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* Implemented RETURNING clause as a way of updating fields

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git-svn-id: trunk@30463 -
This commit is contained in:
michael 2015-04-06 13:20:30 +00:00
parent 1427d94933
commit 9a807bdfe3
5 changed files with 157 additions and 21 deletions
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1
packages/fcl-db/src/base/dbconst.pas
View File

@ -122,6 +122,7 @@ Resourcestring
SErrRefreshNotSingleton = 'Refresh SQL resulted in multiple records: %d.';
SErrRefreshEmptyResult = 'Refresh SQL resulted in empty result set.';
SErrNoKeyFieldForRefreshClause = 'No key field found to construct refresh SQL WHERE clause';
SErrFailedToFetchReturningResult = 'Failed to fetch returning result';
Implementation

2
packages/fcl-db/src/sqldb/interbase/ibconnection.pp
View File

@ -180,7 +180,7 @@ constructor TIBConnection.Create(AOwner : TComponent);
begin
inherited;
FConnOptions := FConnOptions + [sqSupportParams] + [sqEscapeRepeat];
FConnOptions := FConnOptions + [sqSupportParams, sqEscapeRepeat, sqSupportReturning];
FBlobSegmentSize := 65535; //Shows we're using the maximum segment size
FDialect := INVALID_DATA;
ResetDatabaseInfo;

2
packages/fcl-db/src/sqldb/postgres/pqconnection.pp
View File

@ -274,7 +274,7 @@ constructor TPQConnection.Create(AOwner : TComponent);
begin
inherited;
FConnOptions := FConnOptions + [sqSupportParams, sqSupportEmptyDatabaseName, sqEscapeRepeat, sqEscapeSlash, sqImplicitTransaction];
FConnOptions := FConnOptions + [sqSupportParams, sqSupportEmptyDatabaseName, sqEscapeRepeat, sqEscapeSlash, sqImplicitTransaction,sqSupportReturning];
FieldNameQuoteChars:=DoubleQuotes;
VerboseErrors:=True;
FConnectionPool:=TThreadlist.Create;

