Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.iapi.sql.conn.SQLSessionContext

An implementation of this interface encapsulates some of the SQL session context's state variables, cf. SQL 2003, section 4.37.3, notably those which we need to save and restore when entering a stored procedure or function (which can contain SQL and thus a nested connection), cf. 4.37.3, 4.27.3 and 4.34.1.1.

Presently this set contains the following properties:

current role
current schema

The standard specifies that the authorization stack be copied onto the new SQL session context before it is pushed (and possibly modifed) with a new cell for the authorization ids (user, role). In our implementation we merge these two stacks for now. Also, the authorization id of current user is not represented yet, since it can not be modified in a session; Derby can not run routines with definer's rights yet.

SQL session context is implemented as follows: Statements at root connection level use the instance held by the the lcc, nested connections maintain instances of SQLSessionContext, held by the activation of the calling statement. This forms a logical stack as required by the standard. The statement context also holds a reference to the current SQLSessionContext.

When a dynamic result set references e.g. current role, the value retrieved will always be that of the current role when the statement is logically executed (inside procedure/function), not the current value when the result set is accessed outside the stored procedure/function. This works since the nested SQL session context is kept by the caller activation, so even though the statement context of the call has been popped, we can get at the final state of the nested SQL session context since the caller's activation is alive as long as dynamic result sets need it).

If more than one nested connection is used inside a shared procedure, they will share the same nested SQL session context. Since the same dynamic call context is involved, this seems correct.

Method Summary

Modifier and Type	Method and Description
public HashMap<UUID, Boolean>	Returns: constraint modes map getConstraintModes() Get a handle to the session's constraint modes.
public String	getCurrentUser() Get the SQL current user of this SQL connection context
public SchemaDescriptor	getDefaultSchema() Get the schema of this SQL connection context
public Boolean	Returns: `True` is deferred all constraint mode has been set for this session context. `False` is deferred immediate has been set for this session context. `null` means no ALL setting has been made for this context getDeferredAll() Get state of DEFERRED ALL setting.
public String	getRole() Get the SQL role of this SQL connection context
public Boolean	Returns: `Boolean.TRUE` if the constraint mode for this constraint/index has been set to deferred, `Boolean.FALSE` if it has been set to immediate. isDeferred(UUID the constraint id constraintId) Return `Boolean.TRUE` if the constraint mode for this constraint/index has been set to deferred, `Boolean.FALSE` if it has been set to immediate.
public void	resetConstraintModes() Clear deferred information for this transaction.
public void	setConstraintModes(HashMap<UUID, Boolean> constraint mode map hm) Initialize a inferior session context with the constraint mode map of the parent session context.
public void	setDefaultSchema(SchemaDescriptor sd) Set the schema of this SQL connection context
public void	setDeferred(UUID The constraint id constraintId, boolean The new constraint mode deferred) Set the constraint mode for this constraint to `deferred`.
public void	setDeferredAll(Boolean the mode to set deferred) Set the constraint mode for all deferrable constraints to `deferred`.
public void	setRole(String role) Set the SQL role of this SQL connection context
public void	setUser(String user) Set the SQL current user of this SQL connection context

Method Detail

getConstraintModes	back to summary
public HashMap<UUID, Boolean> getConstraintModes() Get a handle to the session's constraint modes. The caller is responsible for any cloning needed. Returns:HashMap<UUID, Boolean> constraint modes map

getConstraintModes

back to summary

public HashMap<UUID, Boolean> getConstraintModes()

Get a handle to the session's constraint modes. The caller is responsible for any cloning needed.

Returns:HashMap<UUID, Boolean>: constraint modes map

getCurrentUser	back to summary
public String getCurrentUser() Get the SQL current user of this SQL connection context

getDefaultSchema	back to summary
public SchemaDescriptor getDefaultSchema() Get the schema of this SQL connection context

getDeferredAll back to summary

getDeferredAll	back to summary
public Boolean getDeferredAll() Get state of DEFERRED ALL setting. Returns:Boolean `True` is deferred all constraint mode has been set for this session context. `False` is deferred immediate has been set for this session context. `null` means no ALL setting has been made for this context

public Boolean getDeferredAll()

Get state of DEFERRED ALL setting.

Returns:Boolean: True is deferred all constraint mode has been set for this session context. False is deferred immediate has been set for this session context. null means no ALL setting has been made for this context

getRole	back to summary
public String getRole() Get the SQL role of this SQL connection context

isDeferred back to summary

isDeferred	back to summary
public Boolean isDeferred(UUID constraintId) Return `Boolean.TRUE` if the constraint mode for this constraint/index has been set to deferred, `Boolean.FALSE` if it has been set to immediate. Any ALL setting is considered also. If the constraint mode hasn't been set for this constraint, return `null`. The constraint mode is the effectively the initial constraint mode in this case. Parameters constraintId:UUID the constraint id Returns:Boolean `Boolean.TRUE` if the constraint mode for this constraint/index has been set to deferred, `Boolean.FALSE` if it has been set to immediate.

public Boolean isDeferred(UUID constraintId)

Return Boolean.TRUE if the constraint mode for this constraint/index has been set to deferred, Boolean.FALSE if it has been set to immediate. Any ALL setting is considered also. If the constraint mode hasn't been set for this constraint, return null. The constraint mode is the effectively the initial constraint mode in this case.

Parameters

constraintId:UUID: the constraint id

Returns:Boolean

Boolean.TRUE if the constraint mode for this constraint/index has been set to deferred, Boolean.FALSE if it has been set to immediate.

resetConstraintModes	back to summary
public void resetConstraintModes() Clear deferred information for this transaction.

setConstraintModes	back to summary
public void setConstraintModes(HashMap<UUID, Boolean> hm) Initialize a inferior session context with the constraint mode map of the parent session context. Parameters hm:HashMap<UUID, Boolean> constraint mode map

setConstraintModes

back to summary

public void setConstraintModes(HashMap<UUID, Boolean> hm)

Initialize a inferior session context with the constraint mode map of the parent session context.

Parameters

hm:HashMap<UUID, Boolean>: constraint mode map

setDefaultSchema	back to summary
public void setDefaultSchema(SchemaDescriptor sd) Set the schema of this SQL connection context

setDeferred back to summary

setDeferred	back to summary
public void setDeferred(UUID constraintId, boolean deferred) Set the constraint mode for this constraint to `deferred`. If `deferred` is `false`, to immediate checking, if `true` to deferred checking. Parameters constraintId:UUID The constraint id deferred:boolean The new constraint mode

public void setDeferred(UUID constraintId, boolean deferred)

Set the constraint mode for this constraint to deferred. If deferred is false, to immediate checking, if true to deferred checking.

Parameters

constraintId:UUID: The constraint id
deferred:boolean: The new constraint mode

setDeferredAll back to summary

setDeferredAll	back to summary
public void setDeferredAll(Boolean deferred) Set the constraint mode for all deferrable constraints to `deferred`. If `deferred` is `false`, set to immediate checking, if `true` to deferred checking. `null` is allowed: it means no ALL setting exists. Parameters deferred:Boolean the mode to set

public void setDeferredAll(Boolean deferred)

Set the constraint mode for all deferrable constraints to deferred. If deferred is false, set to immediate checking, if true to deferred checking. null is allowed: it means no ALL setting exists.

Parameters

deferred:Boolean: the mode to set

setRole	back to summary
public void setRole(String role) Set the SQL role of this SQL connection context

setUser	back to summary
public void setUser(String user) Set the SQL current user of this SQL connection context

public Interface SQLSessionContext

Method Summary

Method Detail