From 4c7c61e8200faad28bd7deb3664d92a893ed4146 Mon Sep 17 00:00:00 2001
From: Jan Bader <jan@javil.eu>
Date: Wed, 23 Feb 2022 19:21:56 +0000
Subject: [PATCH] Add string method to numeric

---
 postgres/numeric.go | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/postgres/numeric.go b/postgres/numeric.go
index f750a7b..cf8dea4 100644
--- a/postgres/numeric.go
+++ b/postgres/numeric.go
@@ -92,6 +92,43 @@ func (n Numeric) Add(other Numeric) Numeric {
 	panic("Cannot add with different exponents")
 }
 
+func (n Numeric) String() string {
+	if n.Int.Int64() == 0 {
+		return "0"
+	}
+
+	s := fmt.Sprintf("%d", n.Int)
+	bytes := []byte(s)
+
+	exp := n.Exp
+	for exp > 0 {
+		bytes = append(bytes, byte('0'))
+		exp--
+	}
+
+	if exp == 0 {
+		return string(bytes)
+	}
+
+	length := int32(len(bytes))
+	var bytesWithSeparator []byte
+
+	exp = -exp
+	for length <= exp {
+		bytes = append(bytes, byte('0'))
+		length++
+	}
+
+	split := length - exp
+	bytesWithSeparator = append(bytesWithSeparator, bytes[:split]...)
+	if split == 1 && n.Int.Int64() < 0 {
+		bytesWithSeparator = append(bytesWithSeparator, byte('0'))
+	}
+	bytesWithSeparator = append(bytesWithSeparator, byte('.'))
+	bytesWithSeparator = append(bytesWithSeparator, bytes[split:]...)
+	return string(bytesWithSeparator)
+}
+
 func (n Numeric) MarshalJSON() ([]byte, error) {
 	if n.Int.Int64() == 0 {
 		return []byte("0"), nil