101
packages/fcl-db/src/sqldb/sqldb.pp
View File

@ -138,7 +138,7 @@ type
{ TSQLConnection }
TConnOption = (sqSupportParams, sqSupportEmptyDatabaseName, sqEscapeSlash, sqEscapeRepeat, sqImplicitTransaction, sqLastInsertID);
TConnOption = (sqSupportParams, sqSupportEmptyDatabaseName, sqEscapeSlash, sqEscapeRepeat, sqImplicitTransaction, sqLastInsertID, sqSupportReturning);
TConnOptions= set of TConnOption;
TSQLConnectionOption = (scoExplicitConnect, scoApplyUpdatesChecksRowsAffected);
@ -172,11 +172,11 @@ type
// One day, this may be factored out to a TSQLResolver class.
// The following allow construction of update queries. They can be adapted as needed by descendents to fit the DB engine.
procedure AddFieldToUpdateWherePart(var sql_where: string; UpdateMode : TUpdateMode; F: TField); virtual;
function ConstructInsertSQL(Query: TCustomSQLQuery): string; virtual;
function ConstructUpdateSQL(Query: TCustomSQLQuery): string; virtual;
function ConstructInsertSQL(Query: TCustomSQLQuery; Var ReturningClause : Boolean): string; virtual;
function ConstructUpdateSQL(Query: TCustomSQLQuery; Var ReturningClause : Boolean): string; virtual;
function ConstructDeleteSQL(Query: TCustomSQLQuery): string; virtual;
function ConstructRefreshSQL(Query: TCustomSQLQuery; UpdateKind : TUpdateKind): string; virtual;
function InitialiseUpdateStatement(Query: TCustomSQLQuery; var qry: TCustomSQLStatement): TCustomSQLStatement;
function InitialiseUpdateStatement(Query: TCustomSQLQuery; var qry: TCustomSQLQuery): TCustomSQLQuery;
procedure ApplyFieldUpdate(C : TSQLCursor; P: TSQLDBParam; F: TField; UseOldValue: Boolean); virtual;
// This is the call that updates a record, it used to be in TSQLQuery.
procedure ApplyRecUpdate(Query : TCustomSQLQuery; UpdateKind : TUpdateKind); virtual;
@ -402,7 +402,7 @@ type
{ TCustomSQLQuery }
TSQLQueryOption = (sqoKeepOpenOnCommit, sqoAutoApplyUpdates, sqoAutoCommit, sqoCancelUpdatesOnRefresh);
TSQLQueryOption = (sqoKeepOpenOnCommit, sqoAutoApplyUpdates, sqoAutoCommit, sqoCancelUpdatesOnRefresh, sqoPreferRefresh);
TSQLQueryOptions = Set of TSQLQueryOption;
TCustomSQLQuery = class (TCustomBufDataset)
@ -433,7 +433,7 @@ type
FInsertQry,
FUpdateQry,
FDeleteQry : TCustomSQLStatement;
FDeleteQry : TCustomSQLQuery;
FSequence : TSQLSequence;
procedure FreeFldBuffers;
function GetParamCheck: Boolean;
@ -466,6 +466,7 @@ type
Function RefreshLastInsertID(Field: TField): Boolean; virtual;
Function NeedRefreshRecord (UpdateKind: TUpdateKind): Boolean; virtual;
Function RefreshRecord (UpdateKind: TUpdateKind) : Boolean; virtual;
Procedure ApplyReturningResult(Q : TCustomSQLQuery; UpdateKind : TUpdateKind);
Function Cursor : TSQLCursor;
Function LogEvent(EventType : TDBEventType) : Boolean;
Procedure Log(EventType : TDBEventType; Const Msg : String); virtual;
@ -1587,15 +1588,18 @@ begin
end;
function TSQLConnection.InitialiseUpdateStatement(Query : TCustomSQLQuery; var qry : TCustomSQLStatement): TCustomSQLStatement;
