如何在嵌套数组中使用 apex_json.get_count
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【中文标题】如何在嵌套数组中使用 apex_json.get_count【英文标题】：How to use apex_json.get_count in a nested array 【发布时间】：2021-04-15 18:09:32 【问题描述】：我正在尝试从我的 json 中的好处元素的计数中循环遍历数组。尽管 apex json 中的 get count 函数返回一个数字，但我不断收到数值错误。
如果我们将循环更改为 for 1 in 1..2 - 它可以正常工作。
如果我们将数组索引硬编码为 1，则代码有效，但如果我们尝试使用 %d p0 传递变量，则会出现数值错误 - ORA - 06502。
下面是代码：
j apex_json.t_values;
l_count_chg number;
l_count_pers number;
l_count_ben number;
l_members wwv_flow_t_varchar2;
l_paths apex_t_varchar2;
l_paths2 apex_t_varchar2;
l_paths3 apex_t_varchar2;
v_get_person varchar2(10);
v_get_benefit varchar2(10);
v_get_benopt varchar2(10);
r_count number;
begin
apex_json.parse(j,'
"PolicyUpdate":
"contractNumber": 12345,
"effectiveDate": "2022-04-01",
"planChanges": [
"changeCode": 1,
"roleplayerId": "pers1",
"person":
"id": "pers1",
"surname": "Hazy",
"firstName": "Smith",
"benefits": [
"Id": "ben1",
"typeCode": "C1",
"benefitName": "Funeral Benefit",
"roleplayerId": "pers1",
"coverAmount": 10000,
"premiumAmount": 47.47,
"StartDate": "2021-04-01",
"Options":
"Option": [
"Label": "Risk Benefit Classification",
"Value": "Main Life"
,
"Label": "Waiting Period (DOC to Event)",
"Value": "6 Months"
,
"Label": "Paid Up Benefit (Y/N)",
"Value": "No"
]
,
"Id": "ben2",
"typeCode": "C1",
"benefitName": "Tombstone Benefit",
"roleplayerId": "pers1",
"coverAmount": 5000,
"premiumAmount": 10.47,
"StartDate": "2021-04-01"
]
,
"changeCode": 2,
"roleplayerId": "pers2"
]
');
dbms_output.put_line('Contract Number : ' ||
apex_json.get_varchar2(p_path => 'PolicyUpdate.contractNumber'));
dbms_output.put_line('Effective Adte : ' ||
apex_json.get_varchar2(p_path => 'PolicyUpdate.effectiveDate'));
dbms_output.put_line('----------------------------------------');
l_count_chg := apex_json.get_count(p_path => 'PolicyUpdate.planChanges',p_values=>j);
dbms_output.put_line('change count '||l_count_chg);
for i in 1..l_count_chg loop
dbms_output.put_line('changeCode '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].changeCode' ,p_values=>j,p0 => i));
dbms_output.put_line('roleplayerId '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].roleplayerId',p_values=>j,p0 => i));
dbms_output.put_line('firstname '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].person.firstName',p_values=>j,p0 => i));
l_count_ben := apex_json.get_count(p_path => 'PolicyUpdate.planChanges[%d].person.benefits',p_values=>j);
dbms_output.put_line('benefit count '|| l_count_ben);
for x in 1..l_count_ben loop
dbms_output.put_line('ben id '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].person.benefits[%d].Id',p_values=>j,p0 => i,p1 => x));
end loop;
end loop;
end;
【问题讨论】：
【参考方案1】：对我来说，计数没有返回数字（只是没有值），所以我做了一些更改 - 我发现在获取计数之前检查路径是否存在是最安全的：
declare
j apex_json.t_values;
l_count_chg number;
l_count_pers number;
l_count_ben number;
l_members wwv_flow_t_varchar2;
l_paths apex_t_varchar2;
l_paths2 apex_t_varchar2;
l_paths3 apex_t_varchar2;
v_get_person varchar2(10);
v_get_benefit varchar2(10);
v_get_benopt varchar2(10);
r_count number;
begin
apex_json.parse(j,'
"PolicyUpdate":
"contractNumber": 12345,
"effectiveDate": "2022-04-01",
"planChanges": [
"changeCode": 1,
"roleplayerId": "pers1",
"person":
"id": "pers1",
"surname": "Hazy",
"firstName": "Smith",
"benefits": [
"Id": "ben1",
"typeCode": "C1",
"benefitName": "Funeral Benefit",
"roleplayerId": "pers1",
"coverAmount": 10000,
"premiumAmount": 47.47,
"StartDate": "2021-04-01",
"Options":
"Option": [
"Label": "Risk Benefit Classification",
"Value": "Main Life"
,
"Label": "Waiting Period (DOC to Event)",
"Value": "6 Months"
,
"Label": "Paid Up Benefit (Y/N)",
"Value": "No"
]
,
"Id": "ben2",
"typeCode": "C1",
"benefitName": "Tombstone Benefit",
"roleplayerId": "pers1",
"coverAmount": 5000,
"premiumAmount": 10.47,
"StartDate": "2021-04-01"
]
,
"changeCode": 2,
"roleplayerId": "pers2"
]
');
dbms_output.put_line('Contract Number : ' ||
apex_json.get_varchar2(p_path => 'PolicyUpdate.contractNumber',p_values => j));
dbms_output.put_line('Effective Adte : ' ||
apex_json.get_varchar2(p_path => 'PolicyUpdate.effectiveDate',p_values => j));
dbms_output.put_line('----------------------------------------');
l_count_chg := apex_json.get_count(p_path => 'PolicyUpdate.planChanges',p_values=>j);
dbms_output.put_line('change count '||l_count_chg);
for i in 1..l_count_chg loop
dbms_output.put_line('changeCode '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].changeCode' ,p_values=>j,p0 => i));
dbms_output.put_line('roleplayerId '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].roleplayerId',p_values=>j,p0 => i));
dbms_output.put_line('firstname '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].person.firstName',p_values=>j,p0 => i));
IF apex_json.does_exist(p_path => 'PolicyUpdate.planChanges[%d].person.benefits',p0 => i,p_values=>j) THEN
l_count_ben := apex_json.get_count(p_path => 'PolicyUpdate.planChanges[%d].person.benefits',p0 => i,p_values=>j);
dbms_output.put_line('benefit count '|| l_count_ben);
for x in 1..l_count_ben loop
dbms_output.put_line('ben id '||apex_json.get_varchar2(p_path => 'PolicyUpdate.planChanges[%d].person.benefits[%d].Id',p_values=>j,p0 => i,p1 => x));
end loop;
END IF;
end loop;
end;
【讨论】：
【参考方案2】：Koen 建议使用 EXISTS 进行测试非常好。
他也添加了这个，但没有说明您的原始版本似乎缺少参数：
p0 => i
在计算l_count_ben时
所以 get_count 的值是未知的。
【讨论】：
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