public/tdengine-mapper-go
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feat: 去掉了批量查询时，结果为空的报错

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This commit is contained in:
周杰 2024-09-19 14:11:17 +08:00
parent 1f9ff72824
commit dde9b6f74e
2 changed files with 5 additions and 9 deletions
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4
README.md
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@ -73,6 +73,7 @@ INSERT INTO
### 查询映射 -- 示例 ### 查询映射 -- 示例
```go ```go
// 如果没有结果，会返回 sql.ErrNoRows
func QueryOne(db *sql.DB) (*User,error){ func QueryOne(db *sql.DB) (*User,error){
tdMapper := NewMapper() tdMapper := NewMapper()
@ -89,8 +90,7 @@ func QueryOne(db *sql.DB) (*User,error){
return &user, nil return &user, nil
} }
// 如果查询结果数量为0，则返回 sql.ErrNoRows // 如果查询结果数量为0，不会返回错误
// var ErrNoRows = errors.New("sql: no rows in result set")
func QueryAll(db *sql.DB)([]*User, error) { func QueryAll(db *sql.DB)([]*User, error) {
tdMapper := NewMapper() tdMapper := NewMapper()

10
mapping.go
View File

@ -247,10 +247,6 @@ func (b *Mapper) ScanRowsWithContext(ctx context.Context, target any, rows *sql.
// 将新实例添加到slice中 // 将新实例添加到slice中
vf.Set(reflect.Append(vf, newStruct)) vf.Set(reflect.Append(vf, newStruct))
} }
if vf.Len() == 0 { // 如果slice为空，返回 sql.ErrNoRows
return sql.ErrNoRows
}
return nil return nil
default: default:
return errors.New("target must be a pointer to a struct or a slice of structs") return errors.New("target must be a pointer to a struct or a slice of structs")
@ -277,11 +273,11 @@ func (b *Mapper) scanRow(target reflect.Value, rows *sql.Rows) error {
dest := make([]interface{}, len(columns)) dest := make([]interface{}, len(columns))
for i, colName := range columns { for i, colName := range columns {
// 拿到缓存的字段索引 // 拿到缓存的字段索引
if idx, ok := mate.DBName2IndexCache[colName]; ok { idx, ok := mate.DBName2IndexCache[colName]
dest[i] = target.FieldByIndex(idx).Addr().Interface() if !ok {
} else {
return fmt.Errorf("no corresponding field found for column %s", colName) return fmt.Errorf("no corresponding field found for column %s", colName)
} }
dest[i] = target.FieldByIndex(idx).Addr().Interface()
} }
// 扫描数据 // 扫描数据