function TSQLConnection.InitialiseUpdateStatement(Query : TCustomSQLQuery; var qry : TCustomSQLQuery): TCustomSQLQuery;
begin
if not assigned(qry) then
begin
qry := TCustomSQLStatement.Create(nil);
qry := TCustomSQLQuery.Create(nil);
qry.ParseSQL := False;
qry.DataBase := Self;
qry.Transaction := Query.SQLTransaction;
qry.Unidirectional:=True;
qry.UsePrimaryKeyAsKey:=False;
qry.PacketRecords:=1;
end;
Result:=qry;
end;
@ -1620,16 +1624,19 @@ begin
end;
function TSQLConnection.ConstructInsertSQL(Query : TCustomSQLQuery) : string;
function TSQLConnection.ConstructInsertSQL(Query : TCustomSQLQuery; Var ReturningClause : Boolean) : string;
var x : integer;
sql_fields : string;
sql_values : string;
returning_fields : String;
F : TField;
begin
sql_fields := '';
sql_values := '';
returning_fields :='';
for x := 0 to Query.Fields.Count -1 do
begin
F:=Query.Fields[x];
@ -1638,37 +1645,60 @@ begin
sql_fields := sql_fields + FieldNameQuoteChars[0] + F.FieldName + FieldNameQuoteChars[1] + ',';
sql_values := sql_values + ':"' + F.FieldName + '",';
end;
if ReturningClause and (pfRefreshOnInsert in F.ProviderFlags) then
returning_fields :=returning_fields+FieldNameQuoteChars[0] + F.FieldName + FieldNameQuoteChars[1] + ',';
end;
if length(sql_fields) = 0 then
DatabaseErrorFmt(sNoUpdateFields,['insert'],self);
setlength(sql_fields,length(sql_fields)-1);
setlength(sql_values,length(sql_values)-1);
result := 'insert into ' + Query.FTableName + ' (' + sql_fields + ') values (' + sql_values + ')';
if ReturningClause then
begin
ReturningClause:=length(returning_fields) <> 0 ;
if ReturningClause then
begin
setlength(returning_fields,length(returning_fields)-1);
result:=Result+' returning '+returning_fields;
end;
end;
end;
function TSQLConnection.ConstructUpdateSQL(Query: TCustomSQLQuery): string;
function TSQLConnection.ConstructUpdateSQL(Query: TCustomSQLQuery; Var ReturningClause : Boolean): string;
var x : integer;
F : TField;
sql_set : string;
sql_where : string;
returning_fields : String;
begin
sql_set := '';
sql_where := '';
returning_fields :='';
for x := 0 to Query.Fields.Count -1 do
begin
F:=Query.Fields[x];
AddFieldToUpdateWherePart(sql_where,Query.UpdateMode,F);
if (pfInUpdate in F.ProviderFlags) and (not F.ReadOnly) then
sql_set := sql_set +FieldNameQuoteChars[0] + F.FieldName + FieldNameQuoteChars[1] +'=:"' + F.FieldName + '",';
if ReturningClause and (pfRefreshOnUpdate in F.ProviderFlags) then
returning_fields :=returning_fields+FieldNameQuoteChars[0] + F.FieldName + FieldNameQuoteChars[1] + ',';
end;
if length(sql_set) = 0 then DatabaseErrorFmt(sNoUpdateFields,['update'],self);
setlength(sql_set,length(sql_set)-1);
if length(sql_where) = 0 then DatabaseErrorFmt(sNoWhereFields,['update'],self);
result := 'update ' + Query.FTableName + ' set ' + sql_set + ' where ' + sql_where;
if ReturningClause then
begin
ReturningClause:=length(returning_fields) <> 0 ;
if ReturningClause then
