🐛 fix(db): 保留多写语句结果并修复 MySQL 字符集参数

- 多条写语句改为逐条返回 affectedRows，避免只显示最后一条结果

- 为写语句结果补充 statementIndex，保持语句与结果映射

- 保留 MySQL charset fallback 逗号，避免驱动解析成 %2C

internal/app/methods_db_multi_test.go

@@ -10,18 +10,19 @@ import (
 )
 
 type fakeBatchWriteDB struct {
-	batchCalls  int
-	execCalls   int
-	execQueries []string
-	lastQuery   string
-	lastCtx     context.Context
-	queryCalls  int
-	queryMap    map[string][]map[string]interface{}
-	fieldMap    map[string][]string
-	messageMap  map[string][]string
-	multiResult map[string][]connection.ResultSetData
-	queryErr    map[string]error
-	session     *fakeBatchWriteSession
+	batchCalls   int
+	execCalls    int
+	execQueries  []string
+	lastQuery    string
+	lastCtx      context.Context
+	queryCalls   int
+	queryMap     map[string][]map[string]interface{}
+	fieldMap     map[string][]string
+	messageMap   map[string][]string
+	multiResult  map[string][]connection.ResultSetData
+	queryErr     map[string]error
+	execAffected map[string]int64
+	session      *fakeBatchWriteSession
 }
 
 func (f *fakeBatchWriteDB) Connect(config connection.ConnectionConfig) error {
@@ -52,6 +53,9 @@ func (f *fakeBatchWriteDB) QueryWithMessages(query string) ([]map[string]interfa
 func (f *fakeBatchWriteDB) Exec(query string) (int64, error) {
 	f.execCalls++
 	f.execQueries = append(f.execQueries, query)
+	if affected, ok := f.execAffected[query]; ok {
+		return affected, nil
+	}
 	return 1, nil
 }
 
@@ -91,6 +95,9 @@ func (f *fakeBatchWriteDB) ExecContext(ctx context.Context, query string) (int64
 	f.lastCtx = ctx
 	f.execCalls++
 	f.execQueries = append(f.execQueries, query)
+	if affected, ok := f.execAffected[query]; ok {
+		return affected, nil
+	}
 	return 1, nil
 }
 
@@ -440,13 +447,20 @@ func TestDBQueryWithCancel_DuckDBQueriesDoNotInheritConnectTimeout(t *testing.T)
 	}
 }
 
-func TestDBQueryMultiUsesBatchWriteExecerForAllWriteStatements(t *testing.T) {
+func TestDBQueryMultiPreservesPerStatementResultsForMultipleWriteStatements(t *testing.T) {
 	originalNewDatabaseFunc := newDatabaseFunc
 	t.Cleanup(func() {
 		newDatabaseFunc = originalNewDatabaseFunc
 	})
 
-	fakeDB := &fakeBatchWriteDB{}
+	firstStmt := "DELETE FROM assets_asset"
+	secondStmt := "DELETE FROM assets_assetcategory"
+	fakeDB := &fakeBatchWriteDB{
+		execAffected: map[string]int64{
+			firstStmt:  5,
+			secondStmt: 10,
+		},
+	}
 	newDatabaseFunc = func(dbType string) (db.Database, error) {
 		return fakeDB, nil
 	}
@@ -458,31 +472,37 @@ func TestDBQueryMultiUsesBatchWriteExecerForAllWriteStatements(t *testing.T) {
 		Port: 1433,
 		User: "sa",
 	}
-	query := "INSERT INTO demo(id) VALUES (1);\nINSERT INTO demo(id) VALUES (2);"
+	query := firstStmt + ";\n" + secondStmt + ";"
 
 	result := app.DBQueryMulti(config, "testdb", query, "batch-write-test")
 	if !result.Success {
 		t.Fatalf("expected DBQueryMulti success, got failure: %s", result.Message)
 	}
-	if fakeDB.batchCalls != 1 {
-		t.Fatalf("expected batch path to run once, got %d", fakeDB.batchCalls)
+	if fakeDB.batchCalls != 0 {
+		t.Fatalf("expected multiple write statements to skip batch path so each result can be preserved, got %d", fakeDB.batchCalls)
 	}
-	if fakeDB.execCalls != 0 {
-		t.Fatalf("expected sequential exec path to be skipped, got execCalls=%d", fakeDB.execCalls)
+	if fakeDB.execCalls != 2 {
+		t.Fatalf("expected sequential exec path to run twice, got execCalls=%d", fakeDB.execCalls)
 	}
-	if fakeDB.lastQuery != query {
-		t.Fatalf("expected batch query to stay intact, got %q", fakeDB.lastQuery)
+	if len(fakeDB.execQueries) != 2 || fakeDB.execQueries[0] != firstStmt || fakeDB.execQueries[1] != secondStmt {
+		t.Fatalf("expected sequential execs to preserve statement order, got %#v", fakeDB.execQueries)
 	}
 
 	resultSets, ok := result.Data.([]connection.ResultSetData)
 	if !ok {
 		t.Fatalf("expected []connection.ResultSetData, got %T", result.Data)
 	}
-	if len(resultSets) != 1 || len(resultSets[0].Rows) != 1 {
-		t.Fatalf("expected one affectedRows result set, got %#v", resultSets)
+	if len(resultSets) != 2 {
+		t.Fatalf("expected one affectedRows result set per statement, got %#v", resultSets)
 	}
-	if got := resultSets[0].Rows[0]["affectedRows"]; got != int64(500) {
-		t.Fatalf("expected affectedRows=500, got %#v", got)
+	if len(resultSets[0].Rows) != 1 || len(resultSets[1].Rows) != 1 {
+		t.Fatalf("expected both result sets to contain a single affectedRows row, got %#v", resultSets)
+	}
+	if got := resultSets[0].Rows[0]["affectedRows"]; got != int64(5) {
+		t.Fatalf("expected first affectedRows=5, got %#v", got)
+	}
+	if got := resultSets[1].Rows[0]["affectedRows"]; got != int64(10) {
+		t.Fatalf("expected second affectedRows=10, got %#v", got)
 	}
 }