add example/unit testing cases for package gdb

.example/database/gdb/mysql/config.toml

@@ -1,9 +1,13 @@
 
 # MySQL.
 [database]
-	debug   = true
-    link    = "mysql:root:12345678@tcp(127.0.0.1:3306)/test?parseTime=true"
-    MaxOpen = 100
+    [database.logger]
+        Level   = "all"
+        Stdout  = true
+        CtxKeys = ["Trace-Id"]
+    [database.default]
+        link   = "mysql:root:12345678@tcp(127.0.0.1:3306)/test"
+        debug  = true
 
 # Redis.
 [redis]

.example/database/gdb/mysql/gdb_ctx.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"context"
+	"github.com/gogf/gf/frame/g"
+)
+
+func main() {
+	ctx := context.WithValue(context.Background(), "Trace-Id", "123456789")
+	_, err := g.DB().Ctx(ctx).Query("SELECT 1")
+	if err != nil {
+		panic(err)
+	}
+}

.example/database/gdb/mysql/gdb_ctx_model.go

@@ -0,0 +1,14 @@
+package main
+
+import (
+	"context"
+	"github.com/gogf/gf/frame/g"
+)
+
+func main() {
+	ctx := context.WithValue(context.Background(), "Trace-Id", "123456789")
+	_, err := g.DB().Model("user").Ctx(ctx).All()
+	if err != nil {
+		panic(err)
+	}
+}

database/gdb/gdb_z_mysql_method_test.go

@@ -7,9 +7,11 @@
 package gdb_test
 
 import (
+	"context"
 	"fmt"
 	"github.com/gogf/gf/container/garray"
 	"github.com/gogf/gf/encoding/gparser"
+	"github.com/gogf/gf/text/gstr"
 	"testing"
 	"time"
 
@@ -1468,3 +1470,22 @@ func Test_DB_UpdateCounter(t *testing.T) {
 		t.Assert(one["views"].Int(), 0)
 	})
 }
+
+func Test_DB_Ctx(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+		defer cancel()
+		_, err := db.Ctx(ctx).Query("SELECT SLEEP(10)")
+		t.Assert(gstr.Contains(err.Error(), "deadline"), true)
+	})
+}
+
+func Test_DB_Ctx_Logger(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		defer db.SetDebug(db.GetDebug())
+		db.SetDebug(true)
+		ctx := context.WithValue(context.Background(), "Trace-Id", "123456789")
+		_, err := db.Ctx(ctx).Query("SELECT 1")
+		t.Assert(err, nil)
+	})
+}