression
  - QueryableDatatype
```
protected QueryableDatatype(DBExpression columnExpression)
```
    Create a QDT with a permanent column expression.
    Use this method within a DBRow sub-class to create a column that uses an expression to create the value at query time.
    This is particularly useful for trimming strings or converting between types but also allows for complex arithmetic and transformations.
    
    Parameters:
    columnExpression - columnExpression
- Method Detail
  - getQueryableDatatypeInstance
```
public static <T extends QueryableDatatype<?>> T getQueryableDatatypeInstance(Class<T> requiredQueryableDatatype)
```
    Factory method that creates a new QDT instance with the same class as the provided example.
    This method only provides a new blank instance. To copy the QDT and its fields, use copy().
    
    Type Parameters:
    T - the QDT type
    Parameters:
    requiredQueryableDatatype - requiredQueryableDatatype
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    Returns:
    a new instance of the supplied QDT class
  - getQueryableDatatypeForObject
```
public static <S> QueryableDatatype<S> getQueryableDatatypeForObject(S o)
```
    Returns an appropriate QueryableDatatype for the provided object.
    Provides the base QDTs for Integer, Number, String, Date, Byte[], Boolean, NumberResult, StringResult, DateResult, LargeObjectResult, BooleanResult and defaults everything else to DBJavaObject.
    
    Type Parameters:
    S - the base datatype returned by the QDT
    Parameters:
    o - the object to be encapsulated in the QDT
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    Returns:
    a QDT that will provide good results for the provided object.
  - copy
```
public QueryableDatatype<T> copy()
```
    Copies a QueryableDatatype and returns the copy. Used internally to provide immutability to DBOperator objects. The intention is that this method will provide a snapshot of the QDT at this moment in time and copy or clone any internal objects that might change. Subclasses should extend this method if they have fields that maintain the state of the QDT. Always use the super.copy() method first when overriding this method.
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    Specified by:
    
    copy in interface DBExpression
    
    Returns:
    a complete copy of the QDT with all values set.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - stringValue
```
public String stringValue()
```
    Returns the raw value as a String
    A database NULL is treated as an empty string, use isNull() to handle NULLs separately.
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    Returns:
    the literal value as a String
  - removeConstraints
```
public QueryableDatatype<T> removeConstraints()
```
    Remove the conditions, criteria, and operators applied to this QDT.
    After calling this method, this object will not cause a where clause to be generated in any subsequent queries.
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    Returns:
    this instance.
  - negateOperator
```
public void negateOperator()
```
    Negate the meaning of the comparison associated with this object.
    For instance, given thisQDT.permittedValue(1), thisQDT.negateOperator() will cause the operator to return everything other than 1.
    If this object has an operator defined for it, this method will invert the meaning of the operator by calling the operator's DBOperator.invertOperator(java.lang.Boolean) with "true".
  - getValue
```
public Object getValue()
```
    Gets the current literal value of this queryable data type. The returned value should be in the correct type as appropriate for the type of queryable data type.
    This method will return NULL if the QDT represents a database NULL OR the field is undefined. Use isNull() and isDefined() to differentiate the 2 states.
    Undefined QDTs represents a QDT that is not a field from the database. Undefined QDTs are similar to undefined DBRows
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    Returns:
    the literal value, if defined, which may be null
  - setValueFromStandardStringEncoding
```
protected abstract void setValueFromStandardStringEncoding(String encodedValue)
```
    Set the value of this QDT to the value provided from the standard string encoding of this datatype
    Subclass writers should ensure that the method handles nulls correctly and throws an exception if an inappropriate value is supplied.
    
    Parameters:
    encodedValue - the value of the QDT in the appropriate encoding
  - setLiteralValue
```
protected void setLiteralValue(T newLiteralValue)
```
    Sets the literal value of this queryable data type. Replaces any assigned operator with an equals operator on the given value.
    
