perf enhancement

qry_insert.go

@@ -5,7 +5,7 @@ package pgm
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"strconv"
 	"strings"
 
@@ -84,21 +84,28 @@ func (q *insertQry) DoNothing() Execute {
 }
 
 func (q *insertQry) DoUpdate(fields ...Field) Execute {
-	var sb strings.Builder
+	sb := getSB()
+	defer putSB(sb)
+
+	sb.WriteString("DO UPDATE SET ")
 	for i, f := range fields {
 		col := f.Name()
-		if i == 0 {
-			fmt.Fprintf(&sb, "%s = EXCLUDED.%s", col, col)
-		} else {
-			fmt.Fprintf(&sb, ", %s = EXCLUDED.%s", col, col)
+		if i > 0 {
+			sb.WriteString(", ")
 		}
+		sb.WriteString(col)
+		sb.WriteString(" = EXCLUDED.")
+		sb.WriteString(col)
 	}
 
-	q.conflictAction = "DO UPDATE SET " + sb.String()
+	q.conflictAction = sb.String()
 	return q
 }
 
 func (q *insertQry) Exec(ctx context.Context) error {
+	if len(q.fields) == 0 {
+		return errors.New("insert query has no fields to insert: call Set() before Exec()")
+	}
 	_, err := poolPGX.Load().Exec(ctx, q.String(), q.args...)
 	if err != nil {
 		return err
@@ -107,6 +114,9 @@ func (q *insertQry) Exec(ctx context.Context) error {
 }
 
 func (q *insertQry) ExecTx(ctx context.Context, tx pgx.Tx) error {
+	if len(q.fields) == 0 {
+		return errors.New("insert query has no fields to insert: call Set() before ExecTx()")
+	}
 	_, err := tx.Exec(ctx, q.String(), q.args...)
 	if err != nil {
 		return err
@@ -116,10 +126,16 @@ func (q *insertQry) ExecTx(ctx context.Context, tx pgx.Tx) error {
 }
 
 func (q *insertQry) First(ctx context.Context, dest ...any) error {
+	if len(q.fields) == 0 {
+		return errors.New("insert query has no fields to insert: call Set() before First()")
+	}
 	return poolPGX.Load().QueryRow(ctx, q.String(), q.args...).Scan(dest...)
 }
 
 func (q *insertQry) FirstTx(ctx context.Context, tx pgx.Tx, dest ...any) error {
+	if len(q.fields) == 0 {
+		return errors.New("insert query has no fields to insert: call Set() before FirstTx()")
+	}
 	return tx.QueryRow(ctx, q.String(), q.args...).Scan(dest...)
 }