Add .import command

cmd/genji/shell/command.go

@@ -2,8 +2,11 @@ package shell
 
 import (
 	"context"
+	"encoding/csv"
+	"errors"
 	"fmt"
 	"io"
+	"os"
 	"strings"
 
 	"github.com/genjidb/genji"
@@ -14,13 +17,19 @@ import (
 	"github.com/genjidb/genji/stringutil"
 )
 
-var commands = []struct {
+type command struct {
 	Name        string
 	Options     string
 	DisplayName string
 	Description string
 	Aliases     []string
-}{
+}
+
+func (c *command) Usage() string {
+	return fmt.Sprintf("%s %s", c.DisplayName, c.Options)
+}
+
+var commands = []command{
 	{
 		Name:        ".exit",
 		DisplayName: ".exit or exit",
@@ -52,7 +61,7 @@ var commands = []struct {
 	},
 	{
 		Name:        ".save",
-		Options:     "[badger?] [filename]",
+		Options:     "[badger] [filename]",
 		DisplayName: ".save",
 		Description: "Save database content in the specified file.",
 	},
@@ -62,6 +71,22 @@ var commands = []struct {
 		DisplayName: ".schema",
 		Description: "Show the CREATE statements of all tables or of the selected ones.",
 	},
+	{
+		Name:        ".import",
+		Options:     "TYPE FILE table",
+		DisplayName: ".import",
+		Description: "Import data from a file. Only supported type is 'csv'",
+	},
+}
+
+func getUsage(cmdName string) string {
+	for _, c := range commands {
+		if c.Name == cmdName {
+			return c.Usage()
+		}
+	}
+
+	return ""
 }
 
 // runHelpCmd shows all available commands.
@@ -252,3 +277,49 @@ func runSaveCmd(ctx context.Context, db *genji.DB, engineName string, dbPath str
 
 	return nil
 }
+
+func runImportCmd(ctx context.Context, db *genji.DB, fileType, path, table string) error {
+	if strings.ToLower(fileType) != "csv" {
+		return errors.New("TYPE should be csv")
+	}
+
+	f, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	tx, err := db.Begin(true)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	r := csv.NewReader(f)
+
+	err = tx.Exec(fmt.Sprintf("CREATE TABLE IF NOT EXISTS %s", table))
+	if err != nil {
+		return err
+	}
+
+	headers, err := r.Read()
+	if err != nil {
+		return err
+	}
+
+	for {
+		columns, err := r.Read()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		err = tx.Exec("INSERT INTO "+table+" VALUES ?", document.NewFromCSV(headers, columns))
+		if err != nil {
+			return err
+		}
+	}
+
+	return tx.Commit()
+}

cmd/genji/shell/shell.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/signal"
 	"path/filepath"
@@ -158,7 +157,7 @@ func Run(ctx context.Context, opts *Options) error {
 
 		err := sh.runPrompt(ctx, promptExecCh)
 		if err != nil && err != errExitCtrlD {
-			fmt.Fprintf(os.Stderr, err.Error())
+			fmt.Fprintln(os.Stderr, err.Error())
 		}
 	}()
 
@@ -446,19 +445,19 @@ func (sh *Shell) runCommand(ctx context.Context, in string) error {
 		return runHelpCmd()
 	case ".tables":
 		if len(cmd) > 1 {
-			return stringutil.Errorf("usage: .tables")
+			return stringutil.Errorf(getUsage(".tables"))
 		}
 
 		return runTablesCmd(sh.db, os.Stdout)
 	case ".exit", "exit":
 		if len(cmd) > 1 {
-			return stringutil.Errorf("usage: .exit")
+			return stringutil.Errorf(getUsage(".exit"))
 		}
 
 		return errExitCommand
 	case ".indexes":
 		if len(cmd) > 2 {
-			return stringutil.Errorf("usage: .indexes [tablename]")
+			return stringutil.Errorf(getUsage(".indexes"))
 		}
 
 		var tableName string
@@ -484,6 +483,12 @@ func (sh *Shell) runCommand(ctx context.Context, in string) error {
 		return runSaveCmd(ctx, sh.db, engine, path)
 	case ".schema":
 		return dbutil.DumpSchema(ctx, sh.db, os.Stdout, cmd[1:]...)
+	case ".import":
+		if len(cmd) != 4 {
+			return stringutil.Errorf(getUsage(".import"))
+		}
+
+		return runImportCmd(ctx, sh.db, cmd[1], cmd[2], cmd[3])
 	default:
 		return displaySuggestions(in)
 	}
@@ -498,26 +503,6 @@ func (sh *Shell) runQuery(ctx context.Context, q string) error {
 	return err
 }
 
-func (sh *Shell) runPipedInput(ctx context.Context) (ran bool, err error) {
-	// Check if there is any input being piped in from the terminal
-	stat, _ := os.Stdin.Stat()
-	m := stat.Mode()
-
-	if (m&os.ModeNamedPipe) == 0 /*cat a.txt| prog*/ && !m.IsRegular() /*prog < a.txt*/ { // No input from terminal
-		return false, nil
-	}
-	data, err := ioutil.ReadAll(os.Stdin)
-	if err != nil {
-		return true, stringutil.Errorf("Unable to read piped input: %w", err)
-	}
-	err = sh.runQuery(ctx, string(data))
-	if err != nil {
-		return true, stringutil.Errorf("Unable to execute provided sql statements: %w", err)
-	}
-
-	return true, nil
-}
-
 func (sh *Shell) changelivePrefix() (string, bool) {
 	return sh.livePrefix, sh.multiLine
 }

document/create.go

@@ -285,6 +285,10 @@ func (s sliceArray) GetByIndex(i int) (Value, error) {
 func NewFromCSV(headers, columns []string) Document {
 	fb := NewFieldBuffer()
 	for i, h := range headers {
+		if i >= len(columns) {
+			break
+		}
+
 		fb.Add(h, NewTextValue(columns[i]))
 	}