Add slice read / writer (noborus#47)

* Add slice read / writer
* Add go slice to import/export.
* Add test and example

README.md

@@ -1,7 +1,7 @@
 # trdsql
 
 [![Build Status](https://travis-ci.org/noborus/trdsql.svg?branch=master)](https://travis-ci.org/noborus/trdsql)
-[![GoDoc](https://godoc.org/github.com/noborus/trdsql?status.svg)](https://https://godoc.org/github.com/noborus/trdsql)
+[![GoDoc](https://godoc.org/github.com/noborus/trdsql?status.svg)](https://godoc.org/github.com/noborus/trdsql)
 
 A tool that can execute SQL queries on [CSV](https://tools.ietf.org/html/rfc4180), [LTSV](http://ltsv.org/), [JSON](https://tools.ietf.org/html/rfc7159) and [TBLN](https://tbln.dev/).
 

_example/simple/main.go

@@ -1,47 +1,18 @@
 package main
 
 import (
-	"fmt"
 	"log"
 
 	"github.com/noborus/trdsql"
 )
 
-type ArrayTable struct {
-	table [][]string
-}
-
-func (a *ArrayTable) PreWrite(columns []string, types []string) error {
-	a.table = make([][]string, 0)
-	fmt.Println(columns, types)
-	return nil
-}
-func (a *ArrayTable) WriteRow(values []interface{}, columns []string) error {
-	row := make([]string, len(values))
-	for i, v := range values {
-		row[i] = trdsql.ValString(v)
-	}
-	a.table = append(a.table, row)
-	return nil
-}
-func (a *ArrayTable) PostWrite() error {
-	return nil
-}
-
-func exec(query string) [][]string {
-	writer := &ArrayTable{}
-	trd := trdsql.NewTRDSQL(trdsql.NewImporter(), trdsql.NewExporter(writer))
-	trd.Driver = "postgres"
-	trd.Dsn = ""
-	err := trd.Exec(query)
+func main() {
+	trd := trdsql.NewTRDSQL(
+		trdsql.NewImporter(trdsql.InDelimiter(":")),
+		trdsql.NewExporter(trdsql.NewWriter()),
+	)
+	err := trd.Exec("SELECT c1 FROM /etc/passwd")
 	if err != nil {
 		log.Fatal(err)
 	}
-	return writer.table
-}
-
-func main() {
-	trdsql.EnableDebug()
-	table := exec("SELECT * FROM test")
-	fmt.Println(table)
 }

_example/slice/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"github.com/noborus/trdsql"
+)
+
+func sliceQuery(slice interface{}, tableName string, query string) ([][]interface{}, error) {
+	// trdsql.EnableDebug()
+	importer := trdsql.NewSliceImporter(tableName, slice)
+	writer := trdsql.NewSliceWriter()
+	trd := trdsql.NewTRDSQL(importer, trdsql.NewExporter(writer))
+	err := trd.Exec(query)
+	return writer.Table, err
+}
+
+func main() {
+	data := []struct {
+		id   int
+		name string
+	}{
+		{id: 1, name: "Bod"},
+		{id: 2, name: "Alice"},
+		{id: 3, name: "Henry"},
+	}
+	table, err := sliceQuery(data, "slice", "SELECT name,id FROM slice ORDER BY id DESC")
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(table)
+	// Output:
+	// [[Henry 3] [Alice 2] [Bod 1]]
+}

example_test.go

@@ -0,0 +1,65 @@
+package trdsql_test
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+
+	"github.com/noborus/trdsql"
+)
+
+func Example() {
+	in := []byte(`"Rob","Pike",rob
+Ken,Thompson,ken
+"Robert","Griesemer","gri"
+`)
+	tmpfile, err := ioutil.TempFile("/tmp", "xxx")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer func() {
+		defer os.Remove(tmpfile.Name())
+	}()
+	_, err = tmpfile.Write(in)
+	if err != nil {
+		log.Fatal(err)
+	}
+	trd := trdsql.NewTRDSQL(
+		trdsql.NewImporter(),
+		trdsql.NewExporter(trdsql.NewWriter()),
+	)
+	query := fmt.Sprintf("SELECT c1 FROM %s ORDER BY c1", tmpfile.Name())
+	err = trd.Exec(query)
+	if err != nil {
+		log.Fatal(err)
+	}
+	// Output:
+	// Ken
+	// Rob
+	// Robert
+}
+
+func ExampleSliceReader() {
+	data := []struct {
+		id   int
+		name string
+	}{
+		{id: 1, name: "Bod"},
+		{id: 2, name: "Alice"},
+		{id: 3, name: "Henry"},
+	}
+	tableName := "slice"
+	importer := trdsql.NewSliceImporter(tableName, data)
+	writer := trdsql.NewSliceWriter()
+	trd := trdsql.NewTRDSQL(importer, trdsql.NewExporter(writer))
+
+	err := trd.Exec("SELECT name,id FROM slice ORDER BY id DESC")
+	if err != nil {
+		log.Fatal(err)
+	}
+	table := writer.Table
+	fmt.Print(table)
+	// Output:
+	// [[Henry 3] [Alice 2] [Bod 1]]
+}

importer.go

@@ -17,23 +17,11 @@ type Importer interface {
 }
 
 // ReadFormat is a structure that includes ReadOpts,
-//  and is an implementation of the Importer interface.
+// and is an implementation of the Importer interface.
 type ReadFormat struct {
 	*ReadOpts
 }
 
