feat(alerting): add limit and since id options for alert logs

pkg/services/sqlstore/alert_rule_changes.go

@@ -1,6 +1,7 @@
 package sqlstore
 
 import (
+	"bytes"
 	"github.com/go-xorm/xorm"
 	"github.com/grafana/grafana/pkg/bus"
 	m "github.com/grafana/grafana/pkg/models"
@@ -12,8 +13,33 @@ func init() {
 }
 
 func GetAlertRuleChanges(query *m.GetAlertChangesQuery) error {
+	var sql bytes.Buffer
+	params := make([]interface{}, 0)
+
+	sql.WriteString(`SELECT
+					  alert_rule_change.id,
+					  alert_rule_change.org_id,
+					  alert_rule_change.alert_id,
+					  alert_rule_change.type,
+					  alert_rule_change.created
+					  FROM alert_rule_change
+					  `)
+
+	sql.WriteString(`WHERE alert_rule_change.org_id = ?`)
+	params = append(params, query.OrgId)
+
+	if query.SinceId != 0 {
+		sql.WriteString(`AND alert_rule_change.id >= ?`)
+		params = append(params, query.SinceId)
+	}
+
+	if query.Limit != 0 {
+		sql.WriteString(` ORDER BY alert_rule_change.id DESC LIMIT ?`)
+		params = append(params, query.Limit)
+	}
+
 	alertChanges := make([]m.AlertRuleChange, 0)
-	if err := x.Where("org_id = ?", query.OrgId).Find(&alertChanges); err != nil {
+	if err := x.Sql(sql.String(), params...).Find(&alertChanges); err != nil {
 		return err
 	}