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Select renamed to Query and rewritten

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Now it uses pgx.CollectRows build-in method
This commit is contained in:
Dmitry Anderson 2024-11-12 14:36:20 +01:00
parent 179310ac85
commit ce71a3a553
3 changed files with 13 additions and 44 deletions
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1
go.mod
View File

@ -9,6 +9,7 @@ require (
github.com/jackc/pgpassfile v1.0.0 // indirect
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
github.com/jackc/pgx/v5 v5.7.1 // indirect
github.com/matchsystems/werr v0.1.3 // indirect
go.uber.org/atomic v1.7.0 // indirect
golang.org/x/crypto v0.27.0 // indirect
golang.org/x/text v0.18.0 // indirect

2
go.sum
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@ -13,6 +13,8 @@ github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7Ulw
github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
github.com/jackc/pgx/v5 v5.7.1 h1:x7SYsPBYDkHDksogeSmZZ5xzThcTgRz++I5E+ePFUcs=
github.com/jackc/pgx/v5 v5.7.1/go.mod h1:e7O26IywZZ+naJtWWos6i6fvWK+29etgITqrqHLfoZA=
github.com/matchsystems/werr v0.1.3 h1:h932fzdGLE67w5O8F3O2vO49KkjmSeqsFQqDFkIOMYM=
github.com/matchsystems/werr v0.1.3/go.mod h1:MpZemBWOQ0IuQogwr5aCjNnIfWe+iEfnSh7nTGQ3M7I=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=

54
pg/pg.go
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@ -2,25 +2,18 @@ package pgUtils
import (
"context"
"errors"
reflectUtils "git.mic.pp.ua/anderson/nettools/reflect"
"github.com/jackc/pgx/v5"
"github.com/jackc/pgx/v5/pgxpool"
)
var (
ErrEntityNotFound = errors.New("entity not found")
ErrTooManyRows = errors.New("too many rows")
ErrEntityAlreadyExists = errors.New("entity already exists")
ErrNoDstFields = errors.New("no destination fields")
"github.com/matchsystems/werr"
)
type PgxQuerier interface {
Query(ctx context.Context, sql string, args ...any) (pgx.Rows, error)
QueryRow(ctx context.Context, sql string, args ...any) (pgx.Row, error)
}
// Select executes query on a provided querier and tries to parse db response
// Works only with objects
// Query executes query on a provided querier and tries to parse db response
// Works only with structs
//
// Usage:
//
@ -30,44 +23,17 @@ type PgxQuerier interface {
// }
//
// db := pgx.Connect(context.Background(), "<url>")
// users, err := pgUtils.Select[User](context.Background(), db, "SELECT id, name FROM users")
func Select[T any](ctx context.Context, db PgxQuerier, query string, args ...any) (out []*T, err error) {
// users, err := pgUtils.Query[User](context.Background(), db, "SELECT id, name FROM users")
func Query[T any](ctx context.Context, db PgxQuerier, query string, args ...any) (out []T, err error) {
rows, err := db.Query(ctx, query, args)
if err != nil {
switch {
case errors.Is(err, pgx.ErrNoRows):
err = ErrEntityNotFound
} // TODO: extend cases
return nil, err
}
// Get column names
columns := make([]string, len(rows.FieldDescriptions()))
for i, fd := range rows.FieldDescriptions() {
columns[i] = fd.Name
entities, err := pgx.CollectRows(rows, pgx.RowToStructByNameLax[T])
if err != nil {
return nil, werr.Wrapf(err, "failed to parse query results")
}
itemFieldPtrs := make([]any, len(columns))
out = []*T{}
defer rows.Close()
for rows.Next() {
item := new(T)
dstItemPtrsMap, err := reflectUtils.GetEntityPtrs(item, "db")
if err != nil {
return nil, err
}
for i, columnName := range columns {
itemFieldPtrs[i] = dstItemPtrsMap[columnName]
}
if len(itemFieldPtrs) == 0 {
return nil, ErrNoDstFields
}
if err = rows.Scan(itemFieldPtrs...); err != nil {
return out, err
}
out = append(out, item)
}
return out, err
return entities, nil
}
// Tx creates new transaction. Cancels it if returned not nil err