feat(mysql): support ORDER BY and LIMIT clauses in UPDATE and DELETE …

…statements

dialect/feature/feature.go

@@ -31,5 +31,7 @@ const (
 	UpdateFromTable
 	MSSavepoint
 	GeneratedIdentity
-	CompositeIn // ... WHERE (A,B) IN ((N, NN), (N, NN)...)
+	CompositeIn      // ... WHERE (A,B) IN ((N, NN), (N, NN)...)
+	UpdateOrderLimit // UPDATE ... ORDER BY ... LIMIT ...
+	DeleteOrderLimit // DELETE ... ORDER BY ... LIMIT ...
 )

dialect/mysqldialect/dialect.go

@@ -49,7 +49,9 @@ func New(opts ...DialectOption) *Dialect {
 		feature.InsertIgnore |
 		feature.InsertOnDuplicateKey |
 		feature.SelectExists |
-		feature.CompositeIn
+		feature.CompositeIn |
+		feature.UpdateOrderLimit |
+		feature.DeleteOrderLimit
 
 	for _, opt := range opts {
 		opt(d)

internal/dbtest/query_test.go

@@ -1556,6 +1556,35 @@ func TestQuery(t *testing.T) {
 				return db.NewInsert().Model(new(Model))
 			},
 		},
+		{
+			id: 168,
+			query: func(db *bun.DB) schema.QueryAppender {
+				// DELETE ... ORDER BY ... (MySQL, MariaDB)
+				return db.NewDelete().Model(new(Model)).WherePK().Order("id")
+			},
+		},
+		{
+			id: 169,
+			query: func(db *bun.DB) schema.QueryAppender {
+				// DELETE ... ORDER BY ... LIMIT ... (MySQL, MariaDB)
+				return db.NewDelete().Model(new(Model)).WherePK().Order("id").Limit(1)
+			},
+		},
+		{
+			id: 170,
+			query: func(db *bun.DB) schema.QueryAppender {
+				// DELETE ... USING ... ORDER BY ... LIMIT ... (MySQL, MariaDB)
+				return db.NewDelete().Model(new(Story)).TableExpr("archived_stories AS src").
+					Where("src.id = story.id").Order("src.id").Limit(1)
+			},
+		},
+		{
+			id: 171,
+			query: func(db *bun.DB) schema.QueryAppender {
+				// UPDATE ... SET ... ORDER BY ... LIMIT ... (MySQL, MariaDB)
+				return db.NewUpdate().Model(new(Story)).Set("name = ?", "new-name").WherePK().Order("id").Limit(1)
+			},
+		},
 	}
 
 	timeRE := regexp.MustCompile(`'2\d{3}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}(\.\d+)?(\+\d{2}:\d{2})?'`)

internal/dbtest/testdata/snapshots/TestQuery-mariadb-168

@@ -0,0 +1 @@
+DELETE FROM `models` WHERE (`id` = NULL) ORDER BY `id`

internal/dbtest/testdata/snapshots/TestQuery-mariadb-169

@@ -0,0 +1 @@
+DELETE FROM `models` WHERE (`id` = NULL) ORDER BY `id` LIMIT 1

internal/dbtest/testdata/snapshots/TestQuery-mariadb-170

@@ -0,0 +1 @@
+bun: can't use ORDER or LIMIT with multiple tables

internal/dbtest/testdata/snapshots/TestQuery-mariadb-171

@@ -0,0 +1 @@
+UPDATE `stories` AS `story` SET name = 'new-name' WHERE (`story`.`id` = NULL) ORDER BY `id` LIMIT 1

internal/dbtest/testdata/snapshots/TestQuery-mssql2019-168

@@ -0,0 +1 @@
+bun: order is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-mssql2019-169

