А.С.Грошев.Базы данных.Уч.пособие

select count( * ) into numrows from "Spect"

where :new_ins."n_spect" = "Spect"."n_spect";

IF ( numrows = 0 ) then begin

RAISE_APPLICATION_ERROR(-20004,'Parent does not exist. Cannot insert child.'); end;

end if; end; end if;

-- restrict child Spisok when parent Fclt insert if (:new_ins."n_fclt" is not null) then

begin select count( * ) into numrows from "Fclt"

where :new_ins."n_fclt" = "Fclt"."n_fclt";

IF ( numrows = 0 ) then begin

RAISE_APPLICATION_ERROR(-20004,'Parent does not exist. Cannot insert child.'); end;

end if; end; end if; end;

/

-- Insert trigger for Ocenki

Create Trigger "ti_Ocenki" after insert on "Ocenki"

referencing new as new_ins for each row declare numrows integer;

begin

-- restrict child Ocenki when parent Predmets insert if (:new_ins."n_predm" is not null) then

begin select count( * ) into numrows from "Predmets"

where :new_ins."n_predm" = "Predmets"."n_predm";

IF ( numrows = 0 ) then begin

RAISE_APPLICATION_ERROR(-20004,'Parent does not exist. Cannot insert child.'); end;

end if; end; end if;

-- restrict child Ocenki when parent Spisok insert if (:new_ins."NZ" is not null) then

begin select count( * ) into numrows from "Spisok"

where :new_ins."NZ" = "Spisok"."NZ";

IF ( numrows = 0 ) then begin

RAISE_APPLICATION_ERROR(-20004,'Parent does not exist. Cannot insert child.'); end;

end if; end; end if; end;

/

Create role "Programmer"

/

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Create role "operator"

/

Create role "Dekan"

/

/* Roles permissions */

Grant select on "Spisok" to "Programmer"

/

Grant update on "Spisok" to "Programmer"

/

Grant delete on "Spisok" to "Programmer"

/

Grant insert on "Spisok" to "Programmer"

/

Grant references on "Spisok" to "Programmer"

/

Grant select on "Spisok" to "Dekan"

/

Grant update on "Spisok" to "Dekan"

/

Grant delete on "Spisok" to "Dekan"

/

Grant insert on "Spisok" to "Dekan"

/

Grant references on "Spisok" to "Dekan"

/

Grant select on "Ocenki" to "Programmer"

/

Grant update on "Ocenki" to "Programmer"

/

Grant delete on "Ocenki" to "Programmer"

/

Grant insert on "Ocenki" to "Programmer"

/

Grant references on "Ocenki" to "Programmer"

/

Grant select on "Ocenki" to "operator"

/

Grant update on "Ocenki" to "operator"

/

Grant delete on "Ocenki" to "operator"

/

Grant insert on "Ocenki" to "operator"

/

Grant references on "Ocenki" to "operator"

/

Grant select on "Fclt" to "Programmer"

/

Grant update on "Fclt" to "Programmer"

/

Grant delete on "Fclt" to "Programmer"

/

Grant insert on "Fclt" to "Programmer"

/

Grant references on "Fclt" to "Programmer"

/

Grant select on "Spect" to "Programmer"

/

Grant update on "Spect" to "Programmer"

/

Grant delete on "Spect" to "Programmer"

/

Grant insert on "Spect" to "Programmer"

/

Grant references on "Spect" to "Programmer"

/

Grant select on "Spect" to "Dekan"

/

Grant update on "Spect" to "Dekan"

/

32

Grant delete on "Spect" to "Dekan"

/

Grant insert on "Spect" to "Dekan"

/

Grant references on "Spect" to "Dekan"

/

Grant select on "Predmets" to "Programmer"

/

Grant update on "Predmets" to "Programmer"

/

Grant delete on "Predmets" to "Programmer"

/

Grant insert on "Predmets" to "Programmer"

/

Grant references on "Predmets" to "Programmer"

/

Grant select on "Predmets" to "Dekan"

/

Grant update on "Predmets" to "Dekan"

/

Grant delete on "Predmets" to "Dekan"

/

Grant insert on "Predmets" to "Dekan"

/

Grant references on "Predmets" to "Dekan"

/

/* Users permissions */

Grant select on "Fclt" to "Pavlov"

/

Grant update on "Fclt" to "Pavlov"

/

Grant delete on "Fclt" to "Pavlov"

/

Grant insert on "Fclt" to "Pavlov"

/

Grant references on "Fclt" to "Pavlov"

/

Grant select on "Spect" to "Pavlov"

/

Grant update on "Spect" to "Pavlov"

/

Grant delete on "Spect" to "Pavlov"

/

Grant insert on "Spect" to "Pavlov"

/

Grant references on "Spect" to "Pavlov"

/

Grant select on "Predmets" to "Pavlov"

/

Grant update on "Predmets" to "Pavlov"

/

Grant delete on "Predmets" to "Pavlov"

/

Grant insert on "Predmets" to "Pavlov"

/

Grant references on "Predmets" to "Pavlov"

/

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Приложение 1.2 Сгенерированная Case Studio программа создания таблиц базы данных для СУБД Access

'======================================================= '=== MS Access 2000 database creation method

'===

'=== 1. Create a new database in the MS Access 2000 '=== 2. Create a new module

'=== 3. Copy the CASE Studio 2 output SQL script into the new MS Access 2000 module

'=== 4. Select from main menu "Tools" item "References..." and check the "Microsoft DAO 3.6 Object

Library."

