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uptrace
Scan Map for struct panic ch: column has empty name [recovered]
I have tag all the field with ch:column_name tag , but where db.NewSelect().Model(&result).Limit(1).Scan(ctx) scan the struct panic:ch: column has empty name [recovered]
Please provide https://stackoverflow.com/help/minimal-reproducible-example. The query that panics should be enough.
sorry , now faced a new problem: I have a table like:
CREATE TABLE test.testTable
(
`c1` Date,
`c2` String,
`c3` String,
`c4` String,
`c5` String,
`c6` String,
`c7` String,
`c8` String,
`c9` String,
`c10` String,
`c11` String,
`c12` String,
`c13` String,
`c14` String,
`c15` String,
`c16` Float64,
`c17` Int64,
`c18` Array(Nullable(Int64)),
`c19` Array(Nullable(Int64)),
`c20` Array(Nullable(Int64)),
`c21` Array(Nullable(Int64)),
`c22` String,
`c23` String,
`c24` String
)engine = MergeTree PARTITION BY c1
ORDER BY (c2, c3, c4, c5, c6, c7, c8, c9,
c10, c11, c12, c13, c14, c15, c16, cityHash64(c9))
SAMPLE BY cityHash64(c9)
SETTINGS index_granularity = 8192;
and I my test code is
type testTable struct {
ch.CHModel `ch:"table:testTable,columnar"`
c1 time.Time `ch:"c1"`
c2 string `ch:"c2"`
c3 string `ch:"c3"`
c4 string `ch:"c4"`
c5 string `ch:"c5"`
c6 string `ch:"c6"`
c7 string `ch:"c7"`
c8 string `ch:"c8"`
c9 string `ch:"c9"`
c10 string `ch:"c10"`
c11 string `ch:"c11"`
c12 string `ch:"c12"`
c13 string `ch:"c13"`
c14 string `ch:"c14"`
c15 string `ch:"c15"`
c16 float64 `ch:"c16"`
c17 int64 `ch:"c17"`
c18 []*int64 `ch:"c18"`
c19 []*int64 `ch:"c19"`
c20 []*int64 `ch:"c20"`
c21 []*int64 `ch:"c21"`
c22 string `ch:"c22"`
c23 string `ch:"c23"`
c24 string `ch:"c24"`
}
func TestName(t *testing.T) {
//some init
config.InitLog()
dal.InitGoClickhouseConnection()
conn := dal.GetGoClickhouseConnection()
ctx := context.Background()
dest := new(testTable)
if err := conn.NewSelect().Model(dest).Limit(1).Scan(ctx); err != nil {
panic(err)
}
}
but when I run the code I got this panic message like:
it seems that column tag is not work
Change c1 time.Time ch:"c1" to `C1 time.Time `ch:"c1". Unexported fields are ignored.
Sorry My misstake ,I have changed the c to C ,then I run it again,got this panic:
panic trace :
/Users/wangcong/go/go1.18/src/runtime/panic.go:844 +0x25a
reflect.(*rtype).Elem(0x1a38d60)
/Users/wangcong/go/go1.18/src/reflect/type.go:965 +0x2ae
github.com/uptrace/go-clickhouse/ch/chschema.(*Table).addFields(0xc0001e8380, {0x1cf0350, 0x1b06200}, {0x0, 0x0, 0x0})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/chschema/table.go:150 +0x8e3
github.com/uptrace/go-clickhouse/ch/chschema.(*Table).initFields(0xc0001e8380)
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/chschema/table.go:103 +0x125
github.com/uptrace/go-clickhouse/ch/chschema.newTable({0x1cf0350, 0x1b06200})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/chschema/table.go:61 +0x185
github.com/uptrace/go-clickhouse/ch/chschema.(*tablesMap).Get(0xc0001bb9b0, {0x1cf0350, 0x1b06200})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/chschema/tables.go:32 +0x177
github.com/uptrace/go-clickhouse/ch/chschema.TableForType({0x1cf0350, 0x1b06200})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/chschema/tables.go:12 +0x3d
github.com/uptrace/go-clickhouse/ch.newStructTableModelValue(0xc0000206e0, {0x1b06200, 0xc000583040, 0x199})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/model_table_struct.go:28 +0x58
github.com/uptrace/go-clickhouse/ch.newTableModel(0xc0000206e0, {0x1a212c0, 0xc000583040})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/model.go:109 +0x4fa
github.com/uptrace/go-clickhouse/ch.(*baseQuery).setTableModel(0xc0005831e0, {0x1a212c0, 0xc000583040})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/query_base.go:81 +0x5d
github.com/uptrace/go-clickhouse/ch.(*SelectQuery).Model(0xc0005831e0, {0x1a212c0, 0xc000583040})
/Users/wangcong/go/pkg/mod/github.com/uptrace/[email protected]/ch/query_select.go:46 +0x47
then I changed the struct definition like :
type testTable struct {
ch.CHModel `ch:"table:testTable,columnar"`
C1 *time.Time `ch:"c1,type:Date"`
C2 *string `ch:"c2,type:String"`
C3 *string `ch:"c3,type:String"`
C4 *string `ch:"c4,type:String"`
C5 *string `ch:"c5,type:String"`
C6 *string `ch:"c6,type:String"`
C7 *string `ch:"c7,type:String"`
C8 *string `ch:"c8,type:String"`
C9 *string `ch:"c9,type:String"`
C10 *string `ch:"c10,type:String"`
C11 *string `ch:"c11,type:String"`
C12 *string `ch:"c12,type:String"`
C13 *string `ch:"c13,type:String"`
C14 *string `ch:"c14,type:String"`
C15 *string `ch:"c15,type:String"`
C16 *float64 `ch:"c16,type:Float64"`
C17 *int64 `ch:"c17,type:Int64"`
C18 []*int64 `ch:"c18,type:Array(Nullable(Int64))"`
C19 []*int64 `ch:"c19,type:Array(Nullable(Int64))"`
C20 []*int64 `ch:"c20,type:Array(Nullable(Int64))"`
C21 []*int64 `ch:"c21,type:Array(Nullable(Int64))"`
C22 *string `ch:"c22,type:String"`
C23 *string `ch:"c23,type:String"`
C24 *string `ch:"c24,type:String"`
}
and I run this code :
func TestName(t *testing.T) {
config.InitLog()
dal.InitGoClickhouseConnection()
conn := dal.GetGoClickhouseConnection()
ctx := context.Background()
//dest := new(testTable)
var dest testTable
if err := conn.NewSelect().Model(&dest).Where("c1=?", "2022-06-14").Limit(1).Scan(ctx); err != nil {
panic(err)
}
fmt.Println(dest)
}
It works ,there is no panic ,but I got nothing from the db
but there is a lot rows data in the db:
and when I try run the code like :
func TestName(t *testing.T) {
config.InitLog()
dal.InitGoClickhouseConnection()
conn := dal.GetGoClickhouseConnection()
ctx := context.Background()
//dest := new(testTable)
var dest []testTable
if err := conn.NewSelect().Model(&dest).Where("c1=?", "2022-06-14").Limit(10).Scan(ctx); err != nil {
panic(err)
}
fmt.Println(dest)
}
to try to scan a array of testTable data,the panic ch: column has empty name [recovered],show it again.