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-mssql2019-170

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-mssql2019-171

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-mysql5-168

@@ -0,0 +1 @@
+DELETE FROM `models` WHERE (`id` = NULL) ORDER BY `id`

internal/dbtest/testdata/snapshots/TestQuery-mysql5-169

@@ -0,0 +1 @@
+DELETE FROM `models` WHERE (`id` = NULL) ORDER BY `id` LIMIT 1

internal/dbtest/testdata/snapshots/TestQuery-mysql5-170

@@ -0,0 +1 @@
+bun: can't use ORDER or LIMIT with multiple tables

internal/dbtest/testdata/snapshots/TestQuery-mysql5-171

@@ -0,0 +1 @@
+UPDATE `stories` AS `story` SET name = 'new-name' WHERE (`story`.`id` = NULL) ORDER BY `id` LIMIT 1

internal/dbtest/testdata/snapshots/TestQuery-mysql8-168

@@ -0,0 +1 @@
+DELETE FROM `models` AS `model` WHERE (`model`.`id` = NULL) ORDER BY `id`

internal/dbtest/testdata/snapshots/TestQuery-mysql8-169

@@ -0,0 +1 @@
+DELETE FROM `models` AS `model` WHERE (`model`.`id` = NULL) ORDER BY `id` LIMIT 1

internal/dbtest/testdata/snapshots/TestQuery-mysql8-170

@@ -0,0 +1 @@
+bun: can't use ORDER or LIMIT with multiple tables

internal/dbtest/testdata/snapshots/TestQuery-mysql8-171

@@ -0,0 +1 @@
+UPDATE `stories` AS `story` SET name = 'new-name' WHERE (`story`.`id` = NULL) ORDER BY `id` LIMIT 1

internal/dbtest/testdata/snapshots/TestQuery-pg-168

@@ -0,0 +1 @@
+bun: order is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pg-169

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pg-170

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pg-171

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pgx-168

@@ -0,0 +1 @@
+bun: order is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pgx-169

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pgx-170

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-pgx-171

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-sqlite-168

@@ -0,0 +1 @@
+bun: order is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-sqlite-169

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-sqlite-170

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

internal/dbtest/testdata/snapshots/TestQuery-sqlite-171

@@ -0,0 +1 @@
+bun: limit is not supported for current dialect

query_base.go

@@ -6,6 +6,8 @@ import (
 	"database/sql/driver"
 	"errors"
 	"fmt"
+	"strconv"
+	"strings"
 	"time"
 
 	"github.com/uptrace/bun/dialect"
@@ -1352,3 +1354,113 @@ func (ih *idxHintsQuery) bufIndexHint(
 	b = append(b, ")"...)
 	return b, nil
 }
+
+//------------------------------------------------------------------------------
+
+type orderLimitOffsetQuery struct {
+	order []schema.QueryWithArgs
+
+	limit  int32
+	offset int32
+}
+
+func (q *orderLimitOffsetQuery) addOrder(orders ...string) {
+	for _, order := range orders {
+		if order == "" {
+			continue
+		}
+
+		index := strings.IndexByte(order, ' ')
+		if index == -1 {
+			q.order = append(q.order, schema.UnsafeIdent(order))
+			continue
+		}
+
+		field := order[:index]
+		sort := order[index+1:]
+
+		switch strings.ToUpper(sort) {
+		case "ASC", "DESC", "ASC NULLS FIRST", "DESC NULLS FIRST",
+			"ASC NULLS LAST", "DESC NULLS LAST":
+			q.order = append(q.order, schema.SafeQuery("? ?", []interface{}{
+				Ident(field),
+				Safe(sort),
+			}))
+		default:
+			q.order = append(q.order, schema.UnsafeIdent(order))
+		}
+	}
+
+}
+
+func (q *orderLimitOffsetQuery) addOrderExpr(query string, args ...interface{}) {
+	q.order = append(q.order, schema.SafeQuery(query, args))
+}
+
+func (q *orderLimitOffsetQuery) appendOrder(fmter schema.Formatter, b []byte) (_ []byte, err error) {
+	if len(q.order) > 0 {
+		b = append(b, " ORDER BY "...)
+
+		for i, f := range q.order {
+			if i > 0 {
+				b = append(b, ", "...)
+			}
+			b, err = f.AppendQuery(fmter, b)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		return b, nil
+	}
+
+	// MSSQL: allows Limit() without Order() as per https://stackoverflow.com/a/36156953
+	if q.limit > 0 && fmter.Dialect().Name() == dialect.MSSQL {
+		return append(b, " ORDER BY _temp_sort"...), nil
+	}
+
+	return b, nil
+}
+
+func (q *orderLimitOffsetQuery) setLimit(n int) {
+	q.limit = int32(n)
+}
+
+func (q *orderLimitOffsetQuery) setOffset(n int) {
+	q.offset = int32(n)
+}
+
+func (q *orderLimitOffsetQuery) appendLimitOffset(fmter schema.Formatter, b []byte) (_ []byte, err error) {
+	if fmter.Dialect().Features().Has(feature.OffsetFetch) {
+		if q.limit > 0 && q.offset > 0 {
+			b = append(b, " OFFSET "...)
+			b = strconv.AppendInt(b, int64(q.offset), 10)
+			b = append(b, " ROWS"...)
+
+			b = append(b, " FETCH NEXT "...)
+			b = strconv.AppendInt(b, int64(q.limit), 10)
+			b = append(b, " ROWS ONLY"...)
+		} else if q.limit > 0 {
+			b = append(b, " OFFSET 0 ROWS"...)
+
+			b = append(b, " FETCH NEXT "...)
+			b = strconv.AppendInt(b, int64(q.limit), 10)
+			b = append(b, " ROWS ONLY"...)
+		} else if q.offset > 0 {
+			b = append(b, " OFFSET "...)
+			b = strconv.AppendInt(b, int64(q.offset), 10)
+			b = append(b, " ROWS"...)
+		}
+	} else {
+		if q.limit > 0 {
+			b = append(b, " LIMIT "...)
+			b = strconv.AppendInt(b, int64(q.limit), 10)
+		}
+		if q.offset > 0 {
+			b = append(b, " OFFSET "...)
+			b = strconv.AppendInt(b, int64(q.offset), 10)
+		}
+	}
+
+	return b, nil
+}

