DataColumn
Inheritance: java.lang.Object
public final class DataColumn
Represents the schema of a column in a DataTable.
Constructors
| Constructor | Description |
|---|---|
| DataColumn() | Initializes a new instance of a DataColumn class as type string. |
| DataColumn(String columnName) | Inititalizes a new instance of the DataColumn class, as type string, using the specified column name. |
| DataColumn(String name, DataTable table) | Initializes a new instance of the @{link DataColumn} class using the specified column name and table it belongs to. |
| DataColumn(String columnName, Class dataType) | Inititalizes a new instance of the DataColumn class using the specified column name and data type. |
| DataColumn(String name, Class type, DataTable table) | Initializes a new instance of the DataColumn class using the specified column name, data type and data table it belongs to. |
Methods
| Method | Description |
|---|---|
| getColumnName() | Gets the name of the column in the DataColumnCollection. |
| setColumnName(String value) | Sets the name of the column in the DataColumnCollection. |
| getAllowDBNull() | Gets a value that indicates whether null values are allowed in this column for rows that belong to the table. |
| setAllowDBNull(boolean value) | Sets a value that indicates whether null values are allowed in this column for rows that belong to the table. |
| getDataType() | Gets the type of data stored in the column. |
| setDataType(Class value) | Sets the type of data stored in the column. |
| setDefaultValue(Object value) | Sets the default value for the column when you are creating new rows. |
| getDefaultValue() | Gets the default value for the column when you are creating new rows. |
| getOrdinal() | Gets the position of the column in the DataColumnCollection collection. |
| setOrdinal(int ordinal) | Changes the ordinal or position of the DataColumn to the specified ordinal or position. |
| getColumnMapping() | Gets the MappingType of the column. |
| setColumnMapping(int value) | Sets the MappingType of the column. |
| getNamespace() | Gets the namespace of the DataColumn. |
| setNamespace(String value) | Sets the namespace of the DataColumn. |
| getPrefix() | Gets an XML prefix that aliases the namespace of the DataTable. |
| setPrefix(String value) | Sets an XML prefix that aliases the namespace of the DataTable. |
| getTable() | Gets the DataTable to which the column belongs to. |
| getAutoIncrement() | Gets a value that indicates whether the column automatically increments the value of the column for new rows added to the table. |
| setAutoIncrement(boolean value) | Sets a value that indicates whether the column automatically increments the value of the column for new rows added to the table. |
| setMaxLength(int value) | Sets the maximum length of a text column. |
| getMaxLength() | Gets the maximum length of a text column. |
| getCaption() | Gets the caption for the column. |
| setCaption(String value) | Sets the caption for the column. |
| getAutoIncrementSeed() | Gets the starting value for a column that has its getAutoIncrement() / setAutoIncrement(boolean) property set to true. |
| setAutoIncrementSeed(long value) | Sets the starting value for a column that has its getAutoIncrement() / setAutoIncrement(boolean) property set to true. |
| getAutoIncrementStep() | Gets the increment used by a column with its getAutoIncrement() / setAutoIncrement(boolean) property set to true. |
| setAutoIncrementStep(long value) | Sets the increment used by a column with its getAutoIncrement() / setAutoIncrement(boolean) property set to true. |
| setReadOnly(boolean value) | Sets a value that indicates whether the column allows for changes as soon as a row has been added to the table. |
| isReadOnly() | |
| getReadOnly() | Gets a value that indicates whether the column allows for changes as soon as a row has been added to the table. |
| getUnique() | Gets a value that indicates whether the values in each row of the column must be unique. |
| isUnique() | |
| setUnique(boolean value) | Sets a value that indicates whether the values in each row of the column must be unique. |
| getExpression() | Gets the expression used to filter rows, calculate the values in a column, or create an aggregate column. |
| areColumnSetsTheSame(DataColumn[] columnSet, DataColumn[] compareSet) | |
| toString() | Gets the getExpression() of the column, if one exists. |
DataColumn()
public DataColumn()
Initializes a new instance of a DataColumn class as type string.
