chore: import upstream snapshot with attribution

server/node/create_trigger.go

@@ -0,0 +1,199 @@
+// Copyright 2025 Dolthub, Inc.
+//
+// Licensed 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 node
+
+import (
+	"context"
+
+	"github.com/cockroachdb/errors"
+	"github.com/dolthub/go-mysql-server/sql"
+	"github.com/dolthub/go-mysql-server/sql/plan"
+	vitess "github.com/dolthub/vitess/go/vt/sqlparser"
+
+	"github.com/dolthub/doltgresql/core"
+	"github.com/dolthub/doltgresql/core/functions"
+	"github.com/dolthub/doltgresql/core/id"
+	"github.com/dolthub/doltgresql/core/triggers"
+	"github.com/dolthub/doltgresql/server/plpgsql"
+	pgtypes "github.com/dolthub/doltgresql/server/types"
+)
+
+// CreateTrigger implements CREATE TRIGGER.
+type CreateTrigger struct {
+	Name       id.Trigger
+	Function   id.Function
+	Replace    bool
+	Timing     triggers.TriggerTiming
+	Events     []triggers.TriggerEvent
+	ForEachRow bool
+	When       []plpgsql.InterpreterOperation
+	Arguments  []string
+	Definition string
+}
+
+var _ sql.ExecSourceRel = (*CreateTrigger)(nil)
+var _ vitess.Injectable = (*CreateTrigger)(nil)
+
+// NewCreateTrigger returns a new *CreateTrigger.
+func NewCreateTrigger(
+	triggerName id.Trigger,
+	functionName id.Function,
+	replace bool,
+	timing triggers.TriggerTiming,
+	events []triggers.TriggerEvent,
+	forEachRow bool,
+	when []plpgsql.InterpreterOperation,
+	arguments []string,
+	definition string) *CreateTrigger {
+	return &CreateTrigger{
+		Name:       triggerName,
+		Function:   functionName,
+		Replace:    replace,
+		Timing:     timing,
+		Events:     events,
+		ForEachRow: forEachRow,
+		When:       when,
+		Arguments:  arguments,
+		Definition: definition,
+	}
+}
+
+// Children implements the interface sql.ExecSourceRel.
+func (c *CreateTrigger) Children() []sql.Node {
+	return nil
+}
+
+// IsReadOnly implements the interface sql.ExecSourceRel.
+func (c *CreateTrigger) IsReadOnly() bool {
+	return false
+}
+
+// Resolved implements the interface sql.ExecSourceRel.
+func (c *CreateTrigger) Resolved() bool {
+	return true
+}
+
+// RowIter implements the interface sql.ExecSourceRel.
+func (c *CreateTrigger) RowIter(ctx *sql.Context, r sql.Row) (sql.RowIter, error) {
+	schema, err := core.GetSchemaName(ctx, nil, c.Name.SchemaName())
+	if err != nil {
+		return nil, err
+	}
+	triggerID := id.NewTrigger(schema, c.Name.TableName(), c.Name.TriggerName())
+	relationType, err := core.GetRelationType(ctx, schema, c.Name.TableName())
+	if err != nil {
+		return nil, err
+	}
+	if relationType == core.RelationType_DoesNotExist {
+		return nil, errors.Errorf(`relation "%s" does not exist`, c.Name.TableName())
+	} else if relationType != core.RelationType_Table {
+		return nil, errors.Errorf(`"%s" is not a table or view`, c.Name.TableName())
+	}
+	function, err := loadFunction(ctx, nil, c.Function)
+	if err != nil {
+		return nil, err
+	}
+	if !function.ID.IsValid() {
+		return nil, errors.Errorf("function %s() does not exist", c.Function.FunctionName())
+	}
+	if function.ReturnType != pgtypes.Trigger.ID {
+		return nil, errors.Errorf(`function %s must return type trigger`, function.ID.FunctionName())
+	}
+	trigCollection, err := core.GetTriggersCollectionFromContext(ctx, ctx.GetCurrentDatabase())
+	if err != nil {
+		return nil, err
+	}
+	if c.Replace && trigCollection.HasTrigger(ctx, triggerID) {
+		if err = trigCollection.DropTrigger(ctx, triggerID); err != nil {
+			return nil, err
+		}
+	}
+	err = trigCollection.AddTrigger(ctx, triggers.Trigger{
+		ID:                  triggerID,
+		Function:            function.ID,
+		Timing:              c.Timing,
+		Events:              c.Events,
+		ForEachRow:          c.ForEachRow,
+		When:                c.When,
+		Deferrable:          triggers.TriggerDeferrable_NotDeferrable,
+		ReferencedTableName: "",
+		Constraint:          false,
+		OldTransitionName:   "",
+		NewTransitionName:   "",
+		Arguments:           c.Arguments,
+		Definition:          c.Definition,
+	})
+	if err != nil {
+		return nil, err
+	}
+	return sql.RowsToRowIter(), nil
+}
+
+// Schema implements the interface sql.ExecSourceRel.
+func (c *CreateTrigger) Schema(ctx *sql.Context) sql.Schema {
+	return nil
+}
+
+// String implements the interface sql.ExecSourceRel.
+func (c *CreateTrigger) String() string {
+	return "CREATE TRIGGER"
+}
+
+// WithChildren implements the interface sql.ExecSourceRel.
+func (c *CreateTrigger) WithChildren(ctx *sql.Context, children ...sql.Node) (sql.Node, error) {
+	return plan.NillaryWithChildren(c, children...)
+}
+
+// WithResolvedChildren implements the interface vitess.Injectable.
+func (c *CreateTrigger) WithResolvedChildren(ctx context.Context, children []any) (any, error) {
+	if len(children) != 0 {
+		return nil, ErrVitessChildCount.New(0, len(children))
+	}
+	return c, nil
+}
+
+// loadFunction loads the function with the given ID from the given collection. If the collection is nil, then this also
+// loads the collection from the context.
+func loadFunction(ctx *sql.Context, funcCollection *functions.Collection, funcID id.Function) (functions.Function, error) {
+	var err error
+	if funcCollection == nil {
+		funcCollection, err = core.GetFunctionsCollectionFromContext(ctx, "")
+		if err != nil {
+			return functions.Function{}, err
+		}
+	}
+	var function functions.Function
+	if len(funcID.SchemaName()) > 0 {
+		function, err = funcCollection.GetFunction(ctx, funcID)
+		if err != nil {
+			return functions.Function{}, err
+		}
+	} else {
+		searchPaths, err := core.SearchPath(ctx)
+		if err != nil {
+			return functions.Function{}, err
+		}
+		for _, searchPath := range searchPaths {
+			function, err = funcCollection.GetFunction(ctx, id.NewFunction(searchPath, funcID.FunctionName()))
+			if err != nil {
+				return functions.Function{}, err
+			}
+			if function.ID.IsValid() {
+				break
+			}
+		}
+	}
+	return function, nil
+}