Merge pull request #2115 from ninedraft/sql-err-no-rows

Use sql.ErrNoRows as value for pgx.ErrNoRows

conn.go

@@ -3,6 +3,7 @@ package pgx
 import (
  "context"
  "crypto/sha256"
+ "database/sql"
  "encoding/hex"
  "errors"
  "fmt"
@@ -102,11 +103,27 @@ func (ident Identifier) Sanitize() string {
 
 var (
  // ErrNoRows occurs when rows are expected but none are returned.
- ErrNoRows = errors.New("no rows in result set")
+ ErrNoRows = newProxyErr(sql.ErrNoRows, "no rows in result set")
  // ErrTooManyRows occurs when more rows than expected are returned.
  ErrTooManyRows = errors.New("too many rows in result set")
 )
 
+func newProxyErr(background error, msg string) error {
+ return &proxyError{
+ msg: msg,
+ background: background,
+ }
+}
+
+type proxyError struct {
+ msg string
+ background error
+}
+
+func (err *proxyError) Error() string { return err.msg }
+
+func (err *proxyError) Unwrap() error { return err.background }
+
 var (
  errDisabledStatementCache = fmt.Errorf("cannot use QueryExecModeCacheStatement with disabled statement cache")
  errDisabledDescriptionCache = fmt.Errorf("cannot use QueryExecModeCacheDescribe with disabled description cache")

conn_test.go

@@ -3,6 +3,7 @@ package pgx_test
 import (
  "bytes"
  "context"
+ "database/sql"
  "os"
  "strings"
  "sync"
@@ -1408,3 +1409,13 @@ func TestConnDeallocateInvalidatedCachedStatementsInTransactionWithBatch(t *test
 
  ensureConnValid(t, conn)
 }
+
+func TestErrNoRows(t *testing.T) {
+ t.Parallel()
+
+ // ensure we preserve old error message
+ require.Equal(t, "no rows in result set", pgx.ErrNoRows.Error())
+
+ require.ErrorIs(t, pgx.ErrNoRows, sql.ErrNoRows, "pgx.ErrNowRows must match sql.ErrNoRows")
+ require.ErrorIs(t, pgx.ErrNoRows, pgx.ErrNoRows, "sql.ErrNowRows must match pgx.ErrNoRows")
+}