Added undeclared variable error message

enginetest/queries/queries.go

@@ -11323,6 +11323,10 @@ var ErrorQueries = []QueryErrorTest{
 		Query:       `SELECT * FROM (values row(1,2), row(1,2,3)) t`,
 		ExpectedErr: sql.ErrColValCountMismatch,
 	},
+	{
+		Query:       "SELECT 1 INTO mytable;",
+		ExpectedErr: sql.ErrUndeclaredVariable,
+	},
 }
 
 var BrokenErrorQueries = []QueryErrorTest{

sql/errors.go

@@ -238,6 +238,9 @@ var (
 	// ErrEventDoesNotExist is returned when an event does not exist.
 	ErrEventDoesNotExist = errors.NewKind("Event '%s' does not exist")
 
+	// ErrUndceclaredVariable is return when a variable is undeclared.
+	ErrUndeclaredVariable = errors.NewKind("Undeclared variable: %s")
+
 	// ErrUnknownEvent is returned when a query references an event that doesn't exist
 	ErrUnknownEvent = errors.NewKind("Unknown event '%s'")
 

sql/planbuilder/dml.go

@@ -752,7 +752,7 @@ func (b *Builder) buildInto(inScope *scope, into *ast.Into) {
 			vars[i] = expression.NewUserVar(strings.TrimPrefix(val.String(), "@"))
 		} else {
 			if inScope.proc == nil {
-				err := sql.ErrExternalProcedureMissingContextParam.New(val.String())
+				err := sql.ErrUndeclaredVariable.New(val.String())
 				b.handleErr(err)
 			}
 			col, ok := inScope.proc.GetVar(val.String())