cursor B1 is select user_id, user_code, user_name, electric_power_ct, elec_number, zone_code from be_user t where t.zone_code = Chzonecode and t.user_type in ('0', '1', '8', '15'); B B1%rowtype;把这段sql中Chzonecode改成if判断不为空的时候才在where后面去匹配

你可以这样修改：

IF Chzonecode IS NOT NULL THEN
  OPEN B1 FOR
    SELECT user_id, user_code, user_name, electric_power_ct, elec_number, zone_code 
    FROM be_user t 
    WHERE t.zone_code = Chzonecode AND t.user_type IN ('0', '1', '8', '15');
ELSE
  OPEN B1 FOR
    SELECT user_id, user_code, user_name, electric_power_ct, elec_number, zone_code 
    FROM be_user t 
    WHERE t.user_type IN ('0', '1', '8', '15');
END IF;

FETCH B1 INTO B;
WHILE B1%FOUND LOOP
  -- do something with B
  FETCH B1 INTO B;
END LOOP;

CLOSE B1;

这样修改后，如果Chzonecode为空，就会执行第二个SELECT语句，否则就执行第一个SELECT语句。

相关问题

解释一下这段sql：cursor B1 is select user_id, user_code, user_name, electric_power_ct, elec_number, zone_code from be_user t where t.zone_code = Chzonecode and t.user_type in ('0', '1', '8', '15'); B B1%rowtype;

这段SQL是PL/SQL语言中用于定义游标的代码。具体解释如下：

- `cursor B1 is`：定义游标名称为B1。
- `select user_id, user_code, user_name, electric_power_ct, elec_number, zone_code from be_user t where t.zone_code = Chzonecode and t.user_type in ('0', '1', '8', '15');`：查询语句，查询表be_user中的user_id、user_code、user_name、electric_power_ct、elec_number和zone_code字段，其中筛选条件是zone_code等于变量Chzonecode的值，并且user_type字段的值为0、1、8或15。
- `B B1%rowtype;`：定义一个记录类型为B1游标返回结果的记录变量B。

综上，这段SQL的作用是定义了一个名为B1的游标，用于查询be_user表中符合条件的记录，并将结果赋值给记录变量B。

IF Chzonecode IS NOT NULL THEN OPEN B1 FOR SELECT user_id, user_code, user_name, electric_power_ct, elec_number, zone_code FROM be_user t WHERE t.zone_code = Chzonecode AND t.user_type IN ('0', '1', '8', '15');ELSE OPEN B1 FOR SELECT user_id, user_code, user_name, electric_power_ct, elec_number, zone_code FROM be_user t WHERE t.user_type IN ('0', '1', '8', '15');END IF;FETCH B1 INTO B;WHILE B1%FOUND LOOP -- do something with B FETCH B1 INTO B;END LOOP;CLOSE B1; 这样会报错请声明B1，请重新修改一下

好的，修改如下：

DECLARE
B1 SYS_REFCURSOR;
B be_user%ROWTYPE;
BEGIN
IF Chzonecode IS NOT NULL THEN
OPEN B1 FOR
SELECT user_id, user_code, user_name, electric_power_ct, elec_number, zone_code
FROM be_user t
WHERE t.zone_code = Chzonecode AND t.user_type IN ('0', '1', '8', '15');
ELSE
OPEN B1 FOR
SELECT user_id, user_code, user_name, electric_power_ct, elec_number, zone_code
FROM be_user t
WHERE t.user_type IN ('0', '1', '8', '15');
END IF;

FETCH B1 INTO B;
WHILE B1%FOUND LOOP
-- do something with B
FETCH B1 INTO B;
END LOOP;

CLOSE B1;
END;