-// NewReadOpts Returns ReadOpts.
-func NewReadOpts() *ReadOpts {
-	return &ReadOpts{
-		InFormat:    GUESS,
-		InPreRead:   1,
-		InSkip:      0,
-		InDelimiter: ",",
-		InHeader:    false,
-		IsTemporary: true,
-	}
-}
-
 // NewImporter returns trdsql default Importer.
 func NewImporter(options ...ReadOpt) *ReadFormat {
 	readOpts := NewReadOpts()

importer_slice.go

@@ -0,0 +1,28 @@
+package trdsql
+
+type SliceImporter struct {
+	*SliceReader
+}
+
+func NewSliceImporter(tableName string, data interface{}) *SliceImporter {
+	return &SliceImporter{
+		SliceReader: NewSliceReader(tableName, data),
+	}
+}
+
+func (i *SliceImporter) Import(db *DB, query string) (string, error) {
+	names, err := i.Names()
+	if err != nil {
+		return query, err
+	}
+	types, err := i.Types()
+	if err != nil {
+		return query, err
+	}
+	err = db.CreateTable(i.tableName, names, types, true)
+	if err != nil {
+		return query, err
+	}
+	err = db.Import(i.tableName, names, i.SliceReader)
+	return query, err
+}

importer_test.go

@@ -104,14 +104,14 @@ func Test_sqlFields(t *testing.T) {
 	}
 }
 
-func newDBTestSqlite3(t *testing.T) *DB {
+func newDBTestSqlite3() *DB {
 	db, err := Connect("sqlite3", "")
 	if err != nil {
-		t.Fatal(err)
+		return nil
 	}
 	return db
 }
-func newDBTestPostgres(t *testing.T) *DB {
+func newDBTestPostgres() *DB {
 	db, err := Connect("postgres", "dbname=trdsql_test")
 	if err != nil {
 		return nil
@@ -122,7 +122,7 @@ func newDBTestPostgres(t *testing.T) *DB {
 	}
 	return db
 }
-func newDBTestMysql(t *testing.T) *DB {
+func newDBTestMysql() *DB {
 	db, err := Connect("mysql", "root@/trdsql_test")
 	if err != nil {
 		return nil
@@ -133,7 +133,11 @@ func newDBTestMysql(t *testing.T) *DB {
 	}
 	return db
 }
-
+func csvReadOpts() *ReadOpts {
+	opts := NewReadOpts()
+	opts.InFormat = CSV
+	return opts
+}
 func TestImportFile(t *testing.T) {
 	type args struct {
 		db       *DB
@@ -149,27 +153,17 @@ func TestImportFile(t *testing.T) {
 		{
 			name: "testNoFile",
 			args: args{
-				db:       newDBTestSqlite3(t),
+				db:       newDBTestSqlite3(),
 				fileName: "nofile",
 				opts:     NewReadOpts(),
 			},
 			want:    "",
 			wantErr: false,
 		},
-		{
-			name: "testSqlite",
-			args: args{
-				db:       newDBTestSqlite3(t),
-				fileName: "testdata/test.csv",
-				opts:     NewReadOpts(),
-			},
-			want:    "`testdata/test.csv`",
-			wantErr: false,
-		},
 		{
 			name: "testGlobFile",
 			args: args{
-				db:       newDBTestSqlite3(t),
+				db:       newDBTestSqlite3(),
 				fileName: "testdata/test*.csv",
 				opts:     NewReadOpts(),
 			},
@@ -179,17 +173,37 @@ func TestImportFile(t *testing.T) {
 		{
 			name: "testNoMatch",
 			args: args{
-				db:       newDBTestSqlite3(t),
+				db:       newDBTestSqlite3(),
 				fileName: "testdata/testtttttt*.csv",
 				opts:     NewReadOpts(),
 			},
 			want:    "",
 			wantErr: false,
 		},
+		{
+			name: "testCSV",
+			args: args{
+				db:       newDBTestSqlite3(),
+				fileName: "testdata/test.csv",
+				opts:     csvReadOpts(),
+			},
+			want:    "`testdata/test.csv`",
+			wantErr: false,
+		},
+		{
+			name: "testSqlite",
+			args: args{
+				db:       newDBTestSqlite3(),
+				fileName: "testdata/test.csv",
+				opts:     NewReadOpts(),
+			},
+			want:    "`testdata/test.csv`",
+			wantErr: false,
+		},
 		{
 			name: "testPostgres",
 			args: args{
-				db:       newDBTestPostgres(t),
+				db:       newDBTestPostgres(),
 				fileName: "testdata/test.csv",
 				opts:     NewReadOpts(),
 			},
@@ -199,7 +213,7 @@ func TestImportFile(t *testing.T) {
 		{
 			name: "testMysql",
 			args: args{
-				db:       newDBTestMysql(t),
+				db:       newDBTestMysql(),
 				fileName: "testdata/test.csv",
 				opts:     NewReadOpts(),
 			},