Oracle 的存储过程里面的SQL 语句（|| “！”）看不懂，望大家给个答案

Question

create or replace package body pck_imp_puryewu is

procedure searchList(
i_FLDPURCONTRACTNO in varchar2,
i_JK_DDH in varchar2,

i_FLDCREATEDATE in varchar2,
i_VERIFY in varchar2,
i_userId in varchar2,
o_retCode out varchar2,
o_tableHead out varchar2,
o_tablewidth out varchar2,
o_resultRef out REF_SEARCH

)
is
v_sql varchar2(3000);

begin
o_retCode := 0;

    v_sql := ' select FLDPURAGEID,FLDPURAGEID||''!''||JK_KHDDH||''!''||CONTRACTNO||''!''||Jk_Dntype||''!''||Fldcreatedate||''!''||FLDPURCHASER||''!''||';
    v_sql := v_sql || 'FLDAGENTNAME||''!''||FLDCURCODE||''!''||FLDCOMPANY||''!''||FLDAGENTDATE||''!''||';
    v_sql := v_sql || 'FLDIMPORTPORT||''!''||FLDBANKSTYLE||''!''||FLDCurrency||''!''||jk_rate';
    v_sql := v_sql || ' from TBLPURPLANINFO where  VERIFY=' || i_VERIFY;


    if length(i_FLDPURCONTRACTNO) > 0 then
       v_Sql := v_Sql || ' and FLDPURAGEID = ''' || i_FLDPURCONTRACTNO || '''';
    end if;

    if length( i_FLDCREATEDATE) > 0 then
       v_sql := v_Sql || ' and FLDCREATEDATE = ''' || i_FLDCREATEDATE || '''';
    end if;

    if length(i_JK_DDH) > 0 then
        v_sql := v_Sql || ' and JK_KHDDH = ''' || i_JK_DDH || '''';
    end if;

    if length(i_userId) > 0  then
       v_sql := v_Sql || ' and FLDPURCHASER = ''' || i_userId || '''';
    end if;



    o_tableHead := '委托书号#客户订单号#合同协议号#单据类型#录入日期#采购员#委托方名称#供应商名称#事业部名称#委托日期#进口口岸#付款方式#币制#汇率';
    o_tablewidth := '100#100#100#100#100#100#300#300#100#100#100#100#100#100';

    open o_resultRef for v_sql;

exception
WHEN OTHERS THEN
o_retCode := -1;
--操作异常
DBMS_OUTPUT.PUT_LINE(SQLERRM);
rollback;
end;

Answer 1

||的作用是拼接字符串
!的作用是分隔符

一般会用123,123,123来表示一条记录的3个字段的值，这里的都好起到了分隔符的作用。而写这个sql的人，没用逗号来做分隔符，而是用了叹号做分隔符，上面的那个例子就变成了123!123!123