    Parameters:
    newLiteralValue - the literalValue to set
  - setUnchanged
```
public void setUnchanged()
```
    Clear the changes to this QDT and remove the previous value as though this QDT had never had any value other than the current value.
  - setToNull
```
protected DBOperator setToNull()
```
    Sets the value of this column to DBNull Also changes the operator to DBIsNullOperator for comparisons
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    Returns:
    the DBOperator that will be used with this QDT
  - includingNulls
```
public void includingNulls()
```
    Causes the underlying operator to explicitly include NULL values in it's processing.
    For instance: normally thisQDT.permittedValue(1) will only return fields with the value 1. Calling thisQDT.includingNulls() as well will cause the operator to return fields with value 1 and those with value NULL.
  - getSQLDatatype
```
public abstract String getSQLDatatype()
```
    Provides the SQL datatype used by default for this type of object.
    This should be overridden in each subclass
    
    Example return value: "VARCHAR(1000)"
    
    Database specific datatypes are provided by the DBDefinition in the method DBDefinition.getDatabaseDataTypeOfQueryableDatatype(nz.co.gregs.dbvolution.datatypes.QueryableDatatype<?>)
    
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    Returns:
    the standard SQL datatype that corresponds to this QDT as a String
  - toSQLString
```
public final String toSQLString(DBDefinition defn)
```
    Formats the literal value for use within an SQL statement.
    This is used internally to transform the Java object in to SQL format. You won't need to use it.
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    Specified by:
    
    toSQLString in interface DBExpression
    
    Parameters:
    defn -
    
    Returns:
    the literal value as it would appear in an SQL statement i.e. {yada} => 'yada', {1} => 1 and {} => NULL
  - formatValueForSQLStatement
```
protected abstract String formatValueForSQLStatement(DBDefinition db)
```
    Returns the value of the object formatted for the database This should be overridden in each subclass This method is called by toSQLString after checking for NULLs and should return a string representation of the object formatted for use within a SQL select, insert, update, or delete statement. For Example: DBString{yada} => 'yada' DBInteger{1234} => 123 DBDate{1/March/2013} => TO_DATE('20130301', 'YYYYMMDD')
    
    Parameters:
    db - db
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    Returns:
    the literal value translated to a String ready to insert into an SQL statement
  - getOperator
```
public DBOperator getOperator()
```
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    Returns:
    the operator
  - setOperator
```
public void setOperator(DBOperator operator)
```
    Parameters:
    operator - the operator to set
  - hasChanged
```
public boolean hasChanged()
```
    Indicates that the value of this QDT has been changed from its defined value.
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    Returns:
    TRUE if the set value of this QDT has been changed since it was retrieved or updated, otherwise FALSE.
  - setFromResultSet
```
public void setFromResultSet(DBDefinition defn,
                    ResultSet resultSet,
                    String resultSetColumnName)
                      throws SQLException
```
    Used internally to set the QDT to the value returned from the database.
    If you create a new QDT you should override this method. The default implementation in QueryableDatatype processes the ResultSet column as a String. You should follow the basic pattern but change ResultSet.getString(String) to the required ResultSet method and add any required post-processing.
    Note that most of the method is dedicated to detecting NULL values. This is very important as are the calls to setUnchanged() and setDefined(boolean)
    
    Parameters:
    defn - database
    resultSet - resultSet
    resultSetColumnName - resultSetColumnName
    
    Throws:
    
    SQLException - Database exceptions may be thrown
  - getFromResultSet
```
protected abstract T getFromResultSet(DBDefinition database,
                 ResultSet resultSet,
                 String fullColumnName)
                               throws SQLException
```
    Returns the correct object from the ResultSet for the QueryableDatatype to handle.
    
