Postgres - Stored procedure XML conversion

can you provide your input data and expected output. These functions are not available in postgresql.

This is the SQL server procedure i am trying to convert. Depending on the @GETBY values, i am taking certain action

CREATE PROCEDURE [dbo].[usp_SSOUser]
@GETBY VARCHAR(30) = NULL,
@EID VARCHAR(30) = NULL,
@FRST_NM VARCHAR(255) = NULL,
@LAST_NM VARCHAR(255) = NULL,
@MOD_NM VARCHAR(30) = NULL,
@SSO_USER_ID NUMERIC(12,0) = NULL,
@CRET_NM VARCHAR(30) = NULL,
@CRET_TS DATETIME = NULL,
@ACTV_IND NUMERIC(1,0) = NULL,
@ROLES XML = NULL
AS
SET NOCOUNT ON;
BEGIN TRANSACTION
      BEGIN TRY
            IF(UPPER(@GETBY)='GETUSERS')
            BEGIN
                  SELECT SU.SSO_USER_ID AS User_ID, SU.ACTV_IND AS Active,
                        LTRIM(SU.LAST_NM) +', '+  ltrim(SU.FRST_NM) AS  Name,
                        UPPER(ltrim(SU.EID)) AS EnterpriseID
                              FROM  SSO_USER SU
                              ORDER BY SU.ACTV_IND DESC, upper(SU.LAST_NM)
            END
            ELSE IF(UPPER(@GETBY)='GETROLES')
            BEGIN
                  SELECT SSO_ROLE_NM, SSO_ROLE_ID
                        FROM  SSO_ROLE WHERE ACTV_IND = 1
            END
            ELSE IF(UPPER(@GETBY)='GETXREF')
            BEGIN
                  SELECT XUR.SSO_USER_ID,XUR.SSO_ROLE_ID,SR.SSO_ROLE_NM
                        FROM SSO_XREF_USER_ROLE XUR,SSO_ROLE SR
                        WHERE XUR.SSO_ROLE_ID = SR.SSO_ROLE_ID AND
                              XUR.ACTV_IND = 1 AND SR.ACTV_IND = 1
            END
            ELSE IF(UPPER(@GETBY)='DUPLICATECHECK')
            BEGIN
                  SELECT count(*) FROM SSO_USER WHERE EID= @EID
            END
            ELSE IF(UPPER(@GETBY)='UPDUSER')
            BEGIN
                  update  SSO_USER set EID = @EID, FRST_NM = @FRST_NM,
                        LAST_NM = @LAST_NM, MOD_NM = @MOD_NM
                        where SSO_USER_ID = @SSO_USER_ID
            END
            ELSE IF(UPPER(@GETBY)='INSUSER')
            BEGIN
                  INSERT INTO SSO_USER(EID, FRST_NM, LAST_NM, ACTV_IND, CRET_NM, MOD_NM,CRET_TS)
                        VALUES (@EID,@FRST_NM,@LAST_NM,1,@CRET_NM,@MOD_NM,@CRET_TS)
            END
            ELSE IF(UPPER(@GETBY)='ACTIVATE')
            BEGIN
                  UPDATE SSO_USER SET ACTV_IND = 1, MOD_NM = @CRET_NM
                        where SSO_USER_ID = @SSO_USER_ID
            END
            ELSE IF(UPPER(@GETBY)='DEACTIVATE')
            BEGIN
                  UPDATE SSO_USER SET ACTV_IND = 0, MOD_NM = @CRET_NM
                        where SSO_USER_ID = @SSO_USER_ID
            END
            ELSE IF(UPPER(@GETBY)='UPDATEROLEACCESS')
            BEGIN
            DECLARE @idoc int;
            EXEC sp_xml_preparedocument @idoc OUTPUT, @ROLES;
                  UPDATE SSO_XREF_USER_ROLE SET ACTV_IND=1 WHERE
                  (CONVERT(VARCHAR,SSO_USER_ID)+CONVERT(VARCHAR,SSO_ROLE_ID)) IN
                  (SELECT CONVERT(VARCHAR,X.SSO_USER_ID)+CONVERT(VARCHAR,X.SSO_ROLE_ID) FROM
                        (SELECT XUR.SSO_USER_ID,SR.SSO_ROLE_ID FROM SSO_XREF_USER_ROLE XUR
                              JOIN SSO_ROLE SR ON XUR.SSO_ROLE_ID=SR.SSO_ROLE_ID WHERE
                              SR.SSO_ROLE_NM IN
                              (SELECT RoleName FROM
                                    OPENXML(@idoc, '/DocumentElement/UpdateRoles', 2)
                                          WITH (RoleName  varchar(100),
                                                      RoleStatus  numeric(1,0))
                                                      WHERE RoleStatus=1))AS X)
                                                      
