Add clause, DB API, model definition

This commit is contained in:
Jinzhu 2020-01-29 19:22:44 +08:00
parent 8eae7e4ab9
commit b9cce2be6a
11 changed files with 769 additions and 1 deletions

2
.gitignore vendored
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TODO TODO*
documents documents
coverage.txt coverage.txt
_book _book

5
association.go Normal file
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package gorm
// Association Mode contains some helper methods to handle relationship things easily.
type Association struct {
}

138
chainable_api.go Normal file
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package gorm
// Model specify the model you would like to run db operations
// // update all users's name to `hello`
// db.Model(&User{}).Update("name", "hello")
// // if user's primary key is non-blank, will use it as condition, then will only update the user's name to `hello`
// db.Model(&user).Update("name", "hello")
func (db *DB) Model(value interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Table specify the table you would like to run db operations
func (db *DB) Table(name string) (tx *DB) {
tx = db.getInstance()
return
}
// Select specify fields that you want when querying, creating, updating
func (db *DB) Select(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Omit specify fields that you want to ignore when creating, updating and querying
func (db *DB) Omit(columns ...string) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Where(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Not add NOT condition
func (db *DB) Not(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Or add OR conditions
func (db *DB) Or(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Joins specify Joins conditions
// db.Joins("JOIN emails ON emails.user_id = users.id AND emails.email = ?", "jinzhu@example.org").Find(&user)
func (db *DB) Joins(query string, args ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Group specify the group method on the find
func (db *DB) Group(column string) (tx *DB) {
tx = db.getInstance()
return
}
// Having specify HAVING conditions for GROUP BY
func (db *DB) Having(query interface{}, args ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Order specify order when retrieve records from database
// db.Order("name DESC")
// db.Order(gorm.Expr("name = ? DESC", "first")) // sql expression
func (db *DB) Order(value interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Limit specify the number of records to be retrieved
func (db *DB) Limit(limit int64) (tx *DB) {
tx = db.getInstance()
return
}
// Offset specify the number of records to skip before starting to return the records
func (db *DB) Offset(offset int64) (tx *DB) {
tx = db.getInstance()
return
}
// Scopes pass current database connection to arguments `func(*DB) *DB`, which could be used to add conditions dynamically
// func AmountGreaterThan1000(db *gorm.DB) *gorm.DB {
// return db.Where("amount > ?", 1000)
// }
//
// func OrderStatus(status []string) func (db *gorm.DB) *gorm.DB {
// return func (db *gorm.DB) *gorm.DB {
// return db.Scopes(AmountGreaterThan1000).Where("status in (?)", status)
// }
// }
//
// db.Scopes(AmountGreaterThan1000, OrderStatus([]string{"paid", "shipped"})).Find(&orders)
// Refer https://jinzhu.github.io/gorm/crud.html#scopes
func (db *DB) Scopes(funcs ...func(*DB) *DB) (tx *DB) {
for _, f := range funcs {
db = f(db)
}
return db
}
//Preloads only preloads relations, don`t touch out
func (db *DB) Preloads(out interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Preload preload associations with given conditions
// db.Preload("Orders", "state NOT IN (?)", "cancelled").Find(&users)
func (db *DB) Preload(column string, conditions ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Assign(attrs ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Attrs(attrs ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Unscoped() (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Raw(sql string, values ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}

53
clause/clause.go Normal file
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package clause
// Builder builder interface
type BuilderInterface interface {
Write(sql ...string) error
WriteQuoted(field interface{}) error
AddVar(vars ...interface{}) string
Quote(field interface{}) string
}
// Interface clause interface
type Interface interface {
Name() string
Build(builder BuilderInterface)
}
// NegationBuilder negation condition builder
type NegationBuilder interface {
NegationBuild(builder BuilderInterface)
}
// Where where clause
type Where struct {
}
// Select select attrs when querying, updating, creating
type Select struct {
Omit bool
}
// Join join clause
type Join struct {
}
// GroupBy group by clause
type GroupBy struct {
}
// Having having clause
type Having struct {
}
// Order order clause
type Order struct {
}
// Limit limit clause
type Limit struct {
}
// Offset offset clause
type Offset struct {
}

19
clause/