Oracle bulk collect into 的几种用法

Posted 2020-11-06 薛文博

bulk collect 和 forall 联合应用写起来显得有些啰嗦，不过为了速度，多写两句又何妨

建立两个临时表

    create table T_TEST  
    (  
      TESTID      NUMBER(19) not null,  
      TESTNAME    VARCHAR2(512),  
      TESTTYPE    VARCHAR2(512),  
      TESTLEVEL   VARCHAR2(512),  
      ADDFLAG     VARCHAR2(512)  
    );  
    create table T_TEST2  
    (  
      TESTID      NUMBER(19) not null,  
      TESTNAME    VARCHAR2(512),  
      TESTTYPE    VARCHAR2(512),  
      TESTLEVEL   VARCHAR2(512),  
    );  

存储过程使用示例1：

    create or replace procedure FAST_UP_TEST is  
    TYPE TARR is table of T_TEST%ROWTYPE;  
    vvrr TARR;  
    CURSOR curr is select * from T_TEST where ADDFLAG=‘add‘;  
    begin  
      open curr;  
      loop  
        fetch curr bulk collect into vvrr limit 1000;  
        dbms_output.put_line(‘增加:‘||vvrr.count);  
        forall i in 1..vvrr.count  
          update T_TEST2  
          set TESTTYPE=vvrr(i).TESTTYPE,TESTLEVEL=vvrr(i).TESTLEVEL   
          where TESTNAME=vvrr(i).TESTNAME and TESTID=vvrr(i).TESTID;  
          commit;  
        exit when curr%NOTFOUND;  
      end loop;  
      close curr;  
    end;  

换一个方式使用示例（注意游标返回类型变化）：

create or replace procedure FAST_DEL_TEST is  
TYPE TARR is table of T_TEST.TESTID%TYPE;  
vvrr TARR;  
CURSOR curr is select TESTID from T_TEST where ADDFLAG=‘delete‘;  
begin  
  dbms_output.enable(90000);  
  open curr;  
  loop  
    fetch curr bulk collect into vvrr limit 1000;  
    dbms_output.put_line(‘delete T_TEST ‘||vvrr.count);  
    forall i in 1..vvrr.count  
      delete T_TEST2  
      where TESTID=vvrr(i);  
      commit;  
    exit when curr%NOTFOUND;  
  end loop;  
  close curr;  
end; 

多参数返回的另一种用法和动态sql运行办法

    create or replace procedure FAST_AD_TEST (  
      tabtest in VARCHAR2) is  
    TYPE TARR_ID is table of T_TEST.TESTID%TYPE;  
    TYPE TARR_NM is table of T_TEST.TESTNAME%TYPE;  
    TYPE TARR_TP is table of T_TEST.TESTTYPE%TYPE;  
    vvid TARR_ID;  
    vvnm TARR_NM;  
    vvtp TARR_TP;  
    CURSOR curr is select TESTID,TESTNAME,TESTTYPE from T_TEST where ADDFLAG=‘add‘;  
    CURSOR curd is select TESTID from T_TEST where ADDFLAG=‘delete‘;  
    begin  
      execute immediate ‘truncate table ‘||tabtest;  
      -- forall只能写一条sql。。。  
      open curr;  
      loop  
        fetch curr bulk collect into vvid,vvnm,vvtp limit 1000;  
        forall i in 1..vvid.count  
          insert into T_TEST2(TESTID,TESTNAME,TESTTYPE) values (vvid(i),vvnm(i),vvtp(i));  
          commit;  
        exit when curr%NOTFOUND;  
      end loop;  
      close curr;  
      -- 动态传入表名和参数  
      open curd;  
      loop  
        fetch curd bulk collect into vvid limit 1000;  
        forall i in 1..vvid.count  
          execute immediate ‘delete ‘||tabtest||‘ where TESTID=:tabid‘ using in vvid(i);  
          commit;  
        exit when curd%NOTFOUND;  
      end loop;  
      close curd;  
    end;  

bulk collect 和 forall 的联合应用
基本上压榨出了oracle中增删改的极限速度。
比用游标一条条处理要快太多了。