PLSQL入门：cursor传参，loop fetch使用，if使用，单引号字符表示

1、cursor传入参数

定义：cursor [cursor变量名称]([参数名称] [参数类型]) IS [SQL语句，可以使用传入参数]

例子：
cursor moTypeNames(domain VARCHAR2) IS
select t1.modelname from pm4h_mo.mdl_resmodel t1,pm4h_mo.mdl_domain t2
where t2.domainname=domain
and t1.domainid = t2.domainid;
使用：open [cursor变量名称]([参数])

例子：

open moTypeNames(domainName);

2、loop fetch使用

fetch [cursor变量] into [循环变量]

when [cursor变量] %notfound;

例子：

loop

fetch domainNames into domainName;
exit when domainNames%notfound;

end loop;

3、if使用

if(条件) then

[真值语句块]

end if;

4、单引号字符表示

''''：最外层两个单引号表示字符串引用，字符串中间第一个单引号表示转义，第二个单引号表示单引号。

例子：

v_sql :='select count(*)
from pm4h_mo.mdl_resmodel t1, pm4h_mo.mdl_resmodeltable t2
where t1.modelname='''||moTypeName||''' and t1.modelid=t2.modelid';

5、open cursor后要注意close cursor

declare
--存储域名
type t_cur is ref cursor;
domainNames     t_cur;
domainName      varchar2(50) :='';

--存储每个域下的网元类型
cursor moTypeNames(domain VARCHAR2) IS
select t1.modelname from pm4h_mo.mdl_resmodel t1,pm4h_mo.mdl_domain t2
where t2.domainname=domain
and t1.domainid = t2.domainid;
moTypeName      varchar2(500) :='';

--拼接sql临时变量
v_sql           varchar2(500) :='';

--网元实体表名称
tableName       varchar2(500) :='';

--每个网元类型实体数
v_count_number  number(30) :=0;

--总实体数
v_count_sum     number(30) :=0;
begin
--不限制输出长度
dbms_output.enable(null);

--查询域名
open domainNames for
select domainname from pm4h_mo.mdl_domain;

--循环域名
loop
fetch domainNames into domainName;
exit when domainNames%notfound;
dbms_output.put_line(domainName);

--查询MoType
open moTypeNames(domainName);

--循环MoType
loop
fetch moTypeNames into moTypeName;
exit when moTypeNames%notfound;
dbms_output.put(moTypeName);

--查询是否存在实体表：ElementMoType不存在实体表
v_sql :='select count(*)
from pm4h_mo.mdl_resmodel t1, pm4h_mo.mdl_resmodeltable t2
where  t1.modelname='''||moTypeName||''' and  t1.modelid=t2.modelid';
execute immediate v_sql
into v_count_number;

if(v_count_number <> 0) then
--存在实体表，查询实体表名
v_sql :='select t2.tablename
from pm4h_mo.mdl_resmodel t1, pm4h_mo.mdl_resmodeltable t2
where  t1.modelname='''||moTypeName||''' and t1.modelid=t2.modelid';
execute immediate v_sql
into tableName;

--查询实体数量
v_sql := 'select count(*) from pm4h_mo.obj_'||tableName || '  where verendtime is null';
execute immediate v_sql
into v_count_number;
dbms_output.put_line(':'||v_count_number);

--计算实体总量
v_count_sum :=v_count_sum+v_count_number;
end if;
end loop;
dbms_output.put_line('');
close moTypeNames;
end loop;
dbms_output.put_line('total:'||v_count_sum);
close domainNames;
end;