refactor: outsource queries from GetRowCount into TSqlProvider

This required to introduce a third version of TSqlProvider.GetSql which works with named parameters packed into a TStringMap
2026-03-13 09:24:25 +08:00 · 2026-02-16 20:45:23 +01:00
parent 277c0a969a
commit 14f5468af2
5 changed files with 72 additions and 60 deletions
--- a/source/dbconnection.pas
+++ b/source/dbconnection.pas
@@ -166,6 +166,7 @@ type
      FCreateCodeLoaded: Boolean;
      FWasSelected: Boolean;
      FConnection: TDBConnection;
+      FMap: TStringMap;
      function GetObjType: String;
      function GetImageIndex: Integer;
      function GetOverlayImageIndex: Integer;
@@ -185,6 +186,7 @@ type

      NodeType, GroupType: TListNodeType;
      constructor Create(OwnerConnection: TDBConnection);
+      destructor Destroy;
      procedure Assign(Source: TPersistent); override;
      procedure UnloadDetails;
      procedure Drop;
@@ -197,6 +199,7 @@ type
      function RowCount(Reload: Boolean; ForceExact: Boolean=False): Int64;
      function GetCreateCode: String; overload;
      function GetCreateCode(RemoveAutoInc, RemoveDefiner: Boolean): String; overload;
+      function AsStringMap: TStringMap;
      property ObjType: String read GetObjType;
      property ImageIndex: Integer read GetImageIndex;
      property OverlayImageIndex: Integer read GetOverlayImageIndex;
@@ -417,9 +420,9 @@ type
  TDBLogEvent = procedure(Msg: String; Category: TDBLogCategory=lcInfo; Connection: TDBConnection=nil) of object;
  TDBEvent = procedure(Connection: TDBConnection; Database: String) of object;
  TDBDataTypeArray = Array of TDBDataType;
-  TFeatureOrRequirement = (frSrid, frTimezoneVar, frTemporalTypesFraction, frKillQuery,
-    frLockedTables, frShowCreateTrigger, frShowWarnings,
-    frShowCharset, frIntegerDisplayWidth, frShowFunctionStatus, frShowProcedureStatus,
+  TFeatureOrRequirement = (frSrid, frTimezoneVar, frTemporalTypesFraction,
+    frShowCreateTrigger, frShowWarnings,
+    frIntegerDisplayWidth, frShowFunctionStatus, frShowProcedureStatus,
    frShowTriggers, frShowEvents, frColumnDefaultParentheses,
    frHelpKeyword, frEditVariables, frCreateView, frCreateProcedure, frCreateFunction,
    frCreateTrigger, frCreateEvent, frInvisibleColumns, frCompressedColumns);
@@ -644,7 +647,6 @@ type
      function GetAllDatabases: TStringList; override;
      function GetTableEngines: TStringList; override;
      function GetCreateViewCode(Database, Name: String): String;
-      function GetRowCount(Obj: TDBObject; ForceExact: Boolean=False): Int64; override;
      procedure FetchDbObjects(db: String; var Cache: TDBObjectList); override;
    public
      constructor Create(AOwner: TComponent); override;
@@ -674,7 +676,6 @@ type
      function GetLastErrorCode: Cardinal; override;
      function GetLastErrorMsg: String; override;
      function GetAllDatabases: TStringList; override;
-      function GetRowCount(Obj: TDBObject; ForceExact: Boolean=False): Int64; override;
      procedure FetchDbObjects(db: String; var Cache: TDBObjectList); override;
    public
      constructor Create(AOwner: TComponent); override;
@@ -714,7 +715,6 @@ type
      function Ping(Reconnect: Boolean): Boolean; override;
      function GetCreateCode(Obj: TDBObject): String; override;
      function ConnectionInfo: TStringList; override;
-      function GetRowCount(Obj: TDBObject; ForceExact: Boolean=False): Int64; override;
      property LastRawResults: TPGRawResults read FLastRawResults;
      property RegClasses: TOidStringPairs read FRegClasses;
      function GetTableKeys(Table: TDBObject): TTableKeyList; override;
@@ -6621,11 +6621,8 @@ begin
        frTimezoneVar: Result := ServerVersionInt >= 40103;
        frTemporalTypesFraction: Result := (FParameters.IsMariaDB and (ServerVersionInt >= 50300)) or
          (FParameters.IsMySQL(True) and (ServerVersionInt >= 50604));
-        frKillQuery: Result := (not FParameters.IsMySQLonRDS) and (ServerVersionInt >= 50000);
-        frLockedTables: Result := (not FParameters.IsProxySQLAdmin) and (ServerVersionInt >= 50124);
        frShowCreateTrigger: Result := ServerVersionInt >= 50121;
        frShowWarnings: Result := ServerVersionInt >= 40100;
-        frShowCharset: Result := ServerVersionInt >= 40100;
        frIntegerDisplayWidth: Result := (FParameters.IsMySQL(True) and (ServerVersionInt < 80017)) or
          (not FParameters.IsMySQL(True));
        frShowFunctionStatus: Result := (not Parameters.IsProxySQLAdmin) and (ServerVersionInt >= 50000);
@@ -6651,59 +6648,20 @@ end;

