diff --git a/database/sampling.go b/database/sampling.go
index 5ccbf55e92d43df2e9dc6f03036b54328c9b0bc2..5d97142515a9c5953e5600ba5d20375f9c5e4008 100644
--- a/database/sampling.go
+++ b/database/sampling.go
@@ -17,12 +17,10 @@
 package database
 
 import (
+	"database/sql"
 	"fmt"
-	"time"
-
 	"strings"
-
-	"database/sql"
+	"time"
 
 	"github.com/XiaoMi/soar/common"
 	"github.com/ziutek/mymysql/mysql"
@@ -92,7 +90,6 @@ func (db *Connector) SamplingData(onlineConn *Connector, database string, tables
 		} else {
 			where = common.Config.SamplingCondition
 		}
-
 		err = db.startSampling(onlineConn.Conn, database, table, where)
 	}
 	return err
@@ -143,17 +140,17 @@ func (db *Connector) startSampling(onlineConn *sql.DB, database, table string, w
 					values = append(values, fmt.Sprintf(`unhex("%s")`, fmt.Sprintf("%x", val)))
 				}
 			}
-		}
-		valuesStr = append(valuesStr, "("+strings.Join(values, `,`)+")")
-		valuesCount++
-		if maxValuesCount <= valuesCount {
-			err = db.doSampling(table, columnsStr, strings.Join(valuesStr, `,`))
-			if err != nil {
-				break
+			valuesStr = append(valuesStr, "("+strings.Join(values, `,`)+")")
+			valuesCount++
+			if maxValuesCount <= valuesCount {
+				err = db.doSampling(table, columnsStr, strings.Join(valuesStr, `,`))
+				if err != nil {
+					break
+				}
+				values = make([]string, 0)
+				valuesStr = make([]string, 0)
+				valuesCount = 0
 			}
-			values = make([]string, 0)
-			valuesStr = make([]string, 0)
-			valuesCount = 0
 		}
 	}
 	res.Close()
diff --git a/env/env_test.go b/env/env_test.go
index fa3805a252ef4714ad5ffc4121fa4b4e4c8b9d67..a1da45f408ee5a423f3754f63e54ea7ed7476268 100644
--- a/env/env_test.go
+++ b/env/env_test.go
@@ -282,3 +282,60 @@ func TestCreateDatabase(t *testing.T) {
 	}
 	common.Log.Debug("Exiting function: %s", common.GetFunctionName())
 }
+
+func TestCreateTable(t *testing.T) {
+	orgSamplingCondition := common.Config.SamplingCondition
+	common.Config.SamplingCondition = "LIMIT 1"
+
+	vEnv, rEnv := BuildEnv()
+	defer vEnv.CleanUp()
+	// TODO: support VIEW,
+	tables := []string{
+		"actor",
+		// "actor_info", // VIEW
+		"address",
+		"category",
+		"city",
+		"country",
+		"customer",
+		"customer_list",
+		"film",
+		"film_actor",
+		"film_category",
+		"film_list",
+		"film_text",
+		"inventory",
+		"language",
+		"nicer_but_slower_film_list",
+		"payment",
+		"rental",
+		// "sales_by_film_category", // VIEW
+		// "sales_by_store", // VIEW
+		"staff",
+		"staff_list",
+		"store",
+	}
+	for _, table := range tables {
+		err := vEnv.createTable(rEnv, "sakila", table)
+		if err != nil {
+			t.Error(err)
+		}
+	}
+	common.Config.SamplingCondition = orgSamplingCondition
+}
+
+func TestCreateDatabase(t *testing.T) {
+	vEnv, rEnv := BuildEnv()
+	defer vEnv.CleanUp()
+	err := vEnv.createDatabase(rEnv, "sakila")
+	if err != nil {
+		t.Error(err)
+	}
+	if vEnv.DBHash("sakila") == "sakila" {
+		t.Errorf("database: sakila rehashed failed!")
+	}
+
+	if vEnv.DBHash("not_exist_db") != "not_exist_db" {
+		t.Errorf("database: not_exist_db rehashed!")
+	}
+}