'=== 5. Place your mouse cursor somewhere in the main procedure Main()

'=== 6. Run the module code (Click the "Run Sub/UserForm" button or press F5) '=======================================================

Public dbs As DAO.Database

Public tdf As DAO.TableDef

Public idx As DAO.Index

Public rel As DAO.Relation

Sub Main()

Set dbs = CurrentDb()

On Error GoTo ErrorHandler Call CreateTables

Call CreatePrimaryKeys Call CreateIndexes Call CreateAlterKeys Call CreateRelations Call CreateQueries

MsgBox "Script successfully processed.", vbInformation Exit Sub

ErrorHandler:

Select Case Err.Number Case 3010

MsgBox "Table " & tdf.Name & " allready exist!", vbInformation Err.Clear

Case 3284

MsgBox "Index " & idx.Name & " for table " & tdf.Name & " allready exist!", vbInformation Err.Clear

Case Else

MsgBox Err.Description, vbCritical

End Select

End Sub

' Create tables '=============== Sub CreateTables()

Call CreateTable1 'Spisok Call CreateTable2 'Ocenki Call CreateTable3 'Fclt Call CreateTable4 'Spect

34

Call CreateTable5 'Predmets

End Sub

'=== Create table Spisok ======

Sub CreateTable1()

Set tdf = dbs.CreateTableDef( "Spisok" )

Call AddFieldToTable("NZ", dbText, 7, 0, "", "", "", TRUE ) Call AddFieldToTable("FIO", dbText, 45, 0, "", "", "", TRUE )

Call AddFieldToTable("data_p", dbDate, 0, 0, "", "", "", FALSE ) Call AddFieldToTable("n_fclt", dbLong, 0, 0, "", "", "", TRUE ) Call AddFieldToTable("n_spect", dbLong, 0, 0, "", "", "", TRUE ) Call AddFieldToTable("kurs", dbLong, 0, 0, "", "", "", TRUE ) Call AddFieldToTable("n_grup", dbText, 3, 0, "", "", "", TRUE ) Call AddFieldToTable("n_pasp", dbText, 10, 0, "", "", "", FALSE ) dbs.TableDefs.Append tdf

End Sub

'=== Create table Ocenki ======

Sub CreateTable2()

Set tdf = dbs.CreateTableDef( "Ocenki" )

Call AddFieldToTable("NZ", dbText, 7, 0, "", "", "", TRUE )

Call AddFieldToTable("semestr", dbLong, 0, 0, "", "", "", FALSE ) Call AddFieldToTable("n_predm", dbLong, 0, 0, "", "", "", TRUE ) Call AddFieldToTable("ball", dbText, 1, 0, "", "", "", FALSE )

Call AddFieldToTable("data_b", dbDate, 0, 0, "", "", "", FALSE ) Call AddFieldToTable("prepod", dbLong, 0, 0, "", "", "", FALSE ) dbs.TableDefs.Append tdf

End Sub

'=== Create table Fclt ======

Sub CreateTable3()

Set tdf = dbs.CreateTableDef( "Fclt" )

Call AddFieldToTable("n_fclt", dbLong, 0, 0, "", "", "", TRUE ) Call AddFieldToTable("name_f", dbText, 120, 0, "", "", "", FALSE ) dbs.TableDefs.Append tdf

End Sub

'=== Create table Spect ======

Sub CreateTable4()

Set tdf = dbs.CreateTableDef( "Spect" )

Call AddFieldToTable("n_spect", dbLong, 0, 0, "", "", "", TRUE ) Call AddFieldToTable("name_s", dbText, 120, 0, "", "", "", FALSE ) dbs.TableDefs.Append tdf

End Sub

'=== Create table Predmets ======

Sub CreateTable5()

Set tdf = dbs.CreateTableDef( "Predmets" )

Call AddFieldToTable("n_predm", dbLong, 0, 0, "", "", "", TRUE ) Call AddFieldToTable("name_p", dbText, 120, 0, "", "", "", FALSE ) dbs.TableDefs.Append tdf

End Sub

' Create primary keys '===================== Sub CreatePrimaryKeys()

'=== Create primary key for table Spisok ======

Set tdf = dbs.TableDefs( "Spisok" )

Set idx = tdf.CreateIndex( "pk_Spisok" ) idx.Primary = True

idx.Unique = True

35

idx.IgnoreNulls = False

Call AddFieldToIndex( "NZ", False ) tdf.Indexes.Append idx

'=== Create primary key for table Fclt ======

Set tdf = dbs.TableDefs( "Fclt" )

