1. delete database/sql changelog file.

2. delete database/sql config addr param.
3. add stat/metric business metric help.

pkg/database/sql/CHANGELOG.md

@@ -1,24 +0,0 @@
-### database/sql
-
-##### Version 1.3.1
-> 1. trace、metric 区别不同数据库实例（主、从）
-
-##### Version 1.3.0
-> 1. add slow log
-
-##### Version 1.2.1
-> 1.支持上报熔断错误 
-
-##### Version 1.2.0
-> 1.添加数据库读写分离 
-
-##### Version 1.1.1
-> 1.修复部分函数中的context cancel leak  
-
-##### Version 1.1.0
-> 1.添加context和timeout支持  
-> 2.添加breaker支持  
-> 3.更新driver，支持context/pool timeout  
-
-##### Version 1.0.0
-> 1.支持trace/stats  

pkg/database/sql/mysql.go

@@ -11,7 +11,6 @@ import (
 
 // Config mysql config.
 type Config struct {
-	Addr         string          // for trace
 	DSN          string          // write data source name.
 	ReadDSN      []string        // read data source name.
 	Active       int             // pool

pkg/stat/metric/metric.go

@@ -1,6 +1,9 @@
 package metric
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+)
 
 // Opts contains the common arguments for creating Metric.
 type Opts struct {
@@ -62,6 +65,7 @@ func NewBusinessMetricCount(name string, labels ...string) CounterVec {
 		Subsystem: _businessSubsystemCount,
 		Name:      name,
 		Labels:    labels,
+		Help:      fmt.Sprintf("business metric count %s", name),
 	})
 }
 
@@ -76,6 +80,7 @@ func NewBusinessMetricGauge(name string, labels ...string) GaugeVec {
 		Subsystem: _businessSubSystemGauge,
 		Name:      name,
 		Labels:    labels,
+		Help:      fmt.Sprintf("business metric gauge %s", name),
 	})
 }
 
@@ -94,5 +99,6 @@ func NewBusinessMetricHistogram(name string, buckets []float64, labels ...string
 		Name:      name,
 		Labels:    labels,
 		Buckets:   buckets,
+		Help:      fmt.Sprintf("business metric histogram %s", name),
 	})
 }