S3 Select: Convert CSV data to JSON (#8464)

pkg/s3select/json/record.go

@@ -87,7 +87,13 @@ func (r *Record) Set(name string, value *sql.Value) error {
 	} else if value.IsNull() {
 		v = nil
 	} else if b, ok := value.ToBytes(); ok {
-		v = RawJSON(b)
+		// This can either be raw json or a CSV value.
+		// Only treat objects and arrays as JSON.
+		if len(b) > 0 && (b[0] == '{' || b[0] == '[') {
+			v = RawJSON(b)
+		} else {
+			v = string(b)
+		}
 	} else if arr, ok := value.ToArray(); ok {
 		v = arr
 	} else {