SELECT inherits dialect from INSERT in INSERT FROM SELECT construct, fixes #223

dialect/mysql/mysql_test.go

@@ -539,6 +539,27 @@ func (mt *mysqlTest) TestWindowFunction() {
 	mt.Error(ds.WithDialect("mysql").ScanStructs(&entries), "goqu: adapter does not support window function clause")
 }
 
+func (mt *mysqlTest) TestInsertFromSelect() {
+	ds := mt.db.From("entry")
+
+	subquery := goqu.Select(
+		goqu.V(11),
+		goqu.V(11),
+		goqu.C("float"),
+		goqu.C("string"),
+		goqu.C("time"),
+		goqu.C("bool"),
+		goqu.C("bytes"),
+	).From(goqu.T("entry")).Where(goqu.C("int").Eq(9))
+
+	query := ds.Insert().Cols().FromQuery(subquery)
+	_, _, err := query.ToSQL()
+
+	mt.NoError(err)
+	_, err = query.Executor().Exec()
+	mt.NoError(err)
+}
+
 func TestMysqlSuite(t *testing.T) {
 	suite.Run(t, new(mysqlTest))
 }

insert_dataset.go

@@ -1,6 +1,8 @@
 package goqu
 
 import (
+	"fmt"
+
 	"github.com/doug-martin/goqu/v9/exec"
 	"github.com/doug-martin/goqu/v9/exp"
 	"github.com/doug-martin/goqu/v9/internal/errors"
@@ -143,6 +145,17 @@ func (id *InsertDataset) ColsAppend(cols ...interface{}) *InsertDataset {
 
 // Adds a subquery to the insert. See examples.
 func (id *InsertDataset) FromQuery(from exp.AppendableExpression) *InsertDataset {
+	if sds, ok := from.(*SelectDataset); ok {
+		if sds.dialect != GetDialect("default") && id.Dialect() != sds.dialect {
+			panic(
+				fmt.Errorf(
+					"incompatible dialects for INSERT (%q) and SELECT (%q)",
+					id.dialect.Dialect(), sds.dialect.Dialect(),
+				),
+			)
+		}
+		sds.dialect = id.dialect
+	}
 	return id.copy(id.clauses.SetFrom(from))
 }
 

insert_dataset_test.go

@@ -207,6 +207,43 @@ func (ids *insertDatasetSuite) TestFromQuery() {
 	)
 }
 
+func (ids *insertDatasetSuite) TestFromQueryDialectInheritance() {
+	md := new(mocks.SQLDialect)
+	md.On("Dialect").Return("dialect")
+
+	ids.Run("ok, default dialect is replaced with insert dialect", func() {
+		bd := Insert("items").SetDialect(md).FromQuery(From("other_items"))
+		ids.Require().Equal(md, bd.clauses.From().(*SelectDataset).Dialect())
+	})
+
+	ids.Run("ok, insert and select dialects coincide", func() {
+		bd := Insert("items").SetDialect(md).FromQuery(From("other_items").SetDialect(md))
+		ids.Require().Equal(md, bd.clauses.From().(*SelectDataset).Dialect())
+	})
+
+	ids.Run("ok, insert and select dialects are default", func() {
+		bd := Insert("items").FromQuery(From("other_items"))
+		ids.Require().Equal(GetDialect("default"), bd.clauses.From().(*SelectDataset).Dialect())
+	})
+
+	ids.Run("panic, insert and select dialects are different", func() {
+		defer func() {
+			r := recover()
+			if r == nil {
+				ids.Fail("there should be a panic")
+			}
+			ids.Require().Equal(
+				"incompatible dialects for INSERT (\"dialect\") and SELECT (\"other_dialect\")",
+				r.(error).Error(),
+			)
+		}()
+
+		otherDialect := new(mocks.SQLDialect)
+		otherDialect.On("Dialect").Return("other_dialect")
+		Insert("items").SetDialect(md).FromQuery(From("otherItems").SetDialect(otherDialect))
+	})
+}
+
 func (ids *insertDatasetSuite) TestVals() {
 	val1 := []interface{}{
 		"a", "b",