diff --git a/sqlite3_test/sqltest.go b/sqlite3_test/sqltest.go
index e73e4ea..0ad9c3a 100644
--- a/sqlite3_test/sqltest.go
+++ b/sqlite3_test/sqltest.go
@@ -11,14 +11,17 @@ import (
 	"time"
 )
 
+// Dialect is a type of dialect of databases.
 type Dialect int
 
+// Dialects for databases.
 const (
-	SQLITE Dialect = iota
-	POSTGRESQL
-	MYSQL
+	SQLITE     Dialect = iota // SQLITE mean SQLite3 dialect
+	POSTGRESQL                // POSTGRESQL mean PostgreSQL dialect
+	MYSQL                     // MYSQL mean MySQL dialect
 )
 
+// DB provide context for the tests
 type DB struct {
 	*testing.T
 	*sql.DB
@@ -149,6 +152,7 @@ func makeBench() {
 	}
 }
 
+// TestResult is test for result
 func TestResult(t *testing.T) {
 	db.tearDown()
 	db.mustExec("create temporary table test (id " + db.serialPK() + ", name varchar(10))")
@@ -175,6 +179,7 @@ func TestResult(t *testing.T) {
 	}
 }
 
+// TestBlobs is test for blobs
 func TestBlobs(t *testing.T) {
 	db.tearDown()
 	var blob = []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
@@ -201,6 +206,7 @@ func TestBlobs(t *testing.T) {
 	}
 }
 
+// TestManyQueryRow is test for many query row
 func TestManyQueryRow(t *testing.T) {
 	if testing.Short() {
 		t.Log("skipping in short mode")
@@ -218,6 +224,7 @@ func TestManyQueryRow(t *testing.T) {
 	}
 }
 
+// TestTxQuery is test for transactional query
 func TestTxQuery(t *testing.T) {
 	db.tearDown()
 	tx, err := db.Begin()
@@ -256,6 +263,7 @@ func TestTxQuery(t *testing.T) {
 	}
 }
 
+// TestPreparedStmt is test for prepared statement
 func TestPreparedStmt(t *testing.T) {
 	db.tearDown()
 	db.mustExec("CREATE TABLE t (count INT)")
@@ -301,6 +309,7 @@ func TestPreparedStmt(t *testing.T) {
 // test -bench but calling Benchmark() from a benchmark test
 // currently hangs go.
 
+// BenchmarkExec is benchmark for exec
 func BenchmarkExec(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		if _, err := db.Exec("select 1"); err != nil {
@@ -309,6 +318,7 @@ func BenchmarkExec(b *testing.B) {
 	}
 }
 
+// BenchmarkQuery is benchmark for query
 func BenchmarkQuery(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		var n sql.NullString
@@ -322,6 +332,7 @@ func BenchmarkQuery(b *testing.B) {
 	}
 }
 
+// BenchmarkParams is benchmark for params
 func BenchmarkParams(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		var n sql.NullString
@@ -335,6 +346,7 @@ func BenchmarkParams(b *testing.B) {
 	}
 }
 
+// BenchmarkStmt is benchmark for statement
 func BenchmarkStmt(b *testing.B) {
 	st, err := db.Prepare("select ?, ?, ?, ?")
 	if err != nil {
@@ -354,6 +366,7 @@ func BenchmarkStmt(b *testing.B) {
 	}
 }
 
+// BenchmarkRows is benchmark for rows
 func BenchmarkRows(b *testing.B) {
 	db.once.Do(makeBench)
 
@@ -378,6 +391,7 @@ func BenchmarkRows(b *testing.B) {
 	}
 }
 
+// BenchmarkStmtRows is benchmark for statement rows
 func BenchmarkStmtRows(b *testing.B) {
 	db.once.Do(makeBench)