Merge pull request #3152 from dolthub/fulghum/trigger_name_length

Validate trigger name length is not over 96 chars

Author: fulghum

enginetest/queries/trigger_queries.go

@@ -4839,4 +4839,15 @@ var TriggerErrorTests = []ScriptTest{
 		Query:       "create trigger trig before insert on v for each row set b = 1",
 		ExpectedErr: sql.ErrExpectedTableFoundView,
 	},
+	{
+		// NOTE: We limit trigger names to 96 chars. This is more than MySQL allows (64 chars).
+		Name: "trigger name length over limit",
+		SetUpScript: []string{
+			"CREATE TABLE example_table (id INT AUTO_INCREMENT PRIMARY KEY, value VARCHAR(50));",
+		},
+		Query: `CREATE TRIGGER this_is_a_very_long_trigger_name_that_is_purposefully_made_to_be_exactly_one_hundred_characters_long
+				BEFORE INSERT ON example_table
+				FOR EACH ROW BEGIN SET NEW.value = UPPER(NEW.value); END;`,
+		ExpectedErr: sql.ErrIdentifierIsTooLong,
+	},
 }

sql/analyzer/triggers.go

@@ -28,6 +28,11 @@ import (
 	"github.com/dolthub/go-mysql-server/sql/transform"
 )
 
+// maxTriggerNameLength is the maximum length for the name of a trigger. Note that MySQL applies a limit of 64 characters,
+// but we allow 96 characters to avoid breaking customers who were relying on the previous behavior where we didn't
+// check the length.
+const maxTriggerNameLength = 96
+
 // validateCreateTrigger handles CreateTrigger nodes, resolving references to "old" and "new" table references in
 // the trigger body. Also validates that these old and new references are being used appropriately -- they are only
 // valid for certain kinds of triggers and certain statements.
@@ -37,6 +42,10 @@ func validateCreateTrigger(ctx *sql.Context, a *Analyzer, node sql.Node, scope *
 		return node, transform.SameTree, nil
 	}
 
+	if len(ct.TriggerName) > maxTriggerNameLength {
+		return node, transform.SameTree, sql.ErrIdentifierIsTooLong.New(ct.TriggerName)
+	}
+
 	// We just want to verify that the trigger is correctly defined before creating it. If it is, we replace the
 	// UnresolvedColumn expressions with placeholder expressions that say they are Resolved().
 	// TODO: this might work badly for databases with tables named new and old. Needs tests.

sql/errors.go

@@ -499,6 +499,9 @@ var (
 	// ErrInvalidIdentifier is returned when an identifier is invalid
 	ErrInvalidIdentifier = errors.NewKind("invalid identifier: `%s`")
 
+	// ErrIdentifierIsTooLong is returned when creating a resource, but the identifier is longer than a name limit
+	ErrIdentifierIsTooLong = errors.NewKind("Identifier name '%s' is too long")
+
 	// ErrInvalidArgument is returned when an argument to a function is invalid.
 	ErrInvalidArgument = errors.NewKind("Invalid argument to %s")
 

sql/information_schema/information_schema.go

@@ -698,7 +698,9 @@ var tablespacesExtensionsSchema = Schema{
 var triggersSchema = Schema{
 	{Name: "TRIGGER_CATALOG", Type: types.MustCreateString(sqltypes.VarChar, 64, Collation_Information_Schema_Default), Default: nil, Nullable: true, Source: TriggersTableName},
 	{Name: "TRIGGER_SCHEMA", Type: types.MustCreateString(sqltypes.VarChar, 64, Collation_Information_Schema_Default), Default: nil, Nullable: true, Source: TriggersTableName},
-	{Name: "TRIGGER_NAME", Type: types.MustCreateString(sqltypes.VarChar, 64, Collation_Information_Schema_Default), Default: nil, Nullable: false, Source: TriggersTableName},
+	// NOTE: MySQL limits trigger names to 64 characters, but we limit them to 96 chars to avoid breaking existing customers who were
+	//       relying on us not enforcing the 64 character limit. This is a good candidate to change in a future major version bump.
+	{Name: "TRIGGER_NAME", Type: types.MustCreateString(sqltypes.VarChar, 96, Collation_Information_Schema_Default), Default: nil, Nullable: false, Source: TriggersTableName},
 	{Name: "EVENT_MANIPULATION", Type: types.MustCreateEnumType([]string{"INSERT", "UPDATE", "DELETE"}, Collation_Information_Schema_Default), Default: nil, Nullable: false, Source: TriggersTableName},
 	{Name: "EVENT_OBJECT_CATALOG", Type: types.MustCreateString(sqltypes.VarChar, 64, Collation_Information_Schema_Default), Default: nil, Nullable: true, Source: TriggersTableName},
 	{Name: "EVENT_OBJECT_SCHEMA", Type: types.MustCreateString(sqltypes.VarChar, 64, Collation_Information_Schema_Default), Default: nil, Nullable: true, Source: TriggersTableName},