Oracle转义符号

CREATE OR REPLACE PROCEDURE proc_ct_11(
  quhao in varchar
)
IS
  CURSOR ct_filter
  IS
      SELECT        br_number, br_company
              from ct_lsb
      FOR UPDATE OF br_count;

  v_br_number    VARCHAR2 (128);
  v_count        PLS_INTEGER;
  v_error        VARCHAR2 (150);
  v_br_company  VARCHAR2 (150);
  sub_br_number  VARCHAR2 (128);
  v_exit   int;
BEGIN
  OPEN ct_filter;
  LOOP                                         
    FETCH ct_filter INTO v_br_number, v_br_company;
EXIT WHEN ct_filter%NOTFOUND;
IF instr(v_br_number,'/')=0
  THEN
v_br_number:=SUBSTR (v_br_number, 6,7);
    EXECUTE IMMEDIATE 'SELECT COUNT (*) INTO v_count from br_'||quhao ||' WHERE instr(br_number, '||v_br_number||')>0 OR br_company ='|| v_br_company;
     
……

最后的 EXECUTE IMMEDIATE 那个sql语句 由于v_br_number，v_br_company是varchar型 要执行的sql要加单引号 请问要怎么写才对？{{----}