Documentation
¶
Overview ¶
Package record holds the record.Record type, which is the core type for holding query results.
Index ¶
- func Equal(a, b Record) bool
- func SetKindIfUnknown(meta Meta, i int, k kind.Kind)
- func Valid(rec Record) (i int, err error)
- type ColumnTypeData
- type FieldMeta
- func (fm *FieldMeta) DatabaseTypeName() string
- func (fm *FieldMeta) DecimalSize() (precision, scale int64, ok bool)
- func (fm *FieldMeta) Kind() kind.Kind
- func (fm *FieldMeta) Length() (length int64, ok bool)
- func (fm *FieldMeta) MungedName() string
- func (fm *FieldMeta) Name() string
- func (fm *FieldMeta) Nullable() (nullable, ok bool)
- func (fm *FieldMeta) ScanType() reflect.Type
- func (fm *FieldMeta) String() string
- type Meta
- type Record
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func SetKindIfUnknown ¶
SetKindIfUnknown sets meta[i].kind to k, iff the kind is currently kind.Unknown or kind.Null. This function can be used to set the kind after-the-fact, which is useful for some databases that don't always return sufficient type info upfront.
func Valid ¶
Valid checks that each element of the record vals is of an acceptable type. On the first unacceptable element, the index of that element and an error are returned. On success (-1, nil) is returned.
These acceptable types, per the stdlib sql pkg, are:
nil, int64, float64, bool, string, []byte, time.Time
Types ¶
type ColumnTypeData ¶
type ColumnTypeData struct {
Name string `json:"name"`
HasNullable bool `json:"has_nullable"`
HasLength bool `json:"has_length"`
HasPrecisionScale bool `json:"has_precision_scale"`
Nullable bool `json:"nullable"`
Length int64 `json:"length"`
DatabaseTypeName string `json:"database_type_name"`
Precision int64 `json:"precision"`
Scale int64 `json:"scale"`
ScanType reflect.Type `json:"scan_type"`
Kind kind.Kind `json:"kind"`
}
ColumnTypeData contains the same data as sql.ColumnType as well SQ's derived data kind. This type exists with exported fields instead of methods (as on sql.ColumnType) due to the need to work with the fields for testing, and also because for some drivers it's useful to twiddle with the scan type.
This is all a bit ugly.
func NewColumnTypeData ¶
func NewColumnTypeData(col *sql.ColumnType, knd kind.Kind) *ColumnTypeData
NewColumnTypeData returns a new instance with field values taken from col, supplemented with the kind param.
type FieldMeta ¶
type FieldMeta struct {
// contains filtered or unexported fields
}
FieldMeta is a bit of a strange entity, and in an ideal world, it wouldn't exist. It's here because:
- The DB driver impls that sq utilizes (postgres, sqlite, etc) often have individual quirks (not reporting nullability etc) that necessitate modifying sql.ColumnType so that there's consistent behavior across the drivers.
- We wanted to retain (and supplement) the method set of sql.ColumnType (basically, use the same "interface", even though sql.ColumnType is a struct, not interface) so that devs don't need to learn a whole new thing.
- For that reason, stdlib sql.ColumnType needs to be supplemented with kind.Kind, and there needs to be a mechanism for modifying sql.ColumnType's fields.
- But sql.ColumnType is sealed (its fields cannot be changed from outside its package).
- Hence this construct where we have FieldMeta (which abstractly is an adapter around sql.ColumnType) and also a data holder struct (ColumnDataType), which permits the mutation of the column type fields.
Likely there's a better design available than this one, but it suffices.
func NewFieldMeta ¶
func NewFieldMeta(data *ColumnTypeData, mungedName string) *FieldMeta
NewFieldMeta returns a new instance backed by the data arg. If mungedName is empty, ColumnTypeData.Name is used.
func (*FieldMeta) DatabaseTypeName ¶
DatabaseTypeName is documented by sql.ColumnType.DatabaseTypeName.
func (*FieldMeta) DecimalSize ¶
DecimalSize is documented by sql.ColumnType.DecimalSize.
func (*FieldMeta) MungedName ¶ added in v0.41.0
MungedName returns the (possibly-munged) column name. This value is what should be used for outputting the col name. This exists largely to handle the case of duplicate col names in a result set, e.g. when doing a JOIN on tables with identically-named columns. But typically this value is the same as that returned by FieldMeta.Name.
type Meta ¶
type Meta []*FieldMeta
Meta is a slice of *FieldMeta, encapsulating the metadata for a record.
func (Meta) MungedNames ¶ added in v0.41.0
MungedNames returns the munged column names, which may be the same as those returned from Meta.Names.
func (Meta) Names ¶
Names returns the column names. These are the col names from the database. See also: MungedNames.
func (Meta) NewScanRow ¶
NewScanRow returns a new []any that can be scanned into by sql.Rows.Scan.
type Record ¶
type Record []any
Record is a []any row of field values returned from a query.
In the codebase, we distinguish between a "Record" and a "ScanRow", although both are []any and are closely related.
An instance of ScanRow is passed to the sql rows.Scan method, and its elements may include implementations of the sql.Scanner interface such as sql.NullString, sql.NullInt64 or even driver-specific types.
A Record is typically built from a ScanRow, unwrapping and munging elements such that the Record only contains standard types:
nil, int64, float64, bool, string, []byte, time.Time
It is an error for a Record to contain elements of any other type.
func CloneSlice ¶ added in v0.37.0
CloneSlice returns a deep copy of recs.
Source Files