gotosocial/vendor/github.com/uptrace/bun/relation_join.go
2021-10-24 13:14:37 +02:00

315 lines
6.7 KiB
Go

package bun
import (
"context"
"reflect"
"github.com/uptrace/bun/internal"
"github.com/uptrace/bun/schema"
)
type relationJoin struct {
Parent *relationJoin
BaseModel TableModel
JoinModel TableModel
Relation *schema.Relation
apply func(*SelectQuery) *SelectQuery
columns []schema.QueryWithArgs
}
func (j *relationJoin) applyTo(q *SelectQuery) {
if j.apply == nil {
return
}
var table *schema.Table
var columns []schema.QueryWithArgs
// Save state.
table, q.table = q.table, j.JoinModel.Table()
columns, q.columns = q.columns, nil
q = j.apply(q)
// Restore state.
q.table = table
j.columns, q.columns = q.columns, columns
}
func (j *relationJoin) Select(ctx context.Context, q *SelectQuery) error {
switch j.Relation.Type {
}
panic("not reached")
}
func (j *relationJoin) selectMany(ctx context.Context, q *SelectQuery) error {
q = j.manyQuery(q)
if q == nil {
return nil
}
return q.Scan(ctx)
}
func (j *relationJoin) manyQuery(q *SelectQuery) *SelectQuery {
hasManyModel := newHasManyModel(j)
if hasManyModel == nil {
return nil
}
q = q.Model(hasManyModel)
var where []byte
if len(j.Relation.JoinFields) > 1 {
where = append(where, '(')
}
where = appendColumns(where, j.JoinModel.Table().SQLAlias, j.Relation.JoinFields)
if len(j.Relation.JoinFields) > 1 {
where = append(where, ')')
}
where = append(where, " IN ("...)
where = appendChildValues(
q.db.Formatter(),
where,
j.JoinModel.rootValue(),
j.JoinModel.parentIndex(),
j.Relation.BaseFields,
)
where = append(where, ")"...)
q = q.Where(internal.String(where))
if j.Relation.PolymorphicField != nil {
q = q.Where("? = ?", j.Relation.PolymorphicField.SQLName, j.Relation.PolymorphicValue)
}
j.applyTo(q)
q = q.Apply(j.hasManyColumns)
return q
}
func (j *relationJoin) hasManyColumns(q *SelectQuery) *SelectQuery {
b := make([]byte, 0, 32)
joinTable := j.JoinModel.Table()
if len(j.columns) > 0 {
for i, col := range j.columns {
if i > 0 {
b = append(b, ", "...)
}
if col.Args == nil {
if field, ok := joinTable.FieldMap[col.Query]; ok {
b = append(b, joinTable.SQLAlias...)
b = append(b, '.')
b = append(b, field.SQLName...)
continue
}
}
var err error
b, err = col.AppendQuery(q.db.fmter, b)
if err != nil {
q.setErr(err)
return q
}
}
} else {
b = appendColumns(b, joinTable.SQLAlias, joinTable.Fields)
}
q = q.ColumnExpr(internal.String(b))
return q
}
func (j *relationJoin) selectM2M(ctx context.Context, q *SelectQuery) error {
q = j.m2mQuery(q)
if q == nil {
return nil
}
return q.Scan(ctx)
}
func (j *relationJoin) m2mQuery(q *SelectQuery) *SelectQuery {
fmter := q.db.fmter
m2mModel := newM2MModel(j)
if m2mModel == nil {
return nil
}
q = q.Model(m2mModel)
index := j.JoinModel.parentIndex()
baseTable := j.BaseModel.Table()
if j.Relation.M2MTable != nil {
q = q.ColumnExpr(string(j.Relation.M2MTable.SQLAlias) + ".*")
}
//nolint
var join []byte
join = append(join, "JOIN "...)
join = fmter.AppendQuery(join, string(j.Relation.M2MTable.Name))
join = append(join, " AS "...)
join = append(join, j.Relation.M2MTable.SQLAlias...)
join = append(join, " ON ("...)
for i, col := range j.Relation.M2MBaseFields {
if i > 0 {
join = append(join, ", "...)
}
join = append(join, j.Relation.M2MTable.SQLAlias...)
join = append(join, '.')
join = append(join, col.SQLName...)