 function TDBConnection.GetRowCount(Obj: TDBObject; ForceExact: Boolean=False): Int64;
 var
-  Rows: String;
+  Rows, QueryApprox, QueryExact: String;
+  RowsColumn: Integer;
 begin
  // Get row number from a table
-  Rows := GetVar('SELECT COUNT(*) FROM '+QuotedDbAndTableName(Obj.Database, Obj.Name), 0);
-  Result := MakeInt(Rows);
-end;
-
-
-function TMySQLConnection.GetRowCount(Obj: TDBObject; ForceExact: Boolean=False): Int64;
-var
-  Rows: String;
-begin
-  // Get row number from a mysql table
-  if Parameters.IsProxySQLAdmin or ForceExact then begin
-    Result := inherited
+  QueryApprox := FSqlProvider.GetSql(qGetRowCountApprox, Obj.AsStringMap);
+  if QueryApprox.IsEmpty or ForceExact then begin
+    QueryExact := FSqlProvider.GetSql(qGetRowCountExact, Obj.AsStringMap);
+    Rows := GetVar(QueryExact);
  end
  else begin
-    Rows := GetVar('SHOW TABLE STATUS LIKE '+EscapeString(Obj.Name), 'Rows');
-    Result := MakeInt(Rows);
+    // This is ugly: in MySQL 4.x we only have SHOW TABLE STATUS, which cannot be limited to the "Rows" column
+    RowsColumn := IfThen(QueryApprox.StartsWith('SHOW ', True), 4, 0);
+    Rows := GetVar(QueryApprox, RowsColumn);
  end;
-end;
-
-
-function TAdoDBConnection.GetRowCount(Obj: TDBObject; ForceExact: Boolean=False): Int64;
-var
-  Rows: String;
-begin
-  // Get row number from a mssql table
-  if (ServerVersionInt < 900) or ForceExact then begin
-    Result := inherited
-  end
-  else begin
-    Rows := GetVar('SELECT SUM('+QuoteIdent('rows')+') FROM '+QuoteIdent('sys')+'.'+QuoteIdent('partitions')+
-      ' WHERE '+QuoteIdent('index_id')+' IN (0, 1)'+
-      ' AND '+QuoteIdent('object_id')+' = object_id('+EscapeString(Obj.Database+'.'+Obj.Schema+'.'+Obj.Name)+')'
-      );
-    Result := MakeInt(Rows);
-  end;
-end;
-
-
-function TPgConnection.GetRowCount(Obj: TDBObject; ForceExact: Boolean=False): Int64;
-var
-  Rows: String;
-begin
-  // Get row number from a postgres table
-  Rows := GetVar('SELECT '+QuoteIdent('reltuples')+'::bigint FROM '+QuoteIdent('pg_class')+
-    ' LEFT JOIN '+QuoteIdent('pg_namespace')+
-    '   ON ('+QuoteIdent('pg_namespace')+'.'+QuoteIdent('oid')+' = '+QuoteIdent('pg_class')+'.'+QuoteIdent('relnamespace')+')'+
-    ' WHERE '+QuoteIdent('pg_class')+'.'+QuoteIdent('relkind')+'='+EscapeString('r')+
-    ' AND '+QuoteIdent('pg_namespace')+'.'+QuoteIdent('nspname')+'='+EscapeString(Obj.Database)+
-    ' AND '+QuoteIdent('pg_class')+'.'+QuoteIdent('relname')+'='+EscapeString(Obj.Name)
-    );
  Result := MakeInt(Rows);
 end;

@@ -10183,6 +10141,13 @@ begin
  FCreateCodeLoaded := False;
  FWasSelected := False;
  FConnection := OwnerConnection;
+  FMap := TStringMap.Create;
+end;
+
+destructor TDBObject.Destroy;
+begin
+  FMap.Free;
+  inherited;
 end;


@@ -10532,6 +10497,20 @@ begin
  Result.Assign(CheckConstraintsInCache);
 end;

+function TDBObject.AsStringMap: TStringMap;
+begin
+  FMap.Clear;
+  FMap.Add('EscapedName', FConnection.EscapeString(Name));
+  FMap.Add('EscapedSchema', FConnection.EscapeString(Schema));
+  FMap.Add('EscapedDatabase', FConnection.EscapeString(Database));
+  FMap.Add('EscapedDbSchemaName', FConnection.EscapeString(Database+'.'+Schema+'.'+Name));
+  FMap.Add('QuotedDatabase', QuotedDatabase);
+  FMap.Add('QuotedName', QuotedName);
+  FMap.Add('QuotedDbAndTableName', QuotedDbAndTableName);
+  Result := FMap;
+end;
+
+