query_delete.go

@@ -3,6 +3,7 @@ package bun
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"time"
 
 	"github.com/uptrace/bun/dialect/feature"
@@ -12,6 +13,7 @@ import (
 
 type DeleteQuery struct {
 	whereBaseQuery
+	orderLimitOffsetQuery
 	returningQuery
 }
 
@@ -120,11 +122,39 @@ func (q *DeleteQuery) WhereAllWithDeleted() *DeleteQuery {
 	return q
 }
 
+func (q *DeleteQuery) Order(orders ...string) *DeleteQuery {
+	if !q.hasFeature(feature.DeleteOrderLimit) {
+		q.err = errors.New("bun: order is not supported for current dialect")
+		return q
+	}
+	q.addOrder(orders...)
+	return q
+}
+
+func (q *DeleteQuery) OrderExpr(query string, args ...interface{}) *DeleteQuery {
+	if !q.hasFeature(feature.DeleteOrderLimit) {
+		q.err = errors.New("bun: order is not supported for current dialect")
+		return q
+	}
+	q.addOrderExpr(query, args...)
+	return q
+}
+
 func (q *DeleteQuery) ForceDelete() *DeleteQuery {
 	q.flags = q.flags.Set(forceDeleteFlag)
 	return q
 }
 
+// ------------------------------------------------------------------------------
+func (q *DeleteQuery) Limit(n int) *DeleteQuery {
+	if !q.hasFeature(feature.DeleteOrderLimit) {
+		q.err = errors.New("bun: limit is not supported for current dialect")
+		return q
+	}
+	q.setLimit(n)
+	return q
+}
+
 //------------------------------------------------------------------------------
 
 // Returning adds a RETURNING clause to the query.
@@ -203,6 +233,20 @@ func (q *DeleteQuery) AppendQuery(fmter schema.Formatter, b []byte) (_ []byte, e
 		return nil, err
 	}
 
+	if q.hasMultiTables() && (len(q.order) > 0 || q.limit > 0) {
+		return nil, errors.New("bun: can't use ORDER or LIMIT with multiple tables")
+	}
+
+	b, err = q.appendOrder(fmter, b)
+	if err != nil {
+		return nil, err
+	}
+
+	b, err = q.appendLimitOffset(fmter, b)
+	if err != nil {
+		return nil, err
+	}
+
 	if q.hasFeature(feature.Returning) && q.hasReturning() {
 		b = append(b, " RETURNING "...)
 		b, err = q.appendReturning(fmter, b)