Constraint (H2 Database Engine wt-1.0.1 API)

java.lang.Object
- org.h2.engine.DbObjectBase
- - org.h2.schema.SchemaObjectBase
  - - org.h2.constraint.Constraint

所有已实现的接口:

Comparable<Constraint>, DbObject, SchemaObject

直接已知子类:

ConstraintCheck, ConstraintReferential, ConstraintUnique
```
public abstract class Constraint
extends SchemaObjectBase
implements Comparable<Constraint>
```
The base class for constraint checking.

字段概要

字段
限定符和类型	字段和说明
`static String`	`CHECK` The constraint type name for check constraints.
`static String`	`PRIMARY_KEY` The constraint type name for primary key constraints.
`static String`	`REFERENTIAL` The constraint type name for referential constraints.
`protected Table`	`table` The table for which this constraint is defined.
`static String`	`UNIQUE` The constraint type name for unique constraints.

从类继承的字段 org.h2.engine.DbObjectBase
comment, database, trace

从接口继承的字段 org.h2.engine.DbObject
AGGREGATE, COMMENT, CONSTANT, CONSTRAINT, FUNCTION_ALIAS, INDEX, RIGHT, ROLE, SCHEMA, SEQUENCE, SETTING, TABLE_OR_VIEW, TRIGGER, USER, USER_DATATYPE

方法概要

所有方法实例方法抽象方法具体方法
限定符和类型	方法和说明
`abstract void`	`checkExistingData(Session session)` Check the existing data.
`void`	`checkRename()` Check if this object can be renamed.
`abstract void`	`checkRow(Session session, Table t, Row oldRow, Row newRow)` Check if this row fulfils the constraint.
`int`	`compareTo(Constraint other)`
`abstract String`	`getConstraintType()` The constraint type name
`abstract String`	`getCreateSQLWithoutIndexes()` Get the SQL statement to create this constraint.
`String`	`getDropSQL()` Build a SQL statement to drop this object.
`abstract HashSet<Column>`	`getReferencedColumns(Table table)` Get all referenced columns.
`Table`	`getRefTable()`
`Table`	`getTable()`
`int`	`getType()` Get the object type.
`abstract Index`	`getUniqueIndex()` Get the unique index used to enforce this constraint, or null if no index is used.
`abstract boolean`	`isBefore()` Check if this constraint needs to be checked before updating the data.
`boolean`	`isEverything(ExpressionVisitor visitor)` Visit all elements in the constraint.
`boolean`	`isHidden()` Check whether this is a hidden object that doesn't appear in the meta data and in the script, and is not dropped on DROP ALL OBJECTS.
`abstract void`	`rebuild()` This method is called after a related table has changed (the table was renamed, or columns have been renamed).
`abstract void`	`setIndexOwner(Index index)` This index is now the owner of the specified index.
`abstract boolean`	`usesIndex(Index index)` Check if this constraint needs the specified index.

从类继承的方法 org.h2.schema.SchemaObjectBase
getSchema, getSQL, initSchemaObjectBase

从类继承的方法 org.h2.engine.DbObjectBase
getChildren, getComment, getCreateSQL, getDatabase, getId, getModificationId, getName, initDbObjectBase, invalidate, isTemporary, isValid, removeChildrenAndResources, rename, setComment, setModified, setObjectName, setTemporary, toString

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

从接口继承的方法 org.h2.engine.DbObject
getChildren, getComment, getCreateSQL, getCreateSQLForCopy, getDatabase, getId, getName, isTemporary, removeChildrenAndResources, rename, setComment, setTemporary

- 字段详细资料
  - CHECK
```
public static final String CHECK
```
    The constraint type name for check constraints.
    
    另请参阅:
    
    常量字段值
  - REFERENTIAL
```
public static final String REFERENTIAL
```
    The constraint type name for referential constraints.
    
    另请参阅:
    
    常量字段值
  - UNIQUE
```
public static final String UNIQUE
```
    The constraint type name for unique constraints.
    
    另请参阅:
    
    常量字段值
  - PRIMARY_KEY
```
public static final String PRIMARY_KEY
```
    The constraint type name for primary key constraints.
    
