end
c45e8abe08
Add transport-neutral keyset pagination through native Bob query mods. Preserve supported cursor value types in a compact versioned format, with bidirectional pages, explicit row keys, and a separate opt-in count. Include SQLite tests, PostgreSQL service CI, and the cursor-format ADR. Closes #6
70 lines
2.3 KiB
Go
70 lines
2.3 KiB
Go
package page_test
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import (
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"context"
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"errors"
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"fmt"
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"github.com/stephenafamo/bob"
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"github.com/stephenafamo/bob/dialect/sqlite"
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sd "github.com/stephenafamo/bob/dialect/sqlite/dialect"
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"github.com/stephenafamo/bob/dialect/sqlite/sm"
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"github.com/stephenafamo/bob/expr"
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"github.com/stephenafamo/scan"
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"go.auvem.com/corestack/page"
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)
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func Example() {
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ctx := context.Background()
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db, err := bob.Open("sqlite3", ":memory:")
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if err != nil {
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panic(err)
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}
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defer db.Close()
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db.SetMaxOpenConns(1)
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if _, err := db.ExecContext(ctx, "CREATE TABLE orders (id BIGINT PRIMARY KEY, priority BIGINT NOT NULL, tenant BIGINT NOT NULL)"); err != nil {
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panic(err)
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}
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if _, err := db.ExecContext(ctx, "INSERT INTO orders VALUES (1,10,7),(2,10,7),(3,5,7),(4,20,8)"); err != nil {
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panic(err)
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}
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type Order struct {
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ID int64
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Priority int64
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}
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sort := page.Sort{ID: "orders/priority/v1", Columns: []page.Column{
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{Expression: expr.Quote("priority"), Direction: page.Desc},
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{Expression: expr.Quote("id"), Direction: page.Asc, Unique: true},
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}}
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// With Bob-generated models, use their column references for these expressions.
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// The key must independently match their order and actual stored value types.
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key := func(o Order) []any { return []any{o.Priority, o.ID} }
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p, err := page.Prepare(sort, key, page.Request{Size: 2}, page.Limits{Default: 2, Maximum: 100})
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if err != nil {
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panic(err)
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}
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q := sqlite.Select(sm.Columns("id", "priority"), sm.From("orders"), page.Mod[*sd.SelectQuery](p))
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q.Apply(sm.Where(sqlite.Quote("tenant").EQ(sqlite.Arg(int64(7)))))
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rows, err := bob.All(ctx, db, q, scan.StructMapper[Order]())
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if err != nil {
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panic(err)
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}
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result, err := p.Page(rows)
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if err != nil {
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panic(err)
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}
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fmt.Println(result.Items, result.HasNext, result.HasPrevious)
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// Continue with Forward + result.EndCursor, or Backward + result.StartCursor.
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// A mismatched key returns no partial Page, including for an overflow row.
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bad, err := page.Prepare(sort, func(o Order) []any { return []any{o.ID} }, page.Request{}, page.Limits{Default: 2, Maximum: 100})
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if err != nil {
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panic(err)
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}
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_, err = bad.Page(rows)
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var keyError *page.KeyError
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fmt.Println(errors.As(err, &keyError), keyError.Expected, keyError.Actual)
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// Output:
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// [{1 10} {2 10}] true false
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// true 2 1
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}
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