Get all foreignkeys in use in a given table (MS SQL Server)
The system stored procedure “sp_fkeys ([tablename])” will only give a list of foreign key references to the given table.
The “GetForeignKeys” function above will give you the list of fields that are “foreign hold” from other tables.
Try out: You’ll need an AdoConnection to your DB …
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unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, Grids, DBGrids, DB, ADODB, StdCtrls, DBCtrls; type TForm1 = class(TForm) ADOConnection1: TADOConnection; Memo1: TMemo; BStart: TButton; procedure BStartClick(Sender: TObject); private procedure GetForeignKeys(sTableName: string; MyConnection: TADOConnection; var SlForeignKeyName, SlKeysActTable, SlKeysForeignTable, SlForeignKeyTable: TStringList); public { Public-Deklarationen } end; var Form1: TForm1; implementation {$R *.dfm} (* Get foreign keys *) procedure TForm1.GetForeignKeys(sTableName: string; MyConnection: TADOConnection; var SlForeignKeyName, SlKeysActTable, SlKeysForeignTable, SlForeignKeyTable: TStringList); var MySelectQuery, MyRecordQuery: TADOQuery; i: Integer; SlKeysAct, SlKeysFor: TStringList; sConstraintName, sForeignKeys, sForeignTable: string; (* Schlüssel ermitteln *) procedure GetKeys(sKeyList: string; fAct: Boolean); var i: Integer; sKey: string; begin i := 0; repeat Inc(i); if sKeyList[i] <> ',' then begin sKey := sKey + sKeyList[i]; end else begin if fAct then begin SlKeysAct.Add(sKey); end else begin SlKeysFor.Add(sKey); end; if (Length(sKey) + 1) < i then begin if sKey[(i + 1)] = ' ' then begin Inc(i); end; end; sKey := ''; end; until (i = Length(sKeyList)); if sKey <> '' then begin if fAct then begin SlKeysAct.Add(sKey); end else begin SlKeysFor.Add(sKey); end; end; end; procedure GetForeignKeyFieldsAndTable(sSQL: string); var i: Integer; sValue: string; iPos: Integer; fAddValue: Boolean; fInFields: Boolean; begin if Length(sSQL) >= 10 then begin (* REFERENCES entfernen *) sValue := Copy(sSQL, 1, 10); if AnsiUpperCase(sValue) = 'REFERENCES' then begin Delete(sSQL, 1, 11); end; i := 0; iPos := 0; sValue := ''; fInFields := False; repeat Inc(i); fAddValue := False; (* "normal" lesen *) if (sSQL[i] <> '.') and (sSQL[i] <> ' ') and (sSQL[i] <> '(') and (sSQL[i] <> ')') and (fInFields = False) then begin sValue := sValue + sSQL[i]; fAddValue := True; end; (* In Felder *) if sSQL[i] = '(' then begin fInFields := True; end; if (fInFields) and (sSQL[i] <> '(') and (sSQL[i] <> ')') then begin sValue := sValue + sSQL[i]; end; (* Felder verlassen *) if sSQL[i] = ')' then begin fInFields := False; end; if (fAddValue = False) and (fInFields = False) then begin case iPos of (* Datenbank *) 0: begin sValue := ''; Inc(iPos); end; (* Ower *) 1: begin sValue := ''; Inc(iPos); end; (* Tabelle *) 2: begin sForeignTable := sValue; sValue := ''; Inc(iPos); end; (* Felder *) 3: begin sForeignKeys := sValue; sValue := ''; Inc(iPos); end; else begin end; end; end; until (i = Length(sSQL)); end; end; begin try MySelectQuery := TADOQuery.Create(Application); with MySelectQuery do begin Name := 'MyHelpSelectQuery'; Connection := MyConnection; SQL.Add('sp_help ' + sTableName); Active := True; end; try MyRecordQuery := TADOQuery.Create(Application); with MySelectQuery do begin Name := 'MyHelpRecordQuery'; Connection := MyConnection; Recordset := MySelectQuery.NextRecordset(i); Recordset := MySelectQuery.NextRecordset(i); Recordset := MySelectQuery.NextRecordset(i); Recordset := MySelectQuery.NextRecordset(i); Recordset := MySelectQuery.NextRecordset(i); if MySelectQuery.State = dsBrowse then begin Recordset := MySelectQuery.NextRecordset(i); if FindField('Constraint_Type') <> nil then begin SlKeysAct := TStringList.Create; SlKeysFor := TStringList.Create; try while not EOF do begin if AnsiUpperCase(FieldByName('Constraint_Type').AsString) = AnsiUpperCase('FOREIGN KEY') then begin SlKeysAct.Clear; (* In einzelne Felder teilen *) GetKeys(FieldByName('Constraint_Keys').AsString, True); (* Constraint festhalten *) sConstraintName := FieldByName('Constraint_Name').AsString; (* Referenz steht im nächsten Datensatz *) Next; (* Tabelle und Felder auflösen *) GetForeignKeyFieldsAndTable(FieldByName('Constraint_Keys').AsString); (* In einzelne Felder teilen *) SlKeysFor.Clear; GetKeys(sForeignKeys, False); for i := 0 to (SlKeysAct.Count - 1) do begin SlForeignKeyName.Add(sConstraintName); SlKeysActTable.Add(SlKeysAct.Strings[i]); SlKeysForeignTable.Add(SlKeysFor.Strings[i]); SlForeignKeyTable.Add(sForeignTable); end; end; Next; end; finally FreeAndNil(SlKeysAct); FreeAndNil(SlKeysFor); end; end; end; end; finally FreeAndNil(MyRecordQuery); end; finally FreeAndNil(MySelectQuery); end; end; procedure TForm1.BStartClick(Sender: TObject); var SlForeignKeyName, SlKeysActTable, SlKeysForeignTable, SlForeignKeyTable: TStringList; i: Integer; begin try SlForeignKeyName := TStringList.Create; SlKeysActTable := TStringList.Create; SlKeysForeignTable := TStringList.Create; SlForeignKeyTable := TStringList.Create; GetForeignKeys('Kundendaten', // Tabel name ADOConnection1, // ADOConnection SlForeignKeyName, // Foreign Key Name SlKeysActTable, SlKeysForeignTable, SlForeignKeyTable); for i := 0 to (SlForeignKeyName.Count - 1) do begin if i > 0 then begin Memo1.Lines.Add(''); end; Memo1.Lines.Add(SlForeignKeyName.Strings[i]); Memo1.Lines.Add(SlKeysActTable.Strings[i]); Memo1.Lines.Add(SlKeysForeignTable.Strings[i]); Memo1.Lines.Add(SlForeignKeyTable.Strings[i]); end; finally FreeAndNil(SlForeignKeyName); FreeAndNil(SlKeysActTable); FreeAndNil(SlKeysForeignTable); FreeAndNil(SlForeignKeyTable); end; end; end. |