begin
setlength(returning_fields,length(returning_fields)-1);
result:=Result+' returning '+returning_fields;
end;
end;
end;
@ -1737,24 +1767,27 @@ end;
procedure TSQLConnection.ApplyRecUpdate(Query: TCustomSQLQuery; UpdateKind: TUpdateKind);
var
qry : TCustomSQLStatement;
qry : TCustomSQLQuery;
s : string;
x : integer;
Fld : TField;
P : TParam;
B : Boolean;
B,ReturningClause : Boolean;
begin
qry:=Nil;
ReturningClause:=(sqSupportReturning in Connoptions) and not (sqoPreferRefresh in Query.Options);
case UpdateKind of
ukInsert : begin
s := trim(Query.FInsertSQL.Text);
if s = '' then s := ConstructInsertSQL(Query);
if s = '' then
s := ConstructInsertSQL(Query,ReturningClause);
qry := InitialiseUpdateStatement(Query,Query.FInsertQry);
end;
ukModify : begin
s := trim(Query.FUpdateSQL.Text);
if (s='') and (not assigned(Query.FUpdateQry) or (Query.UpdateMode<>upWhereKeyOnly)) then //first time or dynamic where part
s := ConstructUpdateSQL(Query);
s := ConstructUpdateSQL(Query,ReturningClause);
qry := InitialiseUpdateStatement(Query,Query.FUpdateQry);
end;
ukDelete : begin
@ -1762,11 +1795,12 @@ begin
if (s='') and (not assigned(Query.FDeleteQry) or (Query.UpdateMode<>upWhereKeyOnly)) then
s := ConstructDeleteSQL(Query);
qry := InitialiseUpdateStatement(Query,Query.FDeleteQry);
ReturningClause:=False;
end;
end;
if (s<>'') and (qry.SQL.Text<>s) then
qry.SQL.Text:=s; //assign only when changed, to avoid UnPrepare/Prepare
assert(qry.sql.Text<>'');
Assert(qry.sql.Text<>'');
for x:=0 to Qry.Params.Count-1 do
begin
P:=Qry.Params[x];
@ -1777,9 +1811,18 @@ begin
Fld:=Query.FieldByName(S);
ApplyFieldUpdate(Query.Cursor,P as TSQLDBParam,Fld,B);
end;
Qry.Execute;
if ReturningClause then
Qry.Open
else
Qry.Execute;
if (scoApplyUpdatesChecksRowsAffected in Options) and (Qry.RowsAffected<>1) then
begin
if ReturningClause then
Qry.Close;
DatabaseErrorFmt(SErrFailedToUpdateRecord, [Qry.RowsAffected], Query);
end;
if ReturningClause then
Query.ApplyReturningResult(Qry,UpdateKind);
end;
function TSQLConnection.RefreshLastInsertID(Query: TCustomSQLQuery; Field: TField): Boolean;
@ -2310,9 +2353,12 @@ function TCustomSQLQuery.NeedRefreshRecord(UpdateKind: TUpdateKind): Boolean;
Var
PF : TProviderFlag;
I : Integer;
DoReturning : Boolean;
begin
Result:=(FRefreshSQL.Count<>0);
if Not Result then
DoReturning:=(sqSupportReturning in SQLConnection.ConnOptions) and not (sqoPreferRefresh in Options);
if Not (Result or DoReturning) then
begin
PF:=RefreshFlags[UpdateKind];
I:=0;
@ -2374,6 +2420,25 @@ begin
end;
end;
procedure TCustomSQLQuery.ApplyReturningResult(Q: TCustomSQLQuery; UpdateKind : TUpdateKind);
Var
S : TDataSetState;
refreshFlag : TProviderFlag;
F : TField;
begin
RefreshFlag:=RefreshFlags[UpdateKind];
S:=SetTempState(dsRefreshFields);
try
For F in Fields do
if RefreshFlag in F.ProviderFlags then
F.Assign(Q.FieldByName(F.FieldName));
finally
RestoreState(S);
end;
end;
procedure TCustomSQLQuery.ApplyFilter;
begin