                  UPDATE SSO_XREF_USER_ROLE SET ACTV_IND=0 WHERE
                  (CONVERT(VARCHAR,SSO_USER_ID)+CONVERT(VARCHAR,SSO_ROLE_ID)) IN
                  (SELECT CONVERT(VARCHAR,X.SSO_USER_ID)+CONVERT(VARCHAR,X.SSO_ROLE_ID) FROM
                        (SELECT XUR.SSO_USER_ID,SR.SSO_ROLE_ID FROM SSO_XREF_USER_ROLE XUR
                              JOIN SSO_ROLE SR ON XUR.SSO_ROLE_ID=SR.SSO_ROLE_ID WHERE
                              SR.SSO_ROLE_NM IN
                              (SELECT RoleName FROM
                                    OPENXML(@idoc, '/DocumentElement/UpdateRoles', 2)
                                          WITH (RoleName  varchar(100),
                                                      RoleStatus  numeric(1,0))
                                                      WHERE RoleStatus=0))AS X)
                  INSERT INTO SSO_XREF_USER_ROLE(SSO_USER_ID,SSO_ROLE_ID,ACTV_IND,CRET_NM,CRET_TS)
                  SELECT X.SSO_USER_ID,X.SSO_ROLE_ID,1,@CRET_NM,GETDATE() FROM
                        (SELECT XUR.SSO_USER_ID,SR.SSO_ROLE_ID FROM SSO_XREF_USER_ROLE XUR
                              JOIN SSO_ROLE SR ON XUR.SSO_ROLE_ID=SR.SSO_ROLE_ID WHERE
                              SR.SSO_ROLE_NM IN
                              (SELECT RoleName FROM
                                    OPENXML(@idoc, '/DocumentElement/UpdateRoles', 2)
                                          WITH (RoleName  varchar(100),
                                                      RoleStatus  numeric(1,0))
                                                      ))AS X
                                                      WHERE CONVERT(VARCHAR,X.SSO_USER_ID)+CONVERT(VARCHAR,X.SSO_ROLE_ID) NOT IN
                                                            (SELECT CONVERT(VARCHAR,SSO_USER_ID)+CONVERT(VARCHAR,SSO_ROLE_ID)
                                                                  FROM SSO_XREF_USER_ROLE WHERE ACTV_IND=1)
                                                                  
                                                                  
                                                                              
                                                                  
            END
      END TRY
      BEGIN CATCH
            IF @@TRANCOUNT > 0
                  ROLLBACK TRANSACTION;
      END CATCH
IF @@TRANCOUNT > 0
      COMMIT;

Have not received any update this? What is the equivalent for this code in Post gres for SP_XML_PREPAREDOCUMENT and also for openxml

EXEC sp_xml_preparedocument @idoc OUTPUT, @ROLES;
                  UPDATE SSO_XREF_USER_ROLE SET ACTV_IND=1 WHERE
                  (CONVERT(VARCHAR,SSO_USER_ID)+CONVERT(VARCHAR,SSO_ROLE_ID)) IN
                  (SELECT CONVERT(VARCHAR,X.SSO_USER_ID)+CONVERT(VARCHAR,X.SSO_ROLE_ID) FROM
                        (SELECT XUR.SSO_USER_ID,SR.SSO_ROLE_ID FROM SSO_XREF_USER_ROLE XUR
                              JOIN SSO_ROLE SR ON XUR.SSO_ROLE_ID=SR.SSO_ROLE_ID WHERE
                              SR.SSO_ROLE_NM IN
                              (SELECT RoleName FROM
                                    OPENXML(@idoc, '/DocumentElement/UpdateRoles', 2)
                                          WITH (RoleName  varchar(100),
                                                      RoleStatus  numeric(1,0))
                                                      WHERE RoleStatus=1))AS X)

This ( SP_XML_PREPAREDOCUMENT )  is not available in Postgre SQL

Is PostgreSQL we can use xpath and Unnest for XML parsing and data extraction.

Please go through the XML documentation from postgreSQL site

https://www.postgresql.org/docs/9.1/static/functions-xml.html

Appreciate if i can get the exact replacement for these SQLServer in PostgresSQL

EXEC sp_xml_preparedocument @idoc OUTPUT, @ROLES;
  OPENXML(@idoc, '/DocumentElement/UpdateRoles', 2)
                                          WITH (RoleName  varchar(100),
                                                      RoleStatus  numeric(1,0))
                                                      WHERE RoleStatus=1))AS X)