Column

java.lang.Object
- org.h2.table.Column

public class Column
extends java.lang.Object

This class represents a column in a table.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`NOT_NULLABLE` This column is not nullable.
`static int`	`NULLABLE` This column is nullable.
`static int`	`NULLABLE_UNKNOWN` It is not know whether this column is nullable.
`static java.lang.String`	`ROWID` The name of the rowid pseudo column.

Constructor Summary

Constructors
Constructor and Description
`Column(java.lang.String name, int type)`
`Column(java.lang.String name, int type, long precision, int scale, int displaySize)`
`Column(java.lang.String name, int type, long precision, int scale, int displaySize, java.lang.String[] enumerators)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addCheckConstraint(Session session, Expression expr)` Add a check constraint expression to this column.
`Value`	`convert(Value v)` Convert a value to this column's type.
`Value`	`convert(Value v, Mode mode)` Convert a value to this column's type using the given `Mode`.
`void`	`convertAutoIncrementToSequence(Session session, Schema schema, int id, boolean temporary)` Convert the auto-increment flag to a sequence that is linked with this table.
`void`	`copy(Column source)` Copy the data of the source column into the current column.
`boolean`	`equals(java.lang.Object o)`
`Expression`	`getCheckConstraint(Session session, java.lang.String asColumnName)` Get the check constraint expression for this column if set.
`Column`	`getClone()`
`int`	`getColumnId()`
`java.lang.String`	`getComment()`
`java.lang.String`	`getCreateSQL()`
`java.lang.String`	`getCreateSQLWithoutName()`
`Expression`	`getDefaultExpression()`
`int`	`getDisplaySize()`
`java.lang.String[]`	`getEnumerators()`
`java.lang.String`	`getName()`
`Expression`	`getOnUpdateExpression()`
`java.lang.String`	`getOriginalSQL()`
`long`	`getPrecision()`
`int`	`getScale()`
`int`	`getSelectivity()` Get the selectivity of the column.
`Sequence`	`getSequence()`
`java.lang.String`	`getSQL()`
`Table`	`getTable()`
`int`	`getType()`
`boolean`	`getVisible()`
`int`	`hashCode()`
`boolean`	`isAutoIncrement()`
`boolean`	`isEnumerated()`
`boolean`	`isNullable()`
`boolean`	`isPrimaryKey()`
`boolean`	`isWideningConversion(Column newColumn)` Check whether the new column is of the same type and not more restricted than this column.
`void`	`prepareExpression(Session session)` Prepare all expressions of this column.
`void`	`removeCheckConstraint()` Remove the check constraint if there is one.
`void`	`rename(java.lang.String newName)` Rename the column.
`void`	`setAutoIncrement(boolean autoInc, long start, long increment)` Set the autoincrement flag and related properties of this column.
`void`	`setComment(java.lang.String comment)`
`void`	`setComputedExpression(Expression expression)` Set the default value in the form of a computed expression of other columns.
`void`	`setConvertNullToDefault(boolean convert)`
`void`	`setDefaultExpression(Session session, Expression defaultExpression)` Set the default expression.
`void`	`setEnumerators(java.lang.String[] enumerators)`
`void`	`setNullable(boolean b)`
`void`	`setOnUpdateExpression(Session session, Expression onUpdateExpression)` Set the on update expression.
`void`	`setOriginalSQL(java.lang.String original)`
`void`	`setPrecision(long p)`
`void`	`setPrimaryKey(boolean primaryKey)`
`void`	`setSelectivity(int selectivity)` Set the new selectivity of a column.
`void`	`setSequence(Sequence sequence)`
`void`	`setTable(Table table, int columnId)` Set the table and column id.
`void`	`setVisible(boolean b)`
`java.lang.String`	`toString()`
`Value`	`validateConvertUpdateSequence(Session session, Value value)` Validate the value, convert it if required, and update the sequence value if required.

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

- Field Detail
  - ROWID
```
public static final java.lang.String ROWID
```
    The name of the rowid pseudo column.
    
