31. TDataSource, TDBEdit, TDBGrid, TDBNavigator.
, .
TDataSource
DataSource TDataSet (TTable, TQuery, TStoredProc) Data Controls - , . TDataSet Borland Database Engine (BDE), DataSource Data Controls.
DataSource, , TDataSet (TTable TQuery) Data Controls (, DBGrid, DBEdit .). TDataSet DataControls :
C DataSet DataSource TDataSet. DataSet .
C Enabled DataSource TDataSource Data Controls. Enabled true, Data Controls, TDataSource, . Enabled Data Controls TDataSource, , , .
AutoEdit DataSource , Data Controls. AutoEdit true, Data Controls, TDataSet. , Edit TDataSet, , Edit DBNavigator. OnDataChange DataSource , , , , .
C OnUpdateData DataSource , TDataSet. , , .
TDBEdit
, .
TCustomMaskEdit, TEdit.
. , . . EditMask TCustomMaskEdit , TDBEdit . . . TField EditMask, (. . 13).
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validateEdit . validateError .
. CopyToClipboard, CutToClipboard, PasteFromCiipboard.
TDBGrid
TDBGrid TTable TQuery. TDBGrid , , , . DBGrid DBNavigator, , First, Last, Next, Ptior, Insert, Delete, Edit, Append, Post, Cancel TTable.
(, ) Columns Editor. Columns Editor DBGrid Columns .
DBGrid TField. TField, , , , , , DBGrid .
Float, Integer Date DisplayMask. , DBGrid Data Controls. , mm-dd-yy .
TField (, TStringField) EditMask, , DBGrid Data Controls. EditMask Field Object Inspector EditMask, Input Mask Editor, . 5. , Test Input.
TDBNavigator
. , TDBGrid TDBCtrlGrid, , .
, , (TDBEdit, TDBComb . .)? , , .
, .
TDBNavigator, , .
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TDBNavigator DataSource TDataSource . TDataSource . , TDBNavigator , TDataSource. .
. 15.4. TDBNavigator
TDBNavigator , . 10 , . visibleButtons:
type
TNavigateBtn = (nbFirst, nbPrior, nbNext, nbLast, nblnsert, nbDelete,
nbEdit, nbPost, nbCancel, nbRefresh);
TButtonSet = set of TNavigateBtn;
property VisibieButtons: TButtonSet;
TNavigateBtn , :
nbFirst ;
nbPrior ;
nbNext ;
nbLast ;
nblnsert ;
nbDelete , ;
nbEdit ;
nbPost ;
nbcancel ;
nbRefresh , .
, confirmDelete . .
BtnClick.
BeforeAction Onciick, Button .
TDatabase
, , BDE (), . TTable, TQuery, TStoredProc DatabaseName, , . , - (, , , ) BDE. TDatabase, . DatabaseName , DatabaseName TTable, TQuery, TS toredProc.
, , TDatabase ( ), . , Borland Database Engine, TTable, TQuery, TStoredProc, .
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TDatabase Database Editor .
Database Editor (.. BDE , , TDatabase) , . Defaults , ( , ), Parameter Overrides, . Login prompt, ( , , ). Keep inactive connection , , . , .
, - TDatabase.
TDatabase . , TTable, TQuery TStoredProc TDatabase, . , , , , , , , BDE, , , . , , , TDatabase ( TDatabase, ), DatabaseName TTable, TQuer y, TStoredProc , TDatabase.
, TDatabase, SQLPassThruMode, , (.. ), TTable TQuery, . - NOT SHARED, SHARED AUTOCOMMIT SHARED NOAUTOCOMMIT.
NOT SHARED TQuery TTable , (, TTable SQL- , TQuery).
SHARED AUTOCOMMIT. , (TTable TQuery) , , .
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- SHARED NOAUTOCOMMIT. TTable TQuery , , .
Transisolation TDatabase . , , - , , . , , - , , , .