    Parameters:
    database - database
    resultSet - resultSet
    fullColumnName - fullColumnName
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    Returns:
    the expected object from the ResultSet. 1 Database exceptions may be thrown
    
    Throws:
    
    SQLException - java.sql.SQLException
  - isNull
```
public boolean isNull()
```
    Indicates whether object is NULL within the database
    Databases and Java both use the term NULL but for slightly different meanings.
    This method indicates whether the field represented by this object is NULL in the database sense.
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    Returns:
    TRUE if this object represents a NULL database value, otherwise FALSE
  - isNotNull
```
public boolean isNotNull()
```
    Indicates whether object is NULL within the database
    Databases and Java both use the term NULL but for slightly different meanings.
    This method indicates whether the field represented by this object is NULL in the database sense.
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    Returns:
    TRUE if this object represents a NULL database value, otherwise FALSE
  - getPreviousSQLValue
```
public String getPreviousSQLValue(DBDefinition db)
```
    Returns the previous value of this field as an SQL formatted String.
    Used by DBActionList to generate revert action lists.
    
    Parameters:
    db - db
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    Returns:
    the previous value of this field as an SQL formatted String
  - setSortOrderAscending
```
public QueryableDatatype<T> setSortOrderAscending()
```
    Used to switch the direction of the column's sort order
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    Returns:
    this object
  - setSortOrderDescending
```
public QueryableDatatype<T> setSortOrderDescending()
```
    Used to switch the direction of the column's sort order
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    Returns:
    this object
  - getSortOrder
```
public Boolean getSortOrder()
```
    Return the order in which this QDT will be sorted.
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    Returns:
    SORT_ASCENDING if the column is to be sorted ascending, SORT_DESCENDING otherwise.
  - clear
```
public QueryableDatatype<T> clear()
```
    Remove the conditions, criteria, and operators applied to this QDT.
    After calling this method, this object will not cause a where clause to be generated in any subsequent queries.
    Synonym for removeConstraints().
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    Returns:
    this instance
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object otherObject)
```
    Overrides:
    
    equals in class Object
  - isDefined
```
public boolean isDefined()
```
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    Returns:
    the undefined
  - setDefined
```
protected void setDefined(boolean defined)
```
    Parameters:
    defined - the undefined to set
  - getQueryableDatatypeForExpressionValue
```
public QueryableDatatype<T> getQueryableDatatypeForExpressionValue()
```
    Description copied from interface: DBExpression
    
    Provides a blank instance of the QueryableDatatype used by this expression.
    You are probably looking for ExpressionColumn.asExpressionColumn().
    Note that this method is not good for use in everyday DBvolution code and should probably be reserved for meta-programming.
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    Specified by:
    
    getQueryableDatatypeForExpressionValue in interface DBExpression
    
    Returns:
    the QueryableDatatype subclass that corresponds to the results of this expression
  - getColumnExpression
```
public final DBExpression[] getColumnExpression()
```
    Returns the expression underlying this QDT or null.
    When the QDT is created using an expression , this method makes the expression accessible.
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    Returns:
    the underlying expression if there is one, or NULL otherwise.
  - hasColumnExpression
```
public final boolean hasColumnExpression()
```
    Tests for the expression underlying this QDT or returns FALSE.
    When the QDT is created using an expression , this method makes the expression accessible.
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    Returns:
    TRUE if there is a underlying expression, or FALSE otherwise.
  - getTablesInvolved
```
public Set<DBRow> getTablesInvolved()
```
    Description copied from interface: DBExpression
    
    Returns a Set of the DBRow instances involved in this expression.
    Used by QueryGraph to plot the connections between tables and avoid cartesian joins.
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    Specified by:
    
    getTablesInvolved in interface DBExpression
    
    Returns:
    a set of DBRow instances involved in this DBExpression.
  - hasBeenSet
```
public boolean hasBeenSet()
```
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    Returns:
    the setValueHasBeenCalled
  - getLiteralValue
```
protected T getLiteralValue()
```
