[SQL] Support MySQL IF&IFNULL Function (#588)

pkg/runtime/function/if.go

@@ -0,0 +1,70 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package function
+
+import (
+	"context"
+)
+
+import (
+	"github.com/pkg/errors"
+)
+
+import (
+	"github.com/arana-db/arana/pkg/proto"
+)
+
+// FuncIf is  https://dev.mysql.com/doc/refman/5.6/en/flow-control-functions.html#function_if
+const FuncIf = "IF"
+
+var _ proto.Func = (*ifFunc)(nil)
+
+func init() {
+	proto.RegisterFunc(FuncIf, ifFunc{})
+}
+
+type ifFunc struct{}
+
+func (i ifFunc) Apply(ctx context.Context, inputs ...proto.Valuer) (proto.Value, error) {
+	val1, err := inputs[0].Value(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	val2, err := inputs[1].Value(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	val3, err := inputs[2].Value(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	if val1 == nil {
+		return val3, nil
+	}
+	if v, _ := val1.Int64(); v != 0 {
+		if val2 != nil {
+			return val2, nil
+		}
+	}
+	return val3, nil
+}
+
+func (i ifFunc) NumInput() int {
+	return 3
+}

pkg/runtime/function/if_null.go

@@ -0,0 +1,61 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package function
+
+import (
+	"context"
+)
+
+import (
+	"github.com/pkg/errors"
+)
+
+import (
+	"github.com/arana-db/arana/pkg/proto"
+)
+
+// FuncIfNull is https://dev.mysql.com/doc/refman/5.6/en/flow-control-functions.html#function_ifnull
+const FuncIfNull = "IFNULL"
+
+var _ proto.Func = (*ifNullFunc)(nil)
+
+func init() {
+	proto.RegisterFunc(FuncIfNull, ifNullFunc{})
+}
+
+type ifNullFunc struct{}
+
+func (i ifNullFunc) Apply(ctx context.Context, inputs ...proto.Valuer) (proto.Value, error) {
+	val1, err := inputs[0].Value(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	val2, err := inputs[1].Value(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	if val1 != nil {
+		return val1, nil
+	}
+	return val2, nil
+
+}
+
+func (i ifNullFunc) NumInput() int {
+	return 2
+}

pkg/runtime/function/if_null_test.go

@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package function
+
+import (
+	"context"
+	"fmt"
+	"testing"
+)
+
+import (
+	"github.com/shopspring/decimal"
+	"github.com/stretchr/testify/assert"
+)
+
+import (
+	"github.com/arana-db/arana/pkg/proto"
+)
+
+// FuncIFNULL is https://dev.mysql.com/doc/refman/5.6/en/flow-control-functions.html#function_ifnull
+func TestIfNull(t *testing.T) {
+	fn := proto.MustGetFunc(FuncIfNull)
+	assert.Equal(t, 2, fn.NumInput())
+	type tt struct {
+		inFirst  proto.Value
+		inSecond proto.Value
+		want     proto.Value
+	}
+	for _, v := range []tt{
+		{nil, proto.NewValueInt64(2), proto.NewValueInt64(2)},
+		{nil, proto.NewValueString("yes"), proto.NewValueString("yes")},
+		{nil, proto.NewValueBool(true), proto.NewValueBool(true)},
+		{nil, proto.NewValueFloat64(9.009123), proto.NewValueFloat64(9.009123)},
+		{nil, proto.NewValueDecimal(decimal.NewFromInt(8080)), proto.NewValueDecimal(decimal.NewFromInt(8080))},
+		{proto.NewValueInt64(2), proto.NewValueFloat64(9.009123), proto.NewValueInt64(2)},
+		{proto.NewValueString("yes"), proto.NewValueInt64(2), proto.NewValueString("yes")},
+		{proto.NewValueBool(true), proto.NewValueFloat64(9.009123), proto.NewValueBool(true)},
+		{proto.NewValueFloat64(9.009123), proto.NewValueBool(true), proto.NewValueFloat64(9.009123)},
+		{proto.NewValueDecimal(decimal.NewFromInt(8080)), proto.NewValueFloat64(9.009123), proto.NewValueDecimal(decimal.NewFromInt(8080))},
+	} {
+		t.Run(fmt.Sprint(v.inFirst), func(t *testing.T) {
+			out, err := fn.Apply(context.Background(), proto.ToValuer(v.inFirst), proto.ToValuer(v.inSecond))
+			assert.NoError(t, err)
+			assert.Equal(t, v.want, out)
+		})
+	}
+}