 { *** TTableColumn }
--- a/source/dbstructures.mssql.pas
+++ b/source/dbstructures.mssql.pas
@@ -476,6 +476,11 @@ begin
      ''''' AS "Default", '''' AS "Compiled", '+
      '1 AS "Sortlen"';
    qGetCharsets: Result := 'SELECT name AS Charset, description AS Description FROM master.sys.syscharsets';
+    qGetRowCountApprox: Result := IfThen(
+      FServerVersion >= 900,
+      'SELECT SUM("rows") FROM "sys"."partitions" WHERE "index_id" IN (0, 1) AND "object_id" = object_id(:EscapedDbSchemaName)',
+      ''
+      );
    else Result := inherited;
  end;
 end;
--- a/source/dbstructures.mysql.pas
+++ b/source/dbstructures.mysql.pas
@@ -3316,6 +3316,11 @@ begin
      'SHOW CHARSET',
      ''
      );
+    qGetRowCountApprox: Result := IfThen(
+      FNetType <> ntMySQL_ProxySQLAdmin,
+      'SHOW TABLE STATUS LIKE :EscapedName',
+      ''
+      );
    else Result := inherited;
  end;
 end;
--- a/source/dbstructures.pas
+++ b/source/dbstructures.pas
@@ -36,6 +36,7 @@ type
  TNetTypeLibs = TDictionary<TNetType, TStringList>;

  // SQL query ids and provider
+  TStringMap = TDictionary<string,string>;
  TQueryId = (qDatabaseTable, qDatabaseTableId, qDatabaseDrop,
    qDbObjectsTable, qDbObjectsCreateCol, qDbObjectsUpdateCol, qDbObjectsTypeCol,
    qEmptyTable, qRenameTable, qRenameView, qCurrentUserHost, qLikeCompare,
@@ -45,7 +46,7 @@ type
    qUSEQuery, qKillQuery, qKillProcess,
    qFuncLength, qFuncCeil, qFuncLeft, qFuncNow, qFuncLastAutoIncNumber,
    qLockedTables, qDisableForeignKeyChecks, qEnableForeignKeyChecks,
-    qOrderAsc, qOrderDesc,
+    qOrderAsc, qOrderDesc, qGetRowCountExact, qGetRowCountApprox,
    qForeignKeyDrop, qGetTableColumns, qGetCollations, qGetCollationsExtended, qGetCharsets);
  TSqlProvider = class
    strict protected
@@ -54,8 +55,12 @@ type
    public
      constructor Create(ANetType: TNetType);
      function Has(AId: TQueryId): Boolean;
+      // Base version, just returns the original SQL string
      function GetSql(AId: TQueryId): string; overload; virtual;
+      // Version for simple strings passed to Format()
      function GetSql(AId: TQueryId; const Args: array of const): string; overload;
+      // Version for named parameters
+      function GetSql(AId: TQueryId; NamedParameters: TStringMap): string; overload;
      property ServerVersion: Integer read FServerVersion write FServerVersion;
  end;

@@ -203,6 +208,7 @@ begin
    qForeignKeyEventAction: Result := 'RESTRICT,CASCADE,SET NULL,NO ACTION';
    qOrderAsc: Result := 'ASC';
    qOrderDesc: Result := 'DESC';
+    qGetRowCountExact: Result := 'SELECT COUNT(*) FROM :QuotedDbAndTableName';
    else Result := '';
  end;
 end;
@@ -210,10 +216,22 @@ end;
 function TSqlProvider.GetSql(AId: TQueryId; const Args: array of const): string;
 begin
  Result := GetSql(AId);
-  if not Result.IsEmpty then
-    Result := Format(Result, Args);
+  if Result.IsEmpty then
+    Exit;
+  Result := Format(Result, Args);
 end;

+function TSqlProvider.GetSql(AId: TQueryId; NamedParameters: TStringMap): string;
+var
+  Key: String;
+begin
+  Result := GetSql(AId);
+  if Result.IsEmpty then
+    Exit;
+  for Key in NamedParameters.Keys do begin
+    Result := StringReplace(Result, ':'+Key, NamedParameters[Key], [rfReplaceAll]);
+  end;
+end;



--- a/source/dbstructures.postgresql.pas
+++ b/source/dbstructures.postgresql.pas
@@ -709,6 +709,11 @@ begin
      '(SELECT conforencoding AS enc FROM pg_catalog.pg_conversion '+
      '  UNION '+
      '  SELECT contoencoding AS enc FROM pg_catalog.pg_conversion) AS x';
+    qGetRowCountApprox: Result := 'SELECT reltuples::bigint FROM pg_class'+
+      ' LEFT JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace'+
+      ' WHERE pg_class.relkind=''r'''+
+      '   AND pg_namespace.nspname=:EscapedDatabase'+
+      '   AND pg_class.relname=:EscapedName';
    else Result := inherited;
  end;
 end;