Backup DataBase Users and Roles

Use the below script to back up users, roles, schema and secure permission from a DB.
1) Update the @DBNAME with the DB Name which you want to script out.
2) Update @STORAGEDBNAME with the DB Nam where you want to store the 
result.
3) Execute script in the same DB and get the result.

--select * from MSDB.DBO.TEMP_TABLE_FOR_USERS
DECLARE @DBNAME VARCHAR(50),
  @STORAGEDBNAME VARCHAR(50)
SET @DBNAME='<Your DB Name>'
SET @STORAGEDBNAME='MSDB'

SET NOCOUNT ON
DECLARE @CMD VARCHAR(350)
SET @CMD= 'IF  EXISTS (SELECT * FROM '+@STORAGEDBNAME+'.sys.objects WHERE object_id = OBJECT_ID('''+@STORAGEDBNAME+'.[dbo].[TEMP_TABLE_FOR_USERS]'')
   AND type in (''U''))
   DROP TABLE '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS
   CREATE TABLE '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS
   ([COMMAND] TEXT)'
   
EXEC (@CMD)
CREATE TABLE #TEMP
 (   NUMBER INT IDENTITY(1,1) NOT NULL, 
  USERNAME VARCHAR(100),
  ROLENAME VARCHAR(100),
  ISNTGROUP INT
 )
CREATE TABLE #TEMP1
 (   NUMBER INT IDENTITY(1,1) NOT NULL, 
  OBJECTNAME VARCHAR(100),
  TYPE_DESC VARCHAR(100),
  PERMISSION_NAME VARCHAR(100),
  STATE_DESC VARCHAR(100),
  USERNAME VARCHAR(100),
  SCHEMANAME VARCHAR(100)
 )
CREATE TABLE #TEMP2
 (   NUMBER INT IDENTITY(1,1) NOT NULL, 
  USERNAME VARCHAR(100),ISNTGROUP INT
  )

DECLARE @CM VARCHAR(100)
SET @CM='INSERT INTO '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS SELECT ''USE '+@DBNAME+''''
EXEC (@CM)

DECLARE @CMD1 VARCHAR(500),
@USER INT,
@USERNAME VARCHAR(50)

SET @CMD1= 'SELECT U.NAME , G.NAME ,U.ISNTGROUP
            FROM '+ @DBNAME+'.DBO.SYSUSERS U,' +@DBNAME+'.DBO.SYSUSERS G,' +@DBNAME+'.DBO.SYSMEMBERS M
            WHERE   G.UID = M.GROUPUID
            AND G.ISSQLROLE = 1 AND U.UID = M.MEMBERUID AND U.NAME<>''dbo'''
INSERT INTO #TEMP
EXEC (@CMD1)

INSERT INTO #TEMP2
SELECT DISTINCT USERNAME,ISNTGROUP FROM #TEMP
DECLARE @CMD2 VARCHAR(5000)
SET @CMD2=  'DECLARE @COUNT INT,@USER INT,@ISNT INT
     SET @COUNT=1 SELECT @USER=COUNT(*) FROM #TEMP2 
     WHILE @USER>=@COUNT
     BEGIN
       SELECT @ISNT= ISNTGROUP FROM #TEMP2 WHERE NUMBER=@COUNT
       IF @ISNT=0
       BEGIN
      INSERT INTO '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS
      SELECT ''IF NOT EXISTS (SELECT * FROM SYS.DATABASE_PRINCIPALS WHERE NAME = ''''''+USERNAME+'''''')
      CREATE USER [''+USERNAME+''] FOR LOGIN ['' +USERNAME +''] WITH DEFAULT_SCHEMA=[DBO]'' FROM #TEMP2
      WHERE NUMBER=@COUNT 
      END
      ELSE
      BEGIN
      INSERT INTO '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS
      SELECT ''IF NOT EXISTS (SELECT * FROM SYS.DATABASE_PRINCIPALS WHERE NAME = ''''''+USERNAME+'''''')
      CREATE USER [''+USERNAME+''] FOR LOGIN ['' +USERNAME +''] '' FROM #TEMP2
      WHERE NUMBER=@COUNT 
      END
      SET @COUNT=@COUNT+1
     END'
EXEC (@CMD2)
--SELECT @CMD2
-------------------- Schema Starts Here ------------------

