[英][dotnet core MVC], I can't get file from byte array (field stored into database).
[英]How can i get JSON ARRAY value from POSTGRESQL(npgsql) table in dotnet core 5
我正在使用带有 PostgreSQL 的 dotnet core 5 我想从 json 数组中获取数据以列出。 如何实现它,我尝试了一些在网上发现的方法,不幸的是没有任何效果
请看看我的代码和表格
我的桌子
CREATE TABLE settings.tbl_settings (
pk_settings_id BIGSERIAL PRIMARY KEY,
vhr_settings_sys_name VARCHAR(250) NOT NULL,
vhr_label VARCHAR(250) NOT NULL,
vhr_value VARCHAR(500) NOT NULL,
arj_select_items JSON ARRAY,
txt_remarks TEXT DEFAULT ''
);
我尝试在 C#
foreach (DataRow objRecord in objDataSet.Tables[0].Rows)
{
mdlSettings.lstSelectItems = JObject.Parse(objRecord["arj_select_items"].ToString());
or
mdlSettings.lstSelectItems = (DBNull.Value != objRecord["arj_select_items"]) ? JsonSerializer.Deserialize<List<MdlSettingsValueOptions>>(objRecord["arj_select_items"].ToString()) : mdlSettings.lstSelectItems;
or
mdlSettings.lstSelectItems = (DBNull.Value != objRecord["arj_select_items"]) ? JsonConvert.DeserializeObject<List<MdlSettingsValueOptions>>(objRecord["arj_select_items"].ToString()) : mdlSettings.lstSelectItems;
}
错误
Unexpected character encountered while parsing value: S. Path '', line 0, position 0.
我收到这些错误
我也试过这些
var a = objRecord["arj_select_items"].ToString();
得到这些错误
System.String[]
objRecord["arj_select_items"] 不是 json,它是一个字符串数组。 因此,您应该反序列化数组的每个元素:
foreach (DataRow objRecord in objDataSet.Tables[0].Rows)
{
mdlSettings.lstSelectItems = ((string[])objRecord["arj_select_items"])
.Select(item => JsonSerializer.Deserialize<MdlSettingsValueOptions>(item));
}
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