    另请参阅:
    
    常量字段值
  - table
```
protected Table table
```
    The table for which this constraint is defined.
- 方法详细资料
  - getConstraintType
```
public abstract String getConstraintType()
```
    The constraint type name
    
    返回:
    
    the name
  - checkRow
```
public abstract void checkRow(Session session,
                              Table t,
                              Row oldRow,
                              Row newRow)
```
    Check if this row fulfils the constraint. This method throws an exception if not.
    
    参数:
    
    session - the session
    
    t - the table
    
    oldRow - the old row
    
    newRow - the new row
  - usesIndex
```
public abstract boolean usesIndex(Index index)
```
    Check if this constraint needs the specified index.
    
    参数:
    
    index - the index
    
    返回:
    
    true if the index is used
  - setIndexOwner
```
public abstract void setIndexOwner(Index index)
```
    This index is now the owner of the specified index.
    
    参数:
    
    index - the index
  - getReferencedColumns
```
public abstract HashSet<Column> getReferencedColumns(Table table)
```
    Get all referenced columns.
    
    参数:
    
    table - the table
    
    返回:
    
    the set of referenced columns
  - getCreateSQLWithoutIndexes
```
public abstract String getCreateSQLWithoutIndexes()
```
    Get the SQL statement to create this constraint.
    
    返回:
    
    the SQL statement
  - isBefore
```
public abstract boolean isBefore()
```
    Check if this constraint needs to be checked before updating the data.
    
    返回:
    
    true if it must be checked before updating
  - checkExistingData
```
public abstract void checkExistingData(Session session)
```
    Check the existing data. This method is called if the constraint is added after data has been inserted into the table.
    
    参数:
    
    session - the session
  - rebuild
```
public abstract void rebuild()
```
    This method is called after a related table has changed (the table was renamed, or columns have been renamed).
  - getUniqueIndex
```
public abstract Index getUniqueIndex()
```
    Get the unique index used to enforce this constraint, or null if no index is used.
    
    返回:
    
    the index
  - checkRename
```
public void checkRename()
```
    从类复制的说明: DbObjectBase
    
    Check if this object can be renamed. System objects may not be renamed.
    
    指定者:
    
    checkRename 在接口中 DbObject
    
    指定者:
    
    checkRename 在类中 DbObjectBase
  - getType
```
public int getType()
```
    从接口复制的说明: DbObject
    
    Get the object type.
    
    指定者:
    
    getType 在接口中 DbObject
    
    返回:
    
    the object type
  - getTable
```
public Table getTable()
```
  - getRefTable
```
public Table getRefTable()
```
  - getDropSQL
```
public String getDropSQL()
```
    从类复制的说明: DbObjectBase
    
    Build a SQL statement to drop this object.
    
    指定者:
    
    getDropSQL 在接口中 DbObject
    
    指定者:
    
    getDropSQL 在类中 DbObjectBase
    
    返回:
    
    the SQL statement
  - compareTo
```
public int compareTo(Constraint other)
```
    指定者:
    
    compareTo 在接口中 Comparable<Constraint>
  - isHidden
```
public boolean isHidden()
```
    从接口复制的说明: SchemaObject
    
    Check whether this is a hidden object that doesn't appear in the meta data and in the script, and is not dropped on DROP ALL OBJECTS.
    
    指定者:
    
    isHidden 在接口中 SchemaObject
    
    覆盖:
    
    isHidden 在类中 SchemaObjectBase
    
    返回:
    
    true if it is hidden
  - isEverything
```
public boolean isEverything(ExpressionVisitor visitor)
```
    Visit all elements in the constraint.
    
    参数:
    
    visitor - the visitor
    
    返回:
    
    true if every visited expression returned true, or if there are no expressions

类 Constraint

字段概要

从类继承的字段 org.h2.engine.DbObjectBase

从接口继承的字段 org.h2.engine.DbObject

方法概要

从类继承的方法 org.h2.schema.SchemaObjectBase

从类继承的方法 org.h2.engine.DbObjectBase

从类继承的方法 java.lang.Object

从接口继承的方法 org.h2.engine.DbObject

字段详细资料

CHECK

REFERENTIAL

UNIQUE

PRIMARY_KEY

table

方法详细资料

getConstraintType

checkRow

usesIndex

setIndexOwner

getReferencedColumns

getCreateSQLWithoutIndexes

isBefore

checkExistingData

rebuild

getUniqueIndex

checkRename

getType

getTable

getRefTable

getDropSQL

compareTo

isHidden

isEverything