fix(sql): split up datatypes more granular, fixes #462 (#608)

plugins/sql/src/decode/postgres.rs

@@ -17,14 +17,35 @@ pub(crate) fn to_json(v: PgValueRef) -> Result<JsonValue, Error> {
                 JsonValue::Null
             }
         }
-        "FLOAT4" | "FLOAT8" => {
+        "FLOAT4" => {
+            if let Ok(v) = ValueRef::to_owned(&v).try_decode::<f32>() {
+                JsonValue::from(v)
+            } else {
+                JsonValue::Null
+            }
+        }
+        "FLOAT8" => {
             if let Ok(v) = ValueRef::to_owned(&v).try_decode::<f64>() {
                 JsonValue::from(v)
             } else {
                 JsonValue::Null
             }
         }
-        "INT2" | "INT4" | "INT8" => {
+        "INT2" => {
+            if let Ok(v) = ValueRef::to_owned(&v).try_decode::<i16>() {
+                JsonValue::Number(v.into())
+            } else {
+                JsonValue::Null
+            }
+        }
+        "INT4" => {
+            if let Ok(v) = ValueRef::to_owned(&v).try_decode::<i32>() {
+                JsonValue::Number(v.into())
+            } else {
+                JsonValue::Null
+            }
+        }
+        "INT8" => {
             if let Ok(v) = ValueRef::to_owned(&v).try_decode::<i64>() {
                 JsonValue::Number(v.into())
             } else {