DataColumn(String columnName)
public DataColumn(String columnName)
Inititalizes a new instance of the DataColumn class, as type string, using the specified column name.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| columnName | java.lang.String | A string that represents the name of the column to be created. If set to null or an empty string (""), a default name will be specified when added to the columns collection. |
DataColumn(String name, DataTable table)
public DataColumn(String name, DataTable table)
Initializes a new instance of the @{link DataColumn} class using the specified column name and table it belongs to.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| name | java.lang.String | name of the DataColumn |
| table | DataTable | the table this column belongs to |
DataColumn(String columnName, Class dataType)
public DataColumn(String columnName, Class dataType)
Inititalizes a new instance of the DataColumn class using the specified column name and data type.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| columnName | java.lang.String | A string that represents the name of the column to be created. If set to null or an empty string (""), a default name will be specified when added to the columns collection. |
| dataType | java.lang.Class | A supported getDataType() / setDataType(java.lang.Class). |
DataColumn(String name, Class type, DataTable table)
public DataColumn(String name, Class type, DataTable table)
Initializes a new instance of the DataColumn class using the specified column name, data type and data table it belongs to.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| name | java.lang.String | name of the DataColumn |
| type | java.lang.Class | data type |
| table | DataTable | the table this column belongs to |
getColumnName()
public final String getColumnName()
Gets the name of the column in the DataColumnCollection.
Returns: java.lang.String - The name of the column.
setColumnName(String value)
public final void setColumnName(String value)
Sets the name of the column in the DataColumnCollection.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | java.lang.String | The name of the column. |
getAllowDBNull()
public final boolean getAllowDBNull()
Gets a value that indicates whether null values are allowed in this column for rows that belong to the table.
Returns: boolean - true if null values values are allowed; otherwise, false. The default is true.
setAllowDBNull(boolean value)
public final void setAllowDBNull(boolean value)
Sets a value that indicates whether null values are allowed in this column for rows that belong to the table.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | boolean | true if null values values are allowed; otherwise, false. The default is true. |
getDataType()
public final Class getDataType()
Gets the type of data stored in the column.
Returns: java.lang.Class - A java.lang.Class object that represents the column data type.
setDataType(Class value)
public final void setDataType(Class value)
Sets the type of data stored in the column.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | java.lang.Class | A java.lang.Class object that represents the column data type. |
setDefaultValue(Object value)
public final void setDefaultValue(Object value)
Sets the default value for the column when you are creating new rows.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | java.lang.Object | A value appropriate to the column’s getDataType() / setDataType(java.lang.Class). |
getDefaultValue()
public final Object getDefaultValue()
Gets the default value for the column when you are creating new rows.
Returns: java.lang.Object - A value appropriate to the column’s getDataType() / setDataType(java.lang.Class).
getOrdinal()
public final int getOrdinal()
Gets the position of the column in the DataColumnCollection collection.
Returns: int - The position of the column. Gets -1 if the column is not a member of a collection.
setOrdinal(int ordinal)
public final void setOrdinal(int ordinal)
Changes the ordinal or position of the DataColumn to the specified ordinal or position.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| ordinal | int | The specified ordinal. |
getColumnMapping()
public final int getColumnMapping()
Gets the MappingType of the column.
Returns: int - One of the MappingType values. The returned value is one of MappingType constants.
setColumnMapping(int value)
public final void setColumnMapping(int value)
Sets the MappingType of the column.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | int | One of the MappingType values. The value must be one of MappingType constants. |
getNamespace()
public final String getNamespace()
Gets the namespace of the DataColumn.
Returns: java.lang.String - The namespace of the DataColumn.
setNamespace(String value)
public final void setNamespace(String value)
Sets the namespace of the DataColumn.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | java.lang.String | The namespace of the DataColumn. |
getPrefix()
public final String getPrefix()
Gets an XML prefix that aliases the namespace of the DataTable.
Returns: java.lang.String - The XML prefix for the DataTable namespace.
setPrefix(String value)
public final void setPrefix(String value)
Sets an XML prefix that aliases the namespace of the DataTable.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | java.lang.String | The XML prefix for the DataTable namespace. |
getTable()
public final DataTable getTable()
Gets the DataTable to which the column belongs to.