    See Also:
    
    Constant Field Values
  - NOT_NULLABLE
```
public static final int NOT_NULLABLE
```
    This column is not nullable.
    
    See Also:
    
    Constant Field Values
  - NULLABLE
```
public static final int NULLABLE
```
    This column is nullable.
    
    See Also:
    
    Constant Field Values
  - NULLABLE_UNKNOWN
```
public static final int NULLABLE_UNKNOWN
```
    It is not know whether this column is nullable.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Column
```
public Column(java.lang.String name,
              int type)
```
  - Column
```
public Column(java.lang.String name,
              int type,
              long precision,
              int scale,
              int displaySize)
```
  - Column
```
public Column(java.lang.String name,
              int type,
              long precision,
              int scale,
              int displaySize,
              java.lang.String[] enumerators)
```
- Method Detail
  - equals
```
public boolean equals(java.lang.Object o)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - isEnumerated
```
public boolean isEnumerated()
```
  - getClone
```
public Column getClone()
```
  - convert
```
public Value convert(Value v)
```
    Convert a value to this column's type.
    
    Parameters:
    
    v - the value
    
    Returns:
    
    the value
  - convert
```
public Value convert(Value v,
                     Mode mode)
```
    Convert a value to this column's type using the given Mode.
    Use this method in case the conversion is Mode-dependent.
    
    Parameters:
    
    v - the value
    
    mode - the database Mode to use
    
    Returns:
    
    the value
  - setComputedExpression
```
public void setComputedExpression(Expression expression)
```
    Set the default value in the form of a computed expression of other columns.
    
    Parameters:
    
    expression - the computed expression
  - setTable
```
public void setTable(Table table,
                     int columnId)
```
    Set the table and column id.
    
    Parameters:
    
    table - the table
    
    columnId - the column index
  - getTable
```
public Table getTable()
```
  - setDefaultExpression
```
public void setDefaultExpression(Session session,
                                 Expression defaultExpression)
```
    Set the default expression.
    
    Parameters:
    
    session - the session
    
    defaultExpression - the default expression
  - setOnUpdateExpression
```
public void setOnUpdateExpression(Session session,
                                  Expression onUpdateExpression)
```
    Set the on update expression.
    
    Parameters:
    
    session - the session
    
    onUpdateExpression - the on update expression
  - getColumnId
```
public int getColumnId()
```
  - getSQL
```
public java.lang.String getSQL()
```
  - getName
```
public java.lang.String getName()
```
  - getType
```
public int getType()
```
  - getPrecision
```
public long getPrecision()
```
  - setPrecision
```
public void setPrecision(long p)
```
  - getDisplaySize
```
public int getDisplaySize()
```
  - getScale
```
public int getScale()
```
  - setNullable
```
public void setNullable(boolean b)
```
  - getEnumerators
```
public java.lang.String[] getEnumerators()
```
  - setEnumerators
```
public void setEnumerators(java.lang.String[] enumerators)
```
  - getVisible
```
public boolean getVisible()
```
  - setVisible
```
public void setVisible(boolean b)
```
  - validateConvertUpdateSequence
```
public Value validateConvertUpdateSequence(Session session,
                                           Value value)
```
    Validate the value, convert it if required, and update the sequence value if required. If the value is null, the default value (NULL if no default is set) is returned. Check constraints are validated as well.
    
    Parameters:
    
    session - the session
    
    value - the value or null
    
    Returns:
    
    the new or converted value
  - convertAutoIncrementToSequence
```
public void convertAutoIncrementToSequence(Session session,
                                           Schema schema,
                                           int id,
                                           boolean temporary)
```
    Convert the auto-increment flag to a sequence that is linked with this table.
    
    Parameters:
    
    session - the session
    
    schema - the schema where the sequence should be generated
    
    id - the object id
    
    temporary - true if the sequence is temporary and does not need to be stored