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    Returns:
    the literalValue
  - setToNull
```
protected DBOperator setToNull(DBDefinition database)
```
    Used during setFromResultSet to set the QDT to a database NULL value.
    DBDatabase is supplied so that database-specific processing, such as Oracle empty strings, can be performed.
    Sets the value of this column to DBNull Also changes the operator to DBIsNullOperator for comparisons.
    The default implementation just calls setToNull()
    
    Parameters:
    database - database
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    Returns:
    the DBOperator that will be used with this QDT
  - setChanged
```
protected void setChanged(boolean hasChanged)
```
    Used internally.
    
    Parameters:
    hasChanged - hasChanged
  - getPreviousValue
```
protected QueryableDatatype<T> getPreviousValue()
```
    Used internally.
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    Returns:
    the previous value of this QDT.
  - setPreviousValue
```
protected void setPreviousValue(QueryableDatatype<T> queryableDatatype)
```
    Used internally.
    
    Parameters:
    queryableDatatype - queryableDatatype
  - getPropertyWrapperDefinition
```
protected PropertyWrapperDefinition getPropertyWrapperDefinition()
```
    Used internally.
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    Returns:
    the PropertyWrapperDefinition
  - setColumnExpression
```
protected final void setColumnExpression(DBExpression... columnExpression)
```
    Used Internally.
    
    Parameters:
    columnExpression - the columnExpression to set
  - setValueToNull
```
public void setValueToNull()
```
    Convenient synonym for setValue(null).
  - isPurelyFunctional
```
public boolean isPurelyFunctional()
```
    Description copied from interface: DBExpression
    
    Indicates whether or not the expression includes table columns.
    Purely functional expressions use only in-built functions or literal values to produce results and do not require data from tables.
    Some databases, notably MS SQLServer, can not group purely functional expressions.
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    Specified by:
    
    isPurelyFunctional in interface DBExpression
    
    Returns:
    TRUE if the expression does not access table data, otherwise FALSE.
  - formatColumnForSQLStatement
```
public String formatColumnForSQLStatement(DBDefinition db,
                                 String formattedColumnName)
```
    Returns the column of the object formatted for the database.
    This method provides a route to transforming all calls to a column prior to use in SQL.
    
    See the implementation in DBStringTrimmed for an example.
    
    Parameters:
    db - db
    formattedColumnName - the name of the database column or similar expression ready to be used in an SQL excerpt
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    Returns:
    the formatted column ready to be used in an SQL statement
  - getColumn
```
public abstract ColumnProvider getColumn(RowDefinition row)
                                  throws IncorrectRowProviderInstanceSuppliedException
```
    Creates a Column Provider suitable to this QDT.
    Creates a ColumnProvider object of the correct type for this QueryableDatatype, using this object and the provided row.
    
    Used internally to maintain the relationship between QDTs and their ColumnProvider equivalents.
    
    Parameters:
    row -
    
    Returns:
    a column object appropriate to this datatype based on the object and the row
    
    Throws:
    
    IncorrectRowProviderInstanceSuppliedException - if this object is not a field in the row.
  - createSQLForFromClause
```
public final String createSQLForFromClause(DBDatabase database)
```
    Specified by:
    
    createSQLForFromClause in interface DBExpression
  - isComplexExpression
```
public final boolean isComplexExpression()
```
    Specified by:
    
    isComplexExpression in interface DBExpression

Class QueryableDatatype<T>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface nz.co.gregs.dbvolution.expressions.DBExpression

Field Detail

SORT_ASCENDING

SORT_DESCENDING

Constructor Detail

QueryableDatatype

QueryableDatatype

QueryableDatatype

QueryableDatatype

Method Detail

getQueryableDatatypeInstance

getQueryableDatatypeForObject

copy

toString

stringValue

removeConstraints

negateOperator

getValue

setValueFromStandardStringEncoding

setLiteralValue

setUnchanged

setToNull

includingNulls

getSQLDatatype

toSQLString

formatValueForSQLStatement

getOperator

setOperator

hasChanged

setFromResultSet

getFromResultSet

isNull

isNotNull

getPreviousSQLValue

setSortOrderAscending

setSortOrderDescending

getSortOrder

clear

hashCode

equals

isDefined

setDefined

getQueryableDatatypeForExpressionValue

getColumnExpression

hasColumnExpression

getTablesInvolved

hasBeenSet

getLiteralValue

setToNull

setChanged

getPreviousValue

setPreviousValue

getPropertyWrapperDefinition

setColumnExpression

setValueToNull

isPurelyFunctional

formatColumnForSQLStatement

getColumn

createSQLForFromClause

isComplexExpression