package sq import ( "context" "fmt" "gogs.mikescher.com/BlackForestBytes/goext/exerr" "gogs.mikescher.com/BlackForestBytes/goext/langext" pag "gogs.mikescher.com/BlackForestBytes/goext/pagination" ) func Paginate[TData any](ctx context.Context, q Queryable, table string, filter PaginateFilter, scanMode StructScanMode, scanSec StructScanSafety, page int, limit *int) ([]TData, pag.Pagination, error) { prepParams := PP{} sortOrder := filter.Sort() sortCond := "" if len(sortOrder) > 0 { sortCond = "ORDER BY " for i, v := range sortOrder { if i > 0 { sortCond += ", " } sortCond += v.Field + " " + string(v.Direction) } } pageCond := "" if limit != nil { pageCond += fmt.Sprintf("LIMIT :%s OFFSET :%s", prepParams.Add(*limit+1), prepParams.Add(*limit*(page-1))) } filterCond, joinCond, joinTables := filter.SQL(prepParams) selectCond := table + ".*" for _, v := range joinTables { selectCond += ", " + v + ".*" } sqlQueryData := "SELECT " + selectCond + " FROM " + table + " " + joinCond + " WHERE ( " + filterCond + " ) " + sortCond + " " + pageCond sqlQueryCount := "SELECT " + "COUNT(*)" + " FROM " + table + " " + joinCond + " WHERE ( " + filterCond + " ) " rows, err := q.Query(ctx, sqlQueryData, prepParams) if err != nil { return nil, pag.Pagination{}, exerr.Wrap(err, "failed to list paginated entries from DB").Str("table", table).Any("filter", filter).Int("page", page).Any("limit", limit).Build() } entities, err := ScanAll[TData](ctx, q, rows, scanMode, scanSec, true) if err != nil { return nil, pag.Pagination{}, exerr.Wrap(err, "failed to decode paginated entries from DB").Str("table", table).Int("page", page).Any("limit", limit).Str("scanMode", string(scanMode)).Str("scanSec", string(scanSec)).Build() } if page == 1 && (limit == nil || len(entities) <= *limit) { return entities, pag.Pagination{ Page: 1, Limit: langext.Coalesce(limit, len(entities)), TotalPages: 1, TotalItems: len(entities), CurrentPageCount: 1, }, nil } else { countRows, err := q.Query(ctx, sqlQueryCount, prepParams) if err != nil { return nil, pag.Pagination{}, exerr.Wrap(err, "failed to query total-count of paginated entries from DB").Str("table", table).Build() } if !countRows.Next() { return nil, pag.Pagination{}, exerr.New(exerr.TypeSQLDecode, "SQL COUNT(*) query returned no rows").Str("table", table).Any("filter", filter).Build() } var countRes int err = countRows.Scan(&countRes) if err != nil { return nil, pag.Pagination{}, exerr.Wrap(err, "failed to decode total-count of paginated entries from DB").Str("table", table).Build() } if len(entities) > *limit { entities = entities[:*limit] } paginationObj := pag.Pagination{ Page: page, Limit: langext.Coalesce(limit, countRes), TotalPages: pag.CalcPaginationTotalPages(countRes, langext.Coalesce(limit, countRes)), TotalItems: countRes, CurrentPageCount: len(entities), } return entities, paginationObj, nil } } func Count(ctx context.Context, q Queryable, table string, filter PaginateFilter) (int, error) { prepParams := PP{} filterCond, joinCond, _ := filter.SQL(prepParams) sqlQueryCount := "SELECT " + "COUNT(*)" + " FROM " + table + " " + joinCond + " WHERE ( " + filterCond + " )" countRows, err := q.Query(ctx, sqlQueryCount, prepParams) if err != nil { return 0, exerr.Wrap(err, "failed to query count of entries from DB").Str("table", table).Build() } if !countRows.Next() { return 0, exerr.New(exerr.TypeSQLDecode, "SQL COUNT(*) query returned no rows").Str("table", table).Any("filter", filter).Build() } var countRes int err = countRows.Scan(&countRes) if err != nil { return 0, exerr.Wrap(err, "failed to decode count of entries from DB").Str("table", table).Build() } return countRes, nil }