Returns: DataTable - The DataTable that the DataColumn belongs to.
getAutoIncrement()
public final boolean getAutoIncrement()
Gets a value that indicates whether the column automatically increments the value of the column for new rows added to the table.
Returns: boolean - true if the value of the column increments automatically; otherwise, false. The default is false.
setAutoIncrement(boolean value)
public final void setAutoIncrement(boolean value)
Sets a value that indicates whether the column automatically increments the value of the column for new rows added to the table.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | boolean | true if the value of the column increments automatically; otherwise, false. The default is false. |
setMaxLength(int value)
public final void setMaxLength(int value)
Sets the maximum length of a text column.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | int | The maximum length of the column in characters. If the column has no maximum length, the value is -1 (default). |
getMaxLength()
public final int getMaxLength()
Gets the maximum length of a text column.
Returns: int - The maximum length of the column in characters. If the column has no maximum length, the value is -1 (default).
getCaption()
public final String getCaption()
Gets the caption for the column.
Returns: java.lang.String - The caption of the column. If not set, returns the getColumnName() / setColumnName(java.lang.String) value.
setCaption(String value)
public final void setCaption(String value)
Sets the caption for the column.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | java.lang.String | The caption of the column. If not set, returns the getColumnName() / setColumnName(java.lang.String) value. |
getAutoIncrementSeed()
public final long getAutoIncrementSeed()
Gets the starting value for a column that has its getAutoIncrement() / setAutoIncrement(boolean) property set to true.
Returns: long - The starting value for the getAutoIncrement() / setAutoIncrement(boolean) feature.
setAutoIncrementSeed(long value)
public final void setAutoIncrementSeed(long value)
Sets the starting value for a column that has its getAutoIncrement() / setAutoIncrement(boolean) property set to true.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | long | The starting value for the getAutoIncrement() / setAutoIncrement(boolean) feature. |
getAutoIncrementStep()
public final long getAutoIncrementStep()
Gets the increment used by a column with its getAutoIncrement() / setAutoIncrement(boolean) property set to true.
Returns: long - The number by which the value of the column is automatically incremented. The default is 1.
setAutoIncrementStep(long value)
public final void setAutoIncrementStep(long value)
Sets the increment used by a column with its getAutoIncrement() / setAutoIncrement(boolean) property set to true.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | long | The number by which the value of the column is automatically incremented. The default is 1. |
setReadOnly(boolean value)
public final void setReadOnly(boolean value)
Sets a value that indicates whether the column allows for changes as soon as a row has been added to the table.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | boolean | true if the column is read only; otherwise, false. The default is false. |
isReadOnly()
public final boolean isReadOnly()
Returns: boolean
getReadOnly()
public final boolean getReadOnly()
Gets a value that indicates whether the column allows for changes as soon as a row has been added to the table.
Returns: boolean - true if the column is read only; otherwise, false. The default is false.
getUnique()
public final boolean getUnique()
Gets a value that indicates whether the values in each row of the column must be unique.
Returns: boolean - true if the value must be unique; otherwise, false. The default is false.
isUnique()
public final boolean isUnique()
Returns: boolean
setUnique(boolean value)
public final void setUnique(boolean value)
Sets a value that indicates whether the values in each row of the column must be unique.
Parameters:
| Parameter | Type | Description |
|---|---|---|
| value | boolean | true if the value must be unique; otherwise, false. The default is false. |
getExpression()
public final String getExpression()
Gets the expression used to filter rows, calculate the values in a column, or create an aggregate column.
Returns: java.lang.String - An expression to calculate the value of a column, or create an aggregate column. The return type of an expression is determined by the getDataType() / setDataType(java.lang.Class) of the column.
areColumnSetsTheSame(DataColumn[] columnSet, DataColumn[] compareSet)
public static boolean areColumnSetsTheSame(DataColumn[] columnSet, DataColumn[] compareSet)
Parameters:
| Parameter | Type | Description |
|---|---|---|
| columnSet | DataColumn[] | |
| compareSet | DataColumn[] |
Returns: boolean
toString()
public final String toString()
Gets the getExpression() of the column, if one exists.
Returns: java.lang.String - The getExpression() value, if the property is set; otherwise, the getColumnName() / setColumnName(java.lang.String) property.