forked from go-gorm/gorm
/
preload.go
165 lines (142 loc) · 5.61 KB
/
preload.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
package callbacks
import (
"reflect"
"gorm.io/gorm"
"gorm.io/gorm/clause"
"gorm.io/gorm/schema"
"gorm.io/gorm/utils"
)
func preload(db *gorm.DB, rel *schema.Relationship, conds []interface{}, preloads map[string][]interface{}) {
var (
reflectValue = db.Statement.ReflectValue
tx = db.Session(&gorm.Session{NewDB: true}).Model(nil).Session(&gorm.Session{SkipHooks: db.Statement.SkipHooks})
relForeignKeys []string
relForeignFields []*schema.Field
foreignFields []*schema.Field
foreignValues [][]interface{}
identityMap = map[string][]reflect.Value{}
inlineConds []interface{}
)
db.Statement.Settings.Range(func(k, v interface{}) bool {
tx.Statement.Settings.Store(k, v)
return true
})
if rel.JoinTable != nil {
var (
joinForeignFields = make([]*schema.Field, 0, len(rel.References))
joinRelForeignFields = make([]*schema.Field, 0, len(rel.References))
joinForeignKeys = make([]string, 0, len(rel.References))
)
for _, ref := range rel.References {
if ref.OwnPrimaryKey {
joinForeignKeys = append(joinForeignKeys, ref.ForeignKey.DBName)
joinForeignFields = append(joinForeignFields, ref.ForeignKey)
foreignFields = append(foreignFields, ref.PrimaryKey)
} else if ref.PrimaryValue != "" {
tx = tx.Where(clause.Eq{Column: ref.ForeignKey.DBName, Value: ref.PrimaryValue})
} else {
joinRelForeignFields = append(joinRelForeignFields, ref.ForeignKey)
relForeignKeys = append(relForeignKeys, ref.PrimaryKey.DBName)
relForeignFields = append(relForeignFields, ref.PrimaryKey)
}
}
joinIdentityMap, joinForeignValues := schema.GetIdentityFieldValuesMap(reflectValue, foreignFields)
if len(joinForeignValues) == 0 {
return
}
joinResults := rel.JoinTable.MakeSlice().Elem()
column, values := schema.ToQueryValues(clause.CurrentTable, joinForeignKeys, joinForeignValues)
db.AddError(tx.Where(clause.IN{Column: column, Values: values}).Find(joinResults.Addr().Interface()).Error)
// convert join identity map to relation identity map
fieldValues := make([]interface{}, len(joinForeignFields))
joinFieldValues := make([]interface{}, len(joinRelForeignFields))
for i := 0; i < joinResults.Len(); i++ {
for idx, field := range joinForeignFields {
fieldValues[idx], _ = field.ValueOf(joinResults.Index(i))
}
for idx, field := range joinRelForeignFields {
joinFieldValues[idx], _ = field.ValueOf(joinResults.Index(i))
}
if results, ok := joinIdentityMap[utils.ToStringKey(fieldValues...)]; ok {
joinKey := utils.ToStringKey(joinFieldValues...)
identityMap[joinKey] = append(identityMap[joinKey], results...)
}
}
_, foreignValues = schema.GetIdentityFieldValuesMap(joinResults, joinRelForeignFields)
} else {
for _, ref := range rel.References {
if ref.OwnPrimaryKey {
relForeignKeys = append(relForeignKeys, ref.ForeignKey.DBName)
relForeignFields = append(relForeignFields, ref.ForeignKey)
foreignFields = append(foreignFields, ref.PrimaryKey)
} else if ref.PrimaryValue != "" {
tx = tx.Where(clause.Eq{Column: ref.ForeignKey.DBName, Value: ref.PrimaryValue})
} else {
relForeignKeys = append(relForeignKeys, ref.PrimaryKey.DBName)
relForeignFields = append(relForeignFields, ref.PrimaryKey)
foreignFields = append(foreignFields, ref.ForeignKey)
}
}
identityMap, foreignValues = schema.GetIdentityFieldValuesMap(reflectValue, foreignFields)
if len(foreignValues) == 0 {
return
}
}
// nested preload
for p, pvs := range preloads {
tx = tx.Preload(p, pvs...)
}
reflectResults := rel.FieldSchema.MakeSlice().Elem()
column, values := schema.ToQueryValues(clause.CurrentTable, relForeignKeys, foreignValues)
for _, cond := range conds {
if fc, ok := cond.(func(*gorm.DB) *gorm.DB); ok {
tx = fc(tx)
} else {
inlineConds = append(inlineConds, cond)
}
}
db.AddError(tx.Where(clause.IN{Column: column, Values: values}).Find(reflectResults.Addr().Interface(), inlineConds...).Error)
fieldValues := make([]interface{}, len(relForeignFields))
// clean up old values before preloading
switch reflectValue.Kind() {
case reflect.Struct:
switch rel.Type {
case schema.HasMany, schema.Many2Many:
rel.Field.Set(reflectValue, reflect.MakeSlice(rel.Field.IndirectFieldType, 0, 10).Interface())
default:
rel.Field.Set(reflectValue, reflect.New(rel.Field.FieldType).Interface())
}
case reflect.Slice, reflect.Array:
for i := 0; i < reflectValue.Len(); i++ {
switch rel.Type {
case schema.HasMany, schema.Many2Many:
rel.Field.Set(reflectValue.Index(i), reflect.MakeSlice(rel.Field.IndirectFieldType, 0, 10).Interface())
default:
rel.Field.Set(reflectValue.Index(i), reflect.New(rel.Field.FieldType).Interface())
}
}
}
for i := 0; i < reflectResults.Len(); i++ {
elem := reflectResults.Index(i)
for idx, field := range relForeignFields {
fieldValues[idx], _ = field.ValueOf(elem)
}
for _, data := range identityMap[utils.ToStringKey(fieldValues...)] {
reflectFieldValue := rel.Field.ReflectValueOf(data)
if reflectFieldValue.Kind() == reflect.Ptr && reflectFieldValue.IsNil() {
reflectFieldValue.Set(reflect.New(rel.Field.FieldType.Elem()))
}
reflectFieldValue = reflect.Indirect(reflectFieldValue)
switch reflectFieldValue.Kind() {
case reflect.Struct:
rel.Field.Set(data, reflectResults.Index(i).Interface())
case reflect.Slice, reflect.Array:
if reflectFieldValue.Type().Elem().Kind() == reflect.Ptr {
rel.Field.Set(data, reflect.Append(reflectFieldValue, elem).Interface())
} else {
rel.Field.Set(data, reflect.Append(reflectFieldValue, elem.Elem()).Interface())
}
}
}
}
}