}
join = append(join, ") IN ("...)
join = appendChildValues(fmter, join, j.BaseModel.rootValue(), index, baseTable.PKs)
join = append(join, ")"...)
q = q.Join(internal.String(join))
joinTable := j.JoinModel.Table()
for i, m2mJoinField := range j.Relation.M2MJoinFields {
joinField := j.Relation.JoinFields[i]
q = q.Where("?.? = ?.?",
joinTable.SQLAlias, joinField.SQLName,
j.Relation.M2MTable.SQLAlias, m2mJoinField.SQLName)
}
j.applyTo(q)
q = q.Apply(j.hasManyColumns)
return q
}
func (j *relationJoin) hasParent() bool {
if j.Parent != nil {
switch j.Parent.Relation.Type {
case schema.HasOneRelation, schema.BelongsToRelation:
return true
}
}
return false
}
func (j *relationJoin) appendAlias(fmter schema.Formatter, b []byte) []byte {
quote := fmter.IdentQuote()
b = append(b, quote)
b = appendAlias(b, j)
b = append(b, quote)
return b
}
func (j *relationJoin) appendAliasColumn(fmter schema.Formatter, b []byte, column string) []byte {
quote := fmter.IdentQuote()
b = append(b, quote)
b = appendAlias(b, j)
b = append(b, "__"...)
b = append(b, column...)
b = append(b, quote)
return b
}
func (j *relationJoin) appendBaseAlias(fmter schema.Formatter, b []byte) []byte {
quote := fmter.IdentQuote()
if j.hasParent() {
b = append(b, quote)
b = appendAlias(b, j.Parent)
b = append(b, quote)
return b
}
return append(b, j.BaseModel.Table().SQLAlias...)
}
func (j *relationJoin) appendSoftDelete(b []byte, flags internal.Flag) []byte {
b = append(b, '.')
b = append(b, j.JoinModel.Table().SoftDeleteField.SQLName...)
if flags.Has(deletedFlag) {
b = append(b, " IS NOT NULL"...)
} else {
b = append(b, " IS NULL"...)
}
return b
}
func appendAlias(b []byte, j *relationJoin) []byte {
if j.hasParent() {
b = appendAlias(b, j.Parent)
b = append(b, "__"...)
}
b = append(b, j.Relation.Field.Name...)
return b
}
func (j *relationJoin) appendHasOneJoin(
fmter schema.Formatter, b []byte, q *SelectQuery,
) (_ []byte, err error) {
isSoftDelete := j.JoinModel.Table().SoftDeleteField != nil && !q.flags.Has(allWithDeletedFlag)
b = append(b, "LEFT JOIN "...)
b = fmter.AppendQuery(b, string(j.JoinModel.Table().SQLNameForSelects))
b = append(b, " AS "...)
b = j.appendAlias(fmter, b)
b = append(b, " ON "...)
b = append(b, '(')
for i, baseField := range j.Relation.BaseFields {
if i > 0 {
b = append(b, " AND "...)
}
b = j.appendAlias(fmter, b)
b = append(b, '.')
b = append(b, j.Relation.JoinFields[i].SQLName...)
b = append(b, " = "...)
b = j.appendBaseAlias(fmter, b)
b = append(b, '.')
b = append(b, baseField.SQLName...)
}
b = append(b, ')')
if isSoftDelete {
b = append(b, " AND "...)
b = j.appendAlias(fmter, b)
b = j.appendSoftDelete(b, q.flags)
}
return b, nil
}
func appendChildValues(
fmter schema.Formatter, b []byte, v reflect.Value, index []int, fields []*schema.Field,
) []byte {
seen := make(map[string]struct{})
walk(v, index, func(v reflect.Value) {
start := len(b)
if len(fields) > 1 {
b = append(b, '(')
}
for i, f := range fields {
if i > 0 {
b = append(b, ", "...)
}
b = f.AppendValue(fmter, b, v)
}
if len(fields) > 1 {
b = append(b, ')')
}
b = append(b, ", "...)
if _, ok := seen[string(b[start:])]; ok {
b = b[:start]
} else {
seen[string(b[start:])] = struct{}{}
}
})
if len(seen) > 0 {
b = b[:len(b)-2] // trim ", "
}
return b
}