Set idx = tdf.CreateIndex( "pk_Fclt" ) idx.Primary = True

idx.Unique = True idx.IgnoreNulls = False

Call AddFieldToIndex( "n_fclt", False ) tdf.Indexes.Append idx

'=== Create primary key for table Spect ======

Set tdf = dbs.TableDefs( "Spect" )

Set idx = tdf.CreateIndex( "pk_Spect" ) idx.Primary = True

idx.Unique = True idx.IgnoreNulls = False

Call AddFieldToIndex( "n_spect", False ) tdf.Indexes.Append idx

'=== Create primary key for table Predmets ======

Set tdf = dbs.TableDefs( "Predmets" )

Set idx = tdf.CreateIndex( "pk_Predmets" ) idx.Primary = True

idx.Unique = True idx.IgnoreNulls = False

Call AddFieldToIndex( "n_predm", False ) tdf.Indexes.Append idx

End Sub

'Create indexes '================ Sub CreateIndexes() End Sub

'Create alter keys (unique indexes in MS ACCESS) '================================================ Sub CreateAlterKeys()

End Sub

'Create relations

'================== Sub CreateRelations()

'=== Create relations between parent table Spisok and child table Ocenki ======

Set rel = dbs.CreateRelation("Spisok_Ocenki")

Call AddFieldToRelation("NZ", "NZ") dbs.Relations.Append rel

'=== Create relations between parent table Fclt and child table Spisok ======

Set rel = dbs.CreateRelation("Fclt_Spisok")

Call AddFieldToRelation("n_fclt", "n_fclt") dbs.Relations.Append rel

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'=== Create relations between parent table Spect and child table Spisok ======

Set rel = dbs.CreateRelation("Spect_Spisok")

Call AddFieldToRelation("n_spect", "n_spect") dbs.Relations.Append rel

'=== Create relations between parent table Predmets and child table Ocenki ======

Set rel = dbs.CreateRelation("Predmets_Ocenki")

Call AddFieldToRelation("n_predm", "n_predm") dbs.Relations.Append rel

End Sub

'Create queries '================ Sub CreateQueries() Dim qdf As QueryDef End Sub

'Add fields to table '=====================

Sub AddFieldToTable(FieldName As String, DataType As String, SizeCol As Integer, Attributes As

Long, DefaultValue As Variant, ValText As String, ValRule As String, NotN As Boolean)

'Add properties to table '=========================

Sub AddPropertyToTable( PropertyName As String, Value As Variant, DataType As String) Dim prp As DAO.Property

Set prp = tdf.CreateProperty(PropertyName, DataType, Value) tdf.Properties.Append prp

End Sub

'Add properties to field

'=========================

Sub AddPropertyToField( FieldName As String, PropertyName As String, Value As Variant, DataType As String)

Dim prp As DAO.Property Dim fld As DAO.Field

Set fld = tdf.Fields( FieldName )

Set prp = fld.CreateProperty(PropertyName, DataType, Value) fld.Properties.Append prp

End Sub

' Add fields to index '=====================

Sub AddFieldToIndex( FieldName As String, Descending As Boolean ) Dim fld As DAO.Field

Set fld = idx.CreateField( FieldName )

37

If Descending = True Then fld.Attributes = dbDescending idx.Fields.Append fld

End Sub

' Add fields to relation '========================

Sub AddFieldToRelation( PKField As String, FKField As String ) Dim fld As DAO.Field

Set fld = rel.CreateField( PKField ) fld.ForeignName = FKField rel.Fields.Append fld

End

Sub

38

Глава 2. Основы работы с базами данных в системе

Visual FoxPro

2.1. Общая характеристика системы

Visual FoxPro (VFP) – современная СУБД для персональных компьютеров, использующая реляционные базы данных, имеющая объектноориентированный алгоритмический язык для работы с информацией, методы визуального программирования и достаточно большие возможности (табл. 2.1). Версия системы 7.0 может работать в операционных системах Windows 9x и ядра NT, версии 8.0 и 9.0 – только в Windows 2000, 2003 и XP.

Таблица 2.1. Основные максимальные возможности системы Visual FoxPro

Некоторые достоинства системы:

1.Наиболее известный формат таблиц баз данных, что позволяет легко организовать обмен информацией с другими приложениями Microsoft

Windows.

2.Современная организация реляционных баз данных, позволяющая хранить информацию о таблицах базы, их свойствах, индексах и связях, локальных и удаленных представлениях (Views), связях с серверами, о хранимых процедурах, исполняемых при наступлении более 50 различных видов со-

бытий (VFP 7.0 – 9.0).

3.Высокая скорость работы с большими базами данных.

4.Высокая наглядность работы с базами данных: многофункциональное окно Data session позволяет видеть список открытых таблиц баз данных, их связи, фильтры, порядок по индексам, режимы буферизации, переходить к режимам модификации структуры, к работе с информацией таблиц и пр..

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