postgres: fix decimal conversions

Cargo.lock

@@ -40,6 +40,12 @@ dependencies = [
  "threadpool",
 ]
 
+[[package]]
+name = "ahash"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f6789e291be47ace86a60303502173d84af8327e3627ecf334356ee0f87a164c"
+
 [[package]]
 name = "ahash"
 version = "0.5.8"
@@ -1018,6 +1024,18 @@ name = "hashbrown"
 version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d7afe4a420e3fe79967a00898cc1f4db7c8a49a9333a29f8a4bd76a253d5cd04"
+dependencies = [
+ "ahash 0.4.6",
+]
+
+[[package]]
+name = "hashlink"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d99cf782f0dc4372d26846bec3de7804ceb5df083c2d4462c0b8d2330e894fa8"
+dependencies = [
+ "hashbrown",
+]
 
 [[package]]
 name = "heck"
@@ -1197,12 +1215,6 @@ dependencies = [
  "vcpkg",
 ]
 
-[[package]]
-name = "linked-hash-map"
-version = "0.5.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8dd5a6d5999d9907cda8ed67bbd137d3af8085216c2ac62de5be860bd41f304a"
-
 [[package]]
 name = "lock_api"
 version = "0.4.1"
@@ -1221,15 +1233,6 @@ dependencies = [
  "cfg-if 0.1.10",
 ]
 
-[[package]]
-name = "lru-cache"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "31e24f1ad8321ca0e8a1e0ac13f23cb668e6f5466c2c57319f6a5cf1cc8e3b1c"
-dependencies = [
- "linked-hash-map",
-]
-
 [[package]]
 name = "maplit"
 version = "1.0.2"
@@ -2200,7 +2203,7 @@ dependencies = [
 name = "sqlx-core"
 version = "0.4.0"
 dependencies = [
- "ahash",
+ "ahash 0.5.8",
  "atoi",
  "base64 0.13.0",
  "bigdecimal",
@@ -2220,6 +2223,7 @@ dependencies = [
  "futures-core",
  "futures-util",
  "generic-array",
+ "hashlink",
  "hex",
  "hmac",
  "ipnetwork",
@@ -2227,7 +2231,6 @@ dependencies = [
  "libc",
  "libsqlite3-sys",
  "log",
- "lru-cache",
  "md-5",
  "memchr",
  "num-bigint 0.3.1",

sqlx-core/src/postgres/types/bigdecimal.rs

@@ -115,9 +115,11 @@ impl TryFrom<&'_ BigDecimal> for PgNumeric {
         let mut digits = Vec::with_capacity(digits_len);
 
         if let Some(first) = base_10.get(..offset) {
-            if offset != 0 {
+            if !first.is_empty() {
                 digits.push(base_10_to_10000(first));
             }
+        } else if offset != 0 {
+            digits.push(base_10_to_10000(&base_10) * 10i16.pow(3 - base_10.len() as u32));
         }
 
         if let Some(rest) = base_10.get(offset..) {
@@ -275,6 +277,34 @@ mod bigdecimal_to_pgnumeric {
         );
     }
 
+    #[test]
+    fn one_hundredth() {
+        let one_hundredth: BigDecimal = "0.01".parse().unwrap();
+        assert_eq!(
+            PgNumeric::try_from(&one_hundredth).unwrap(),
+            PgNumeric::Number {
+                sign: PgNumericSign::Positive,
+                scale: 2,
+                weight: -1,
+                digits: vec![100]
+            }
+        );
+    }
+
+    #[test]
+    fn twelve_thousandths() {
+        let twelve_thousandths: BigDecimal = "0.012".parse().unwrap();
+        assert_eq!(
+            PgNumeric::try_from(&twelve_thousandths).unwrap(),
+            PgNumeric::Number {
+                sign: PgNumericSign::Positive,
+                scale: 3,
+                weight: -1,
+                digits: vec![120]
+            }
+        );
+    }
+
     #[test]
     fn decimal_1() {
         let decimal: BigDecimal = "1.2345".parse().unwrap();