72
packages/fcl-db/tests/testsqldb.pas
View File

@ -54,6 +54,8 @@ type
Procedure TestRefreshSQLNoRecords;
Procedure TestFetchAutoInc;
procedure TestSequence;
procedure TestReturningInsert;
procedure TestReturningUpdate;
end;
{ TTestTSQLConnection }
@ -198,7 +200,7 @@ begin
Q := SQLDBConnector.Query;
Q.SQL.Text:='select * from FPDEV2';
Q.Options:=[sqoKeepOpenOnCommit];
Q.Options:=[sqoKeepOpenOnCommit,sqoPreferRefresh];
AssertEquals('PacketRecords forced to -1',-1,Q.PacketRecords);
Q.Open;
AssertEquals('Got all records',20,Q.RecordCount);
@ -402,6 +404,7 @@ begin
Transaction.Commit;
end;
Q:=SQLDBConnector.Query;
Q.OPtions:=Q.OPtions+[sqoPreferRefresh];
Q.SQL.Text:='select * from FPDEV2';
Q.InsertSQL.Text:='insert into FPDEV2 (id) values (:id)';
Q.RefreshSQL.Text:='SELECT a,b FROM FPDEV2 WHERE (id=:id)';
@ -440,6 +443,7 @@ begin
Q:=SQLDBConnector.Query;
Q.SQL.Text:='select * from FPDEV2';
Q.InsertSQL.Text:='insert into FPDEV2 (id) values (:id)';
Q.OPtions:=Q.OPtions+[sqoPreferRefresh];
Q.Open;
With Q.FieldByName('id') do
ProviderFlags:=ProviderFlags+[pfInKey];
@ -471,6 +475,7 @@ begin
Q:=SQLDBConnector.Query;
Q.SQL.Text:='select * from FPDEV2';
Q.InsertSQL.Text:='insert into FPDEV2 (id) values (:id)';
Q.OPtions:=Q.OPtions+[sqoPreferRefresh];
Q.Open;
With Q.FieldByName('id') do
ProviderFlags:=ProviderFlags+[pfInKey];
@ -497,6 +502,7 @@ begin
FMyQ:=SQLDBConnector.Query;
FMyQ.SQL.Text:='select * from FPDEV2';
FMyQ.InsertSQL.Text:='insert into FPDEV2 (id) values (:id)';
FMyQ.OPtions:=FMyQ.OPtions+[sqoPreferRefresh];
FMyQ.Open;
With FMyQ.FieldByName('id') do
ProviderFlags:=ProviderFlags-[pfInKey];
@ -521,6 +527,7 @@ begin
Transaction.Commit;
end;
FMyQ:=SQLDBConnector.Query;
FMyQ.OPtions:=FMyQ.OPtions+[sqoPreferRefresh];
FMyQ.SQL.Text:='select * from FPDEV2';
FMyQ.InsertSQL.Text:='insert into FPDEV2 (id) values (:id)';
FMyQ.RefreshSQL.Text:='select * from FPDEV2';
@ -547,6 +554,7 @@ begin
Transaction.Commit;
end;
FMyQ:=SQLDBConnector.Query;
FMyQ.OPtions:=FMyQ.OPtions+[sqoPreferRefresh];
FMyQ.SQL.Text:='select * from FPDEV2';
FMyQ.InsertSQL.Text:='insert into FPDEV2 (id) values (:id)';
FMyQ.RefreshSQL.Text:='select * from FPDEV2 where 1=2';
@ -647,6 +655,68 @@ begin
SQLDBConnector.CommitDDL;
end;
procedure TTestTSQLQuery.TestReturningInsert;
begin
with SQLDBConnector do
begin
if not (sqSupportReturning in Connection.ConnOptions) then
Ignore(STestNotApplicable);
ExecuteDirect('create table FPDEV2 (id integer not null, a varchar(10) default ''abcde'', b varchar(5) default ''fgh'', constraint PK_FPDEV2 primary key(id))');
if Transaction.Active then
Transaction.Commit;
ExecuteDirect('insert into FPDEV2 (id) values (123)');
if Transaction.Active then
Transaction.Commit;
end;
FMyQ:=SQLDBConnector.Query;
FMyQ.SQL.Text:='select * from FPDEV2';
// FMyQ.InsertSQL.Text:='insert into FPDEV2 (id) values (:id)';
FMyQ.Open;
With FMyQ.FieldByName('id') do
ProviderFlags:=ProviderFlags+[pfInKey];
With FMyQ.FieldByName('a') do
ProviderFlags:=ProviderFlags+[pfRefreshOnInsert];
With FMyQ.FieldByName('b') do
ProviderFlags:=[];
FMyQ.Insert;
FMyQ.FieldByName('id').AsInteger:=1;
FMyQ.Post;
FMyQ.ApplyUpdates;
AssertEquals('a updated','abcde',FMyQ.FieldByName('a').AsString);
AssertEquals('b not updated','',FMyQ.FieldByName('b').AsString);
end;
procedure TTestTSQLQuery.TestReturningUpdate;
begin
with SQLDBConnector do
begin
if not (sqSupportReturning in Connection.ConnOptions) then
Ignore(STestNotApplicable);
ExecuteDirect('create table FPDEV2 (id integer not null, a varchar(10) default ''abcde'', b varchar(5) default ''fgh'', constraint PK_FPDEV2 primary key(id))');
if Transaction.Active then
Transaction.Commit;
ExecuteDirect('insert into FPDEV2 (id) values (123)');
if Transaction.Active then
Transaction.Commit;
end;
FMyQ:=SQLDBConnector.Query;
FMyQ.SQL.Text:='select * from FPDEV2';
FMyQ.Open;
With FMyQ.FieldByName('id') do
ProviderFlags:=ProviderFlags+[pfInKey];
With FMyQ.FieldByName('b') do
ProviderFlags:=[pfRefreshOnUpdate]; // Do not update, just fetch new value
FMyQ.Edit;
FMyQ.FieldByName('a').AsString:='ccc';
FMyQ.Post;
SQLDBConnector.ExecuteDirect('update FPDEV2 set b=''123'' where id=123');
FMyQ.ApplyUpdates;
AssertEquals('a updated','ccc',FMyQ.FieldByName('a').AsString);
AssertEquals('b updated','123',FMyQ.FieldByName('b').AsString);
end;
{ TTestTSQLConnection }