{"draftJsState":{"blocks":[{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Задача: проверить наличие записи по строке","type":"header-two","key":"f9u3a"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Не оптимальные пути","type":"header-three","key":"6shmq"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"DataStore.GetAll().Any(x => x.Code == \"123\");","type":"blockquote","key":"hj2h"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Генерируемый SQL: select * from foo where code=$1 limit 1","type":"unstyled","key":"flktl"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Проблемы этого решения:","type":"unstyled","key":"d8gs6"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"расходы на получение всей записи с маппингом в объект памяти","type":"unordered-list-item","key":"6u5i0"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"регистрозависимый поиск по полю code (обычно это не нужно)","type":"unordered-list-item","key":"moqr"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"DataStore.GetAll().Any(x => x.Code.ToLower() == \"123\");","type":"blockquote","key":"8vmof"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Генерируемый SQL: select * from foo where lower(code)=$1 limit 1","type":"unstyled","key":"dgh9u"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Проблемы этого решения:","type":"unstyled","key":"4j4am"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"расходы на получение всей записи с маппингом в объект памяти","type":"unordered-list-item","key":"173ip"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Оптимальные пути","type":"header-three","key":"3cicg"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"DataStore.GetAll().Select(x => x.Code).AnyAsync(x => SqlMethods.Like(x.ToLower(), \"123\"));","type":"blockquote","key":"46dne"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"select code from foo where lower(code) like $1 limit 1","type":"unstyled","key":"ll7g"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"","type":"unstyled","key":"2gc8g"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"DataStore.GetAll().Count(x => SqlMethods.Like(x.Code.ToLower(), \"123\")) > 0;","type":"blockquote","key":"dgiul"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"select count(*) from foo where lower(code) like $1","type":"unstyled","key":"bfr64"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":58,"offset":0,"style":"ITALIC"}],"text":"Выборка count(*) плохо себя показывает на больших таблицах","type":"unstyled","key":"22kuk"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"","type":"unstyled","key":"92jk"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"DataStore.GetAll().Count(x => x.Code.Equals(\"123\", StringComparison.OrdinalIgnoreCase)) > 0;","type":"blockquote","key":"1btas"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"select count(*) from foo where lower(code)=lower($1)","type":"unstyled","key":"4nr0t"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":58,"offset":0,"style":"ITALIC"}],"text":"Выборка count(*) плохо себя показывает на больших таблицах","type":"unstyled","key":"12lig"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"","type":"unstyled","key":"97p1e"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"DataStore.GetAll().Count(x => x.Code.ToLower() == \"123\") > 0;","type":"blockquote","key":"boqid"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"select count(*) from foo where lower(code)=$1","type":"unstyled","key":"3lsrb"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":58,"offset":0,"style":"ITALIC"}],"text":"Выборка count(*) плохо себя показывает на больших таблицах","type":"unstyled","key":"9gt4s"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"","type":"unstyled","key":"ctaf5"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":50,"offset":41,"style":"ITALIC"}],"text":"DataStore.GetAll().Where(x => x.Code.Equals(\"123\", StringComparison.OrdinalIgnoreCase)).Select(x => 1).FirstOrDefaultAsync() == 1;","type":"blockquote","key":"6p1r0"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"select 1 from foo where lower(code)=lower($1)","type":"unstyled","key":"336k0"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Лучше себя показывает на больших таблицах (если запись не в конце таблицы), хорошо чувствует себя при наличии индекса по Code","type":"unstyled","key":"4r71h"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Для удобства:","type":"unstyled","key":"fuojc"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"public static async Task ExistsAsync(this IQueryable source, Expression> predicate, CancellationToken cancellationToken = default)","type":"blockquote","key":"cogu6"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":5,"offset":22,"style":"ITALIC"},{"length":36,"offset":38,"style":"ITALIC"}],"text":"{ return await source.Where(predicate).Select(x => 1).FirstOrDefaultAsync(cancellationToken) == 1; }","type":"blockquote","key":"b31fh"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"","type":"marker","key":"clD0xaocU5yeO70D3vBJ"}],"entityMap":{}},"mentions":[]}