CREATE TABLE #TEMP3
 (   NUMBER INT IDENTITY(1,1) NOT NULL, 
  SCHEMANAME VARCHAR(100)
 )
INSERT INTO #TEMP3 SELECT NAME FROM SYS.SCHEMAS WHERE [SCHEMA_ID] BETWEEN 5 AND 16383


DECLARE @CMD5 VARCHAR(5000)
SET @CMD5= 'DECLARE @SCHEMA INT,
     @COUNT3 INT
   SET @COUNT3=1
   SELECT @SCHEMA=COUNT(SCHEMANAME) FROM #TEMP3
   WHILE @SCHEMA>=@COUNT3
    BEGIN
    INSERT INTO '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS
      SELECT ''IF NOT EXISTS (SELECT * FROM SYS.SCHEMAS WHERE NAME = ''''''+SCHEMANAME+'''''')
      EXEC SYS.SP_EXECUTESQL N''''CREATE SCHEMA [''+SCHEMANAME+''] AUTHORIZATION ['' +SCHEMANAME +'']'''''' FROM #TEMP3
      WHERE NUMBER=@COUNT3 SET @COUNT3=@COUNT3+1
    END'
     
     
EXEC (@CMD5)

-------------------- User Role Starts Here ---------------
DECLARE @CMD3 VARCHAR(5000)
SET @CMD3= 'DECLARE @ROLE INT,
     @COUNT2 INT
   SET @COUNT2=1
   SELECT @ROLE=COUNT(ROLENAME) FROM #TEMP
   WHILE @ROLE>=@COUNT2
    BEGIN
     INSERT INTO '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS SELECT ''EXEC sp_addrolemember ''''''+ROLENAME+ '''''' ,''''''+ USERNAME+'''''''' FROM #TEMP 
     WHERE NUMBER=@COUNT2 SET @COUNT2=@COUNT2+1 
    END'
 
EXEC (@CMD3)

--------------------- Secure Permission Starts Here ---------------
INSERT INTO #TEMP1
SELECT O.NAME COLLATE LATIN1_GENERAL_CI_AS_KS_WS AS OBJECTNAME ,TYPE_DESC,
PERMISSION_NAME,STATE_DESC,U.NAME AS USERNAME,S.NAME AS SCHEMANAME
FROM SYS.DATABASE_PERMISSIONS P
INNER JOIN SYS.OBJECTS O ON O.OBJECT_ID=MAJOR_ID
INNER JOIN SYSUSERS U ON U.UID=P.GRANTEE_PRINCIPAL_ID
INNER JOIN SYS.SCHEMAS S ON O.SCHEMA_ID=S.SCHEMA_ID
WHERE TYPE_DESC <>'SYSTEM_TABLE'

DECLARE @CMD4 VARCHAR(5000)
SET @CMD4= 'DECLARE @SECUR INT,
     @COUNT1 INT
   SET @COUNT1=1
   SELECT @SECUR=COUNT(*) FROM #TEMP1
   WHILE @SECUR>=@COUNT1
    BEGIN
     INSERT INTO '+@STORAGEDBNAME+'.DBO.TEMP_TABLE_FOR_USERS SELECT ''''+STATE_DESC+'' ''+PERMISSION_NAME+'' ON ''+SCHEMANAME+''.''+OBJECTNAME+''  TO [''+USERNAME +'']''FROM #TEMP1 
     WHERE NUMBER=@COUNT1 SET @COUNT1=@COUNT1+1
    END'
EXEC (@CMD4)

-------------------- Final Output ---------------
DROP TABLE #TEMP
DROP TABLE #TEMP1
DROP TABLE #TEMP2
DROP TABLE #TEMP3
SET NOCOUNT OFF