  - prepareExpression
```
public void prepareExpression(Session session)
```
    Prepare all expressions of this column.
    
    Parameters:
    
    session - the session
  - getCreateSQLWithoutName
```
public java.lang.String getCreateSQLWithoutName()
```
  - getCreateSQL
```
public java.lang.String getCreateSQL()
```
  - isNullable
```
public boolean isNullable()
```
  - setOriginalSQL
```
public void setOriginalSQL(java.lang.String original)
```
  - getOriginalSQL
```
public java.lang.String getOriginalSQL()
```
  - getDefaultExpression
```
public Expression getDefaultExpression()
```
  - getOnUpdateExpression
```
public Expression getOnUpdateExpression()
```
  - isAutoIncrement
```
public boolean isAutoIncrement()
```
  - setAutoIncrement
```
public void setAutoIncrement(boolean autoInc,
                             long start,
                             long increment)
```
    Set the autoincrement flag and related properties of this column.
    
    Parameters:
    
    autoInc - the new autoincrement flag
    
    start - the sequence start value
    
    increment - the sequence increment
  - setConvertNullToDefault
```
public void setConvertNullToDefault(boolean convert)
```
  - rename
```
public void rename(java.lang.String newName)
```
    Rename the column. This method will only set the column name to the new value.
    
    Parameters:
    
    newName - the new column name
  - setSequence
```
public void setSequence(Sequence sequence)
```
  - getSequence
```
public Sequence getSequence()
```
  - getSelectivity
```
public int getSelectivity()
```
    Get the selectivity of the column. Selectivity 100 means values are unique, 10 means every distinct value appears 10 times on average.
    
    Returns:
    
    the selectivity
  - setSelectivity
```
public void setSelectivity(int selectivity)
```
    Set the new selectivity of a column.
    
    Parameters:
    
    selectivity - the new value
  - addCheckConstraint
```
public void addCheckConstraint(Session session,
                               Expression expr)
```
    Add a check constraint expression to this column. An existing check constraint constraint is added using AND.
    
    Parameters:
    
    session - the session
    
    expr - the (additional) constraint
  - removeCheckConstraint
```
public void removeCheckConstraint()
```
    Remove the check constraint if there is one.
  - getCheckConstraint
```
public Expression getCheckConstraint(Session session,
                                     java.lang.String asColumnName)
```
    Get the check constraint expression for this column if set.
    
    Parameters:
    
    session - the session
    
    asColumnName - the column name to use
    
    Returns:
    
    the constraint expression
  - setComment
```
public void setComment(java.lang.String comment)
```
  - getComment
```
public java.lang.String getComment()
```
  - setPrimaryKey
```
public void setPrimaryKey(boolean primaryKey)
```
  - isPrimaryKey
```
public boolean isPrimaryKey()
```
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - isWideningConversion
```
public boolean isWideningConversion(Column newColumn)
```
    Check whether the new column is of the same type and not more restricted than this column.
    
    Parameters:
    
    newColumn - the new (target) column
    
    Returns:
    
    true if the new column is compatible
  - copy
```
public void copy(Column source)
```
    Copy the data of the source column into the current column.
    
    Parameters:
    
    source - the source column

Class Column

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ROWID

NOT_NULLABLE

NULLABLE

NULLABLE_UNKNOWN

Constructor Detail

Column

Column

Column

Method Detail

equals

hashCode

isEnumerated

getClone

convert

convert

setComputedExpression

setTable

getTable

setDefaultExpression

setOnUpdateExpression

getColumnId

getSQL

getName

getType

getPrecision

setPrecision

getDisplaySize

getScale

setNullable

getEnumerators

setEnumerators

getVisible

setVisible

validateConvertUpdateSequence

convertAutoIncrementToSequence

prepareExpression

getCreateSQLWithoutName

getCreateSQL

isNullable

setOriginalSQL

getOriginalSQL

getDefaultExpression

getOnUpdateExpression

isAutoIncrement

setAutoIncrement

setConvertNullToDefault

rename

setSequence

getSequence

getSelectivity

setSelectivity

addCheckConstraint

removeCheckConstraint

getCheckConstraint

setComment

getComment

setPrimaryKey

isPrimaryKey

toString

isWideningConversion

copy