Handle 0 rows (#57)

* Handle 0 rows

* Fix for tests

* Update readme

README.md

@@ -454,6 +454,24 @@ file into SQLite.
 So even if you change the query, as long as the file doesn't change,
 the cache is effective.
 
+### Interactive REPL
+
+Use the `-i` or `--interactive` flag to enter an interactive REPL
+where you can run multiple SQL queries.
+
+```
+$ dsq some-large-file.json -i
+dsq> SELECT COUNT(1) FROM {};
++----------+
+| COUNT(1) |
++----------+
+| 1000 |
++----------+
+(1 row)
+dsq> SELECT * FROM {} WHERE NAME = 'Kevin';
+(0 rows)
+```
+
 ## Supported Data Types
 
 | Name | File Extension(s) | Mime Type | Notes |

main.go

@@ -11,6 +11,7 @@ import (
  "io/ioutil"
  "log"
  "os"
+ "path"
  "path/filepath"
  "regexp"
  "sort"
@@ -97,6 +98,12 @@ func dumpJSONFile(file string, pretty bool, schema bool) error {
  }
  defer fd.Close()
 
+ size := int64(-1)
+ fi, err := fd.Stat()
+ if err == nil {
+ size = fi.Size()
+ }
+
  if schema {
  s, err := runner.ShapeFromFile(file, "doesn't-matter", runner.DefaultShapeMaxBytesToRead, 100)
  if err != nil {
@@ -124,48 +131,57 @@ func dumpJSONFile(file string, pretty bool, schema bool) error {
  return nil
  }
 
- s, err := runner.ShapeFromFile(file, "doesn't-matter", runner.DefaultShapeMaxBytesToRead, 100)
- if err != nil {
- return err
- }
- var columns []string
- for name := range s.ArrayShape.Children.ObjectShape.Children {
- columns = append(columns, name)
- }
- sort.Strings(columns)
+ var rows []map[string]interface{}
+ if size != 0 {
+ s, err := runner.ShapeFromFile(file, "doesn't-matter", runner.DefaultShapeMaxBytesToRead, 100)
+ if err != nil {
+ return err
+ }
+ var columns []string
+ for name := range s.ArrayShape.Children.ObjectShape.Children {
+ columns = append(columns, name)
+ }
+ sort.Strings(columns)
 
- table := tablewriter.NewWriter(os.Stdout)
- table.SetHeader(columns)
- table.SetAutoFormatHeaders(false)
+  table := tablewriter.NewWriter(os.Stdout)
+  table.SetHeader(columns)
+  table.SetAutoFormatHeaders(false)
 
- dec := json.NewDecoder(fd)
- var rows []map[string]interface{}
- err = dec.Decode(&rows)
- if err != nil {
- return err
- }
+ dec := json.NewDecoder(fd)
+ err = dec.Decode(&rows)
+ if err != nil {
+ return err
+ }
 
- for _, objRow := range rows {
- var row []string
- for _, column := range columns {
- var cell string
- switch t := objRow[column].(type) {
- case bool, byte, complex64, complex128, error, float32, float64,
- int, int8, int16, int32, int64,
- uint, uint16, uint32, uint64, uintptr:
- cell = fmt.Sprintf("%#v", t)
- case string:
- cell = t
- default:
- cellBytes, _ := json.Marshal(t)
- cell = string(cellBytes)
+ for _, objRow := range rows {
+ var row []string
+ for _, column := range columns {
+ var cell string
+ switch t := objRow[column].(type) {
+ case bool, byte, complex64, complex128, error, float32, float64,
+ int, int8, int16, int32, int64,
+ uint, uint16, uint32, uint64, uintptr:
+ cell = fmt.Sprintf("%#v", t)
+ case string:
+ cell = t
+ default:
+ cellBytes, _ := json.Marshal(t)
+ cell = string(cellBytes)
+ }
+ row = append(row, cell)
  }
- row = append(row, cell)
+ table.Append(row)
  }
- table.Append(row)
+
+ table.Render()
+ }
+
+ if len(rows) == 1 {
+ fmt.Println("(1 row)")
+ } else {
+ fmt.Printf("(%d rows)\n", len(rows))
  }
 
- table.Render()
  return nil
 }
 
@@ -251,13 +267,6 @@ func runQuery(queryRaw string, project *runner.ProjectState, ec *runner.EvalCont
 }
 
 func repl(project *runner.ProjectState, ec *runner.EvalContext, args *args, files []string) error {
- tempfile, err := ioutil.TempFile("", "dsq-hist")
- if err != nil {
- return err
- }
-
- defer os.Remove(tempfile.Name())
-
  completer := readline.NewPrefixCompleter(
  readline.PcItem("SELECT"),
  readline.PcItem("FROM"),
@@ -277,9 +286,10 @@ func repl(project *runner.ProjectState, ec *runner.EvalContext, args *args, file
  return r, true
  }
 
+ historyFile := path.Join(runner.HOME, "dsq_history")
  l, err := readline.NewEx(&readline.Config{
  Prompt: "dsq> ",
- HistoryFile: tempfile.Name(),
+ HistoryFile: historyFile,
  InterruptPrompt: "^D",
  EOFPrompt: "exit",
  HistorySearchFold: true,

scripts/test.py

@@ -183,7 +183,8 @@ def test(name, to_run, want, fail=False, sort=False, winSkip=False, within_secon
 +----+-------+
 | 1 | Corah |
 | 3 | Minh |
-+----+-------+"""
++----+-------+
+(2 rows)"""
 test("Pretty column order alphabetical", to_run, want)
 
 # Pretty without query
@@ -192,7 +193,8 @@ def test(name, to_run, want, fail=False, sort=False, winSkip=False, within_secon
 | a | b | c |
 +---+---+-------+
 | 1 | 2 | [1,2] |
-+---+---+-------+"""
++---+---+-------+
+(1 row)"""
 test("Pretty works even without query", to_run, want)
 
 # Prints schema pretty