USE [Database Name];

DECLARE @TableName  VARCHAR(128)
DECLARE @SchemaName VARCHAR(128)
DECLARE @SQL	    VARCHAR(1000)

CREATE TABLE #tableList
	(
	 SchemaName	VARCHAR(128)
	,TableName	VARCHAR(128)
	,PrimaryKey	BIT
	);

INSERT INTO #tableList
	SELECT SCHEMA_NAME(SCHEMA_ID) AS SchemaName
		,name AS TableName
		,0 -- No Primary Key
	FROM sys.tables
	WHERE OBJECTPROPERTY(OBJECT_ID,'TableHasPrimaryKey') = 0
	ORDER BY SchemaName, TableName

WHILE (SELECT COUNT(*) FROM #tableList WHERE PrimaryKey = 0) > 0
	BEGIN
		SELECT TOP 1 @TableName = TableName
			, @SchemaName = SchemaName
		FROM #tableList
		WHERE PrimaryKey = 0;

			SET @SQL = 'ALTER TABLE [' +@SchemaName + '].[' +@TableName + '] ADD [RowID] INT IDENTITY(1,1)'
			EXEC (@SQL)
			IF @@ERROR<>0 PRINT @SQL

		UPDATE #tableList
		SET PrimaryKey = 1
		WHERE TableName = @TableName
		AND SchemaName = @SchemaName
	END

DROP TABLE #tableList;

USE [Database Name];

DECLARE @TableName  VARCHAR(128)
DECLARE @SchemaName VARCHAR(128)
DECLARE @SQL          VARCHAR(1000)

CREATE TABLE #tableList
      (
       SchemaName VARCHAR(128)
      ,TableName  VARCHAR(128)
      ,RowID      BIT
      );

INSERT INTO #tableList
      SELECT TABLE_SCHEMA AS SchemaName
      , TABLE_NAME AS TableName
      , 0
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COLUMN_NAME = 'RowID'
ORDER BY SchemaName, TableName

WHILE (SELECT COUNT(*) FROM #tableList WHERE RowID = 0) > 0
      BEGIN
            SELECT TOP 1 @TableName = TableName
                  , @SchemaName = SchemaName
            FROM #tableList
            WHERE RowID = 0;

                  SET @SQL = 'ALTER TABLE [' +@SchemaName + '].[' +@TableName + '] ADD CONSTRAINT PK_' +@SchemaName + '_' +@TableName + ' PRIMARY KEY NONCLUSTERED (RowID) ON [PRIMARY]'
                  EXEC (@SQL)
                  IF @@ERROR<>0 PRINT @SQL

            UPDATE #tableList
            SET RowID = 1
            WHERE TableName = @TableName
            AND SchemaName = @SchemaName
      END

DROP TABLE #tableList;