pkg/runtime/function/if_test.go

@@ -0,0 +1,71 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package function
+
+import (
+	"context"
+	"fmt"
+	"testing"
+)
+
+import (
+	"github.com/shopspring/decimal"
+	"github.com/stretchr/testify/assert"
+)
+
+import (
+	"github.com/arana-db/arana/pkg/proto"
+)
+
+// FuncIf is  https://dev.mysql.com/doc/refman/5.6/en/flow-control-functions.html#function_if
+func TestIf(t *testing.T) {
+	fn := proto.MustGetFunc(FuncIf)
+	assert.Equal(t, 3, fn.NumInput())
+	type tt struct {
+		inFirst  proto.Value
+		inSecond proto.Value
+		inThird  proto.Value
+		want     proto.Value
+	}
+	for _, v := range []tt{
+		{proto.NewValueBool(true), proto.NewValueInt64(1), proto.NewValueInt64(2), proto.NewValueInt64(1)},
+		{proto.NewValueBool(true), proto.NewValueString("yes"), proto.NewValueString("no"), proto.NewValueString("yes")},
+		{proto.NewValueBool(true), proto.NewValueFloat64(0.00000000001), proto.NewValueFloat64(0.00000000002), proto.NewValueFloat64(0.00000000001)},
+		{proto.NewValueBool(true), proto.NewValueDecimal(decimal.NewFromInt(0)), proto.NewValueDecimal(decimal.NewFromInt(1)), proto.NewValueDecimal(decimal.NewFromInt(0))},
+		{proto.NewValueBool(true), proto.NewValueString("yes"), proto.NewValueFloat64(0.00000000001), proto.NewValueString("yes")},
+		{proto.NewValueBool(true), proto.NewValueFloat64(0.00000000001), proto.NewValueDecimal(decimal.NewFromInt(200)), proto.NewValueFloat64(0.00000000001)},
+		{proto.NewValueBool(true), proto.NewValueDecimal(decimal.NewFromInt(1)), proto.NewValueInt64(2), proto.NewValueDecimal(decimal.NewFromInt(1))},
+		{proto.NewValueBool(true), nil, proto.NewValueInt64(2), proto.NewValueInt64(2)},
+		{proto.NewValueBool(true), nil, proto.NewValueString("no"), proto.NewValueString("no")},
+		{proto.NewValueBool(false), proto.NewValueInt64(1), proto.NewValueInt64(2), proto.NewValueInt64(2)},
+		{proto.NewValueBool(false), proto.NewValueString("yes"), proto.NewValueString("no"), proto.NewValueString("no")},
+		{proto.NewValueBool(false), proto.NewValueFloat64(0.00000000001), proto.NewValueFloat64(0.00000000002), proto.NewValueFloat64(0.00000000002)},
+		{proto.NewValueBool(false), proto.NewValueDecimal(decimal.NewFromInt(0)), proto.NewValueDecimal(decimal.NewFromInt(1)), proto.NewValueDecimal(decimal.NewFromInt(1))},
+		{proto.NewValueBool(false), proto.NewValueString("yes"), proto.NewValueFloat64(0.00000000001), proto.NewValueFloat64(0.00000000001)},
+		{proto.NewValueBool(false), proto.NewValueFloat64(0.00000000001), proto.NewValueDecimal(decimal.NewFromInt(200)), proto.NewValueDecimal(decimal.NewFromInt(200))},
+		{proto.NewValueBool(false), proto.NewValueDecimal(decimal.NewFromInt(1)), proto.NewValueInt64(2), proto.NewValueInt64(2)},
+		{nil, proto.NewValueDecimal(decimal.NewFromInt(1)), proto.NewValueInt64(2), proto.NewValueInt64(2)},
+		{nil, proto.NewValueDecimal(decimal.NewFromInt(1)), nil, nil},
+	} {
+		t.Run(fmt.Sprint(v.inFirst), func(t *testing.T) {
+			out, err := fn.Apply(context.Background(), proto.ToValuer(v.inFirst), proto.ToValuer(v.inSecond), proto.ToValuer(v.inThird))
+			assert.NoError(t, err)
+			assert.Equal(t, v.want, out)
+		})
+	}
+}