Cherry-pick 5fd70c4 with conflicts

go/vt/vtgate/engine/projection.go

@@ -74,7 +74,11 @@ func (p *Projection) TryExecute(ctx context.Context, vcursor VCursor, bindVars m
  resultRows = append(resultRows, resultRow)
  }
  if wantfields {
+<<<<<<< HEAD
  result.Fields, err = p.evalFields(env, result.Fields, vcursor)
+=======
+ result.Fields, err = p.evalFields(env, result.Fields, vcursor.ConnCollation())
+>>>>>>> 5fd70c4323 (projection: Return correct collation information (#15801))
  if err != nil {
  return nil, err
  }
@@ -95,7 +99,11 @@ func (p *Projection) TryStreamExecute(ctx context.Context, vcursor VCursor, bind
  defer mu.Unlock()
  if wantfields {
  once.Do(func() {
+<<<<<<< HEAD
  fields, err = p.evalFields(env, qr.Fields, vcursor)
+=======
+ fields, err = p.evalFields(env, qr.Fields, vcursor.ConnCollation())
+>>>>>>> 5fd70c4323 (projection: Return correct collation information (#15801))
  if err != nil {
  return
  }
@@ -134,14 +142,26 @@ func (p *Projection) GetFields(ctx context.Context, vcursor VCursor, bindVars ma
  return nil, err
  }
  env := evalengine.NewExpressionEnv(ctx, bindVars, vcursor)
+<<<<<<< HEAD
  qr.Fields, err = p.evalFields(env, qr.Fields, vcursor)
+=======
+ qr.Fields, err = p.evalFields(env, qr.Fields, vcursor.ConnCollation())
+>>>>>>> 5fd70c4323 (projection: Return correct collation information (#15801))
  if err != nil {
  return nil, err
  }
  return qr, nil
 }
 
+<<<<<<< HEAD
 func (p *Projection) evalFields(env *evalengine.ExpressionEnv, infields []*querypb.Field, vcursor VCursor) ([]*querypb.Field, error) {
+=======
+func (p *Projection) evalFields(env *evalengine.ExpressionEnv, infields []*querypb.Field, coll collations.ID) ([]*querypb.Field, error) {
+ // TODO: once the evalengine becomes smart enough, we should be able to remove the
+ // dependency on these fields altogether
+ env.Fields = infields
+
+>>>>>>> 5fd70c4323 (projection: Return correct collation information (#15801))
  var fields []*querypb.Field
  for i, col := range p.Cols {
  q, f, err := env.TypeOf(p.Exprs[i], infields)
@@ -157,11 +177,25 @@ func (p *Projection) evalFields(env *evalengine.ExpressionEnv, infields []*query
  if !sqltypes.IsNull(q) && !f.Nullable() {
  fl |= uint32(querypb.MySqlFlag_NOT_NULL_FLAG)
  }
+ typCol := typ.Collation()
+ if sqltypes.IsTextOrBinary(typ.Type()) && typCol != collations.CollationBinaryID {
+ typCol = coll
+ }
+
  fields = append(fields, &querypb.Field{
+<<<<<<< HEAD
  Name: col,
  Type: q,
  Charset: uint32(cs),
  Flags: fl,
+=======
+ Name: col,
+ Type: typ.Type(),
+ Charset: uint32(typCol),
+ ColumnLength: uint32(typ.Size()),
+ Decimals: uint32(typ.Scale()),
+ Flags: fl,
+>>>>>>> 5fd70c4323 (projection: Return correct collation information (#15801))
  })
  }
  return fields, nil

go/vt/vtgate/engine/projection_test.go

@@ -212,3 +212,41 @@ func TestFields(t *testing.T) {
  })
  }
 }
+
+func TestFieldConversion(t *testing.T) {
+ var testCases = []struct {
+ name string
+ expr string
+ typ querypb.Type
+ collation collations.ID
+ }{
+ {
+ name: `convert different charset`,
+ expr: `_latin1 0xFF`,
+ typ: sqltypes.VarChar,
+ collation: collations.MySQL8().DefaultConnectionCharset(),
+ },
+ }
+
+ for _, testCase := range testCases {
+ t.Run(testCase.name, func(t *testing.T) {
+ arg, err := sqlparser.NewTestParser().ParseExpr(testCase.expr)
+ require.NoError(t, err)
+ bindExpr, err := evalengine.Translate(arg, &evalengine.Config{
+ Environment: vtenv.NewTestEnv(),
+ Collation: collations.MySQL8().DefaultConnectionCharset(),
+ })
+ require.NoError(t, err)
+ proj := &Projection{
+ Cols: []string{"col"},
+ Exprs: []evalengine.Expr{bindExpr},
+ Input: &SingleRow{},
+ noTxNeeded: noTxNeeded{},
+ }
+ qr, err := proj.TryExecute(context.Background(), &noopVCursor{}, nil, true)
+ require.NoError(t, err)
+ assert.Equal(t, testCase.typ, qr.Fields[0].Type)
+ assert.Equal(t, testCase.collation, collations.ID(qr.Fields[0].Charset))
+ })
+ }
+}