chore: add sqlutil.PrintRowsToTable (#98)

sqlutil/printrows.go

@@ -0,0 +1,53 @@
+package sqlutil
+
+import (
+	"database/sql"
+	"fmt"
+	"io"
+	"text/tabwriter"
+)
+
+// PrintRowsToTable prints the rows to the output in a table format.
+func PrintRowsToTable(rows *sql.Rows, output io.Writer) error {
+	w := tabwriter.NewWriter(output, 0, 0, 1, ' ', tabwriter.AlignRight|tabwriter.Debug)
+	// Get column names
+	columns, err := rows.Columns()
+	if err != nil {
+		return fmt.Errorf("getting column names: %w", err)
+	}
+
+	for _, column := range columns {
+		fmt.Fprint(w, "\t"+column)
+	}
+	fmt.Fprintln(w, "\t")
+	for range columns {
+		fmt.Fprint(w, "\t---")
+	}
+	fmt.Fprintln(w, "\t")
+
+	values := make([]any, len(columns))
+	scanArgs := make([]any, len(values))
+	for i := range values {
+		scanArgs[i] = &values[i]
+	}
+
+	for rows.Next() {
+		err = rows.Scan(scanArgs...)
+		if err != nil {
+			return fmt.Errorf("scanning row: %w", err)
+		}
+		for _, value := range values {
+			switch value := value.(type) {
+			case nil:
+				fmt.Fprint(w, "\tNULL")
+			case []byte:
+				fmt.Fprint(w, "\t"+string(value))
+			default:
+				fmt.Fprintf(w, "\t%v", value)
+			}
+		}
+		fmt.Fprintln(w, "\t")
+	}
+	w.Flush()
+	return rows.Err()
+}

sqlutil/printrows_test.go

@@ -0,0 +1,46 @@
+package sqlutil_test
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"github.com/ory/dockertest/v3"
+	"github.com/stretchr/testify/require"
+
+	"github.com/rudderlabs/rudder-go-kit/sqlutil"
+	"github.com/rudderlabs/rudder-go-kit/testhelper/docker/resource"
+)
+
+func TestPrintRowsToTable(t *testing.T) {
+	pool, err := dockertest.NewPool("")
+	require.NoError(t, err)
+	postgres, err := resource.SetupPostgres(pool, t)
+	require.NoError(t, err)
+
+	_, err = postgres.DB.Exec(`CREATE TABLE users (
+		id SERIAL PRIMARY KEY,
+		name TEXT NOT NULL,
+		age INT NOT NULL,
+		info JSONB
+		)`)
+	require.NoError(t, err)
+	_, err = postgres.DB.Exec(`INSERT INTO users (name, age, info) VALUES ('John Doe', 20, '{"email": "jdoe@example.com"}')`)
+	require.NoError(t, err)
+	_, err = postgres.DB.Exec(`INSERT INTO users (name, age, info) VALUES ('Eva Chung', 20, '{"email": "echung@example.com"}')`)
+	require.NoError(t, err)
+
+	var out bytes.Buffer
+	rows, err := postgres.DB.Query(`SELECT * FROM users`)
+	require.NoError(t, err)
+	defer func() { _ = rows.Close() }()
+	err = sqlutil.PrintRowsToTable(rows, &out)
+	require.NoError(t, err)
+	fmt.Println(out.String())
+	require.Equal(t,
+		` |  id|      name| age|                            info|
+ | ---|       ---| ---|                             ---|
+ |   1|  John Doe|  20|   {"email": "jdoe@example.com"}|
+ |   2| Eva Chung|  20| {"email": "echung@example.com"}|
+`, out.String())
+}