String json =null; try{ json = mapper.writeValueAsString(attribute); }catch(JsonProcessingException e) { e.printStackTrace(); } returnjson; } @SuppressWarnings("unchecked") @Override publicList<String> convertToEntityAttribute(String dbData) { ObjectMapper mapper =newObjectMapper(); List<String>...
StringInfoData strinfo;/* we first convert char * to datum representation */jsonb_datum = DirectFunctionCall1(jsonb_in, CStringGetDatum(myjson));/* then, we convert it to Jsonb * */jb = DatumGetJsonbP(jsonb_datum);/* prepare element paths to fetch, from outer to inner */initStri...
class) private String json; ... } @Converter public class StringToJson implements AttributeConverter<String, JsonObject> { @Override public JsonObject convertToDatabaseColumn(String string) { if (string == null) { return null; } return new JsonObject(string); } @Override public String convert...
String>{@OverridepublicStringconvertToDatabaseColumn(List<String>attribute){if(attribute==null||attribute.size()==0)return"[]";ObjectMappermapper=newObjectMapper();Stringjson=null;try{json=mapper.writeValueAsString(attribute);}catch(JsonProcessingExceptione){e.printStackTrace();}returnjson;}@SuppressW...
void jsonb_example(const char * myjson) { Datum jsonb_datum; Jsonb * jb; /* variables needed for fetching element */ Datum datum_elems[2]; Datum res; int numpath = 2; bool isnull; StringInfoData strinfo; /* we first convert char * to datum representation */ ...
This page provides you with the most commonly used PostgreSQL JSON functions that allow you to manage JSON data effectively. Section 1. Creating JSON data This section covers the functions that help you create JSON data in SQL: to_jsonb() –Convert an SQL value to a value of JSONB. json...
在基于 C 语言的 PostgreSQL 扩展开发中,您可能会遇到需要处理 JSON 等结构化数据的情况。通常,您可能会在扩展中引入第三方 JSON 解析库,例如 cJSON 或 li...
/* myjson points to a complete JSON content */voidjsonb_example(constchar*myjson){Datum jsonb_datum;Jsonb*jb;/* variables needed for fetching element */Datum datum_elems[2];Datum res;intnumpath=2;bool isnull;StringInfoData strinfo;/* we first convert char * to datum representation *...
[Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes('<your string to encode here>'))#Example#[Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes('example')) Linux/macOS 控制台 echo -n '<your string to encode here>' | base64#Example#echo-n'example'| base64...
然而,PostgreSQL本身并没有内置的group_concat函数,但可以通过使用json_agg和string_agg函数来实现类似的功能。 概念:group_concat是一种将多行数据连接成一行的聚合函数,通常用于将多个值合并为一个字符串。 分类:group_concat属于聚合函数的一种,用于处理多行数据。 优势:使用group_concat可以方便地将多行数据合并为...