Transisolation, tiDirtyRead, , , , . , , . , .
tiReadCommitted , , , , . .
tiRepeatableRead . , , , . . , , , , , . tiRepeatableRead.
, true Cached Updates TTable TQuery. ApplyUpdates() TTable TQuery.
. -, , , , . -, , , - , false, , . CancelUpdates().
, ApplyUpdates , , . ApplyUpdates , , , , .
Database . ORACLE 7 CLIENTS.DBF C++Builder DBDEMOS (, Data Migration Wizard) .
1. , CachedUpdates Table1 true.
TTable
TTable, . :
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Active - , (true) (false) .
DatabaseName - , , (alias) ( BDE, , Borland, SQL Explorer, Database/Explore). , ( Active false).
TableName - .
Exclusive - true, , . false ( ), .
IndexName - . , .
MasterFields - .
MasterSource - TDataSource, TTable .
ReadOnly - true, " ". ReadOnly, .
Eof, Bof - true, .
Fields - TField. , , , :
Edit1->Text=Table1->Fields[2]->AsString;TTable :
Open Close Active True False .
Refresh .
First, Last, Next, Prior , , .
MoveBy ( )
Insert, Edit, Delete, Append - , , , .
Post - .
Cancel - , .
FieldByName - :
SetKey .
GotoKey , Fields[n] , n - , 0:
SetRangeStart, SetRangeEnd, ApplyRange - .
FreeBookmark, GetBookmark, GotoBookmark- . Bookmark TBookmark. GetBookmark c . GotoBookmark , . FreeBookmark TBookmark:
C TTable . , BeforePost , AfterPost - , AfterDelete - ..
TTable , :
1. Data Access , TTable .
2. DatabaseName , , .
3. TableName .
4. DataSource DataSet TTable.
5. Data Controls DataSource , .
TQuery
TTable, . TTable, TQuery ( SQL) . , TQuery TTable, .
SQL TQuery :
1. (Alias) DatabaseName.
2. SQL SQL "Select * from Country".
3. Active True
, , .
, , :
SQL, , , TQuery , . SQL, , , , SQL. , , , .
Delphi pass through SQL, SQL . SQL (Local SQL) , . , , LOCALSQL.HLP.
, TQuery , Delphi. , SQL , InrterBase, Oracle Sybase.
SQL - , TQuery. (design time), (run time).
, , SQL , . , SQL , TQuery . SQL . , - , . , SQL, , .
SQL TStrings, , . , , , , . .
TQuery, SQL:
Query1.Close;Query1.SQL.Clear;, "" Close. , , .
- :
Query1.SQL.Add('Select * from Country');Query1.SQL.Add('where Name = ''Argentina''');Add SQL. .
Delphi , , :
Query1.Open;TStoredProc
TStoredProc ), ( ) , - . , .
TStoredProc: DatabaseName - (alias) , , StoredProcName - , Params ( TParams) - , , TDataS e t: Active, Fields, Eof, Bof, State . : ExecProc - , ParamByName - , . TStoredProc , TDataSet: Append, AppendRecord, Close, Ope n, Delete, Edit, Post ..
32. TField, ,
.
TField TDataSet (, , TField - ).
Fields TDataSet . Fields TField, . .
TField , . , , , AsString, AsBoolean, AsFloat, AsInteger. Text (c , ) FieldName ( ).
Fields Editor , . TDataSet, TTable TQuery, SQL-. Fields Editor Field . Fields Editor , TDataSet, TField, , .
Fields Editor :
1. TTable TQuery .
2. DatabaseName TTable TQuery.
3. TableName TTable SQL TQuery.
4. TDataSet , .
5. Fields ditor. , TTable.
6. Add Fields.
7. , , OK.
8. , New Field ( OnCalcFields TTable, ).
9. , Delete.
, Fields Editor , , - h- .
drag-and-drop Fields Editor , , ( - DBEdit, , , , , DBImage, Clipboard ). TDBNavigator ( TTable TQuery, ) TDataSource, , .