feat: allow setting a query comment through a context value

query_column_add.go

@@ -137,6 +137,9 @@ func (q *AddColumnQuery) Exec(ctx context.Context, dest ...interface{}) (sql.Res
 		return nil, feature.NewNotSupportError(feature.AlterColumnExists)
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err

query_column_drop.go

@@ -129,6 +129,9 @@ func (q *DropColumnQuery) AppendQuery(fmter schema.Formatter, b []byte) (_ []byt
 //------------------------------------------------------------------------------
 
 func (q *DropColumnQuery) Exec(ctx context.Context, dest ...interface{}) (sql.Result, error) {
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err

query_delete.go

@@ -321,6 +321,9 @@ func (q *DeleteQuery) scanOrExec(
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	// Generate the query before checking hasReturning.
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {

query_index_create.go

@@ -248,6 +248,9 @@ func (q *CreateIndexQuery) AppendQuery(fmter schema.Formatter, b []byte) (_ []by
 //------------------------------------------------------------------------------
 
 func (q *CreateIndexQuery) Exec(ctx context.Context, dest ...interface{}) (sql.Result, error) {
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err

query_index_drop.go

@@ -115,6 +115,9 @@ func (q *DropIndexQuery) AppendQuery(fmter schema.Formatter, b []byte) (_ []byte
 //------------------------------------------------------------------------------
 
 func (q *DropIndexQuery) Exec(ctx context.Context, dest ...interface{}) (sql.Result, error) {
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err

query_insert.go

@@ -586,6 +586,9 @@ func (q *InsertQuery) scanOrExec(
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	// Generate the query before checking hasReturning.
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {

query_merge.go

@@ -243,6 +243,9 @@ func (q *MergeQuery) scanOrExec(
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	// Generate the query before checking hasReturning.
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {

query_raw.go

@@ -67,6 +67,9 @@ func (q *RawQuery) scanOrExec(
 		}
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	query := q.db.format(q.query, q.args)
 	var res sql.Result
 

query_select.go

@@ -791,6 +791,9 @@ func (q *SelectQuery) Rows(ctx context.Context) (*sql.Rows, error) {
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err
@@ -812,6 +815,9 @@ func (q *SelectQuery) Exec(ctx context.Context, dest ...interface{}) (res sql.Re
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err
@@ -872,6 +878,9 @@ func (q *SelectQuery) scanResult(ctx context.Context, dest ...interface{}) (sql.
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err
@@ -924,6 +933,9 @@ func (q *SelectQuery) Count(ctx context.Context) (int, error) {
 		return 0, q.err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	qq := countQuery{q}
 
 	queryBytes, err := qq.AppendQuery(q.db.fmter, nil)
@@ -1028,6 +1040,9 @@ func (q *SelectQuery) Exists(ctx context.Context) (bool, error) {
 }
 
 func (q *SelectQuery) selectExists(ctx context.Context) (bool, error) {
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	qq := selectExistsQuery{q}
 
 	queryBytes, err := qq.AppendQuery(q.db.fmter, nil)
@@ -1047,6 +1062,9 @@ func (q *SelectQuery) selectExists(ctx context.Context) (bool, error) {
 }
 
 func (q *SelectQuery) whereExists(ctx context.Context) (bool, error) {
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	qq := whereExistsQuery{q}
 
 	queryBytes, err := qq.AppendQuery(q.db.fmter, nil)

query_table_create.go

@@ -358,6 +358,9 @@ func (q *CreateTableQuery) Exec(ctx context.Context, dest ...interface{}) (sql.R
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err

query_table_drop.go

@@ -123,6 +123,9 @@ func (q *DropTableQuery) Exec(ctx context.Context, dest ...interface{}) (sql.Res
 		}
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err

query_table_truncate.go

@@ -136,6 +136,9 @@ func (q *TruncateTableQuery) AppendQuery(
 //------------------------------------------------------------------------------
 
 func (q *TruncateTableQuery) Exec(ctx context.Context, dest ...interface{}) (sql.Result, error) {
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {
 		return nil, err

query_update.go

@@ -556,6 +556,9 @@ func (q *UpdateQuery) scanOrExec(
 		return nil, err
 	}
 
+	// if a comment is propagated via the context, use it
+	setCommentFromContext(ctx, q)
+
 	// Generate the query before checking hasReturning.
 	queryBytes, err := q.AppendQuery(q.db.fmter, q.db.makeQueryBytes())
 	if err != nil {

util.go

@@ -1,6 +1,7 @@
 package bun
 
 import (
+	"context"
 	"fmt"
 	"reflect"
 	"strings"
@@ -86,3 +87,26 @@ func appendComment(b []byte, name string) []byte {
 	name = strings.ReplaceAll(name, `*/`, `*\/`)
 	return append(b, fmt.Sprintf("/* %s */ ", name)...)
 }
+
+// queryCommentCtxKey is a context key for setting a query comment on a context instead of calling the Comment("...") API directly
+type queryCommentCtxKey struct{}
+
+// ContextWithComment returns a context that includes a comment that may be included in a query for debugging
+//
+// If a context with an attached query is used, a comment set by the Comment("...") API will be overwritten.
+func ContextWithComment(ctx context.Context, comment string) context.Context {
+	return context.WithValue(ctx, queryCommentCtxKey{}, comment)
+}
+
+// commenter describes the Comment interface implemented by all of the query types
+type commenter[T any] interface {
+	Comment(string) T
+}
+
+// setCommentFromContext sets the comment on the given query from the supplied context if one is set using the Comment(...) method.
+func setCommentFromContext[T any](ctx context.Context, q commenter[T]) {
+	s, _ := ctx.Value(queryCommentCtxKey{}).(string)
+	if s != "" {
+		q.Comment(s)
+	}
+}