From 777d73d51ef0f1f6f1c25f498f33fcee2e090d01 Mon Sep 17 00:00:00 2001
From: Philip Witty <philip.witty@gmail.com>
Date: Fri, 10 Sep 2021 14:40:22 +0200
Subject: [PATCH] Add support for LOWER function

---
 spanner/spannertest/funcs.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/spanner/spannertest/funcs.go b/spanner/spannertest/funcs.go
index bb9b1359a9cc..c4399ddcc8b7 100644
--- a/spanner/spannertest/funcs.go
+++ b/spanner/spannertest/funcs.go
@@ -52,6 +52,14 @@ var functions = map[string]function{
 			return strings.HasPrefix(s, prefix), spansql.Type{Base: spansql.Bool}, nil
 		},
 	},
+	"LOWER": {
+		Eval: func(values []interface{}) (interface{}, spansql.Type, error) {
+			if len(values) != 1 {
+				return nil, spansql.Type{}, status.Error(codes.InvalidArgument, "No matching signature for function LOWER for the given argument types")
+			}
+			return strings.ToLower(values[0].(string)), spansql.Type{Base: spansql.String}, nil
+		},
+	},
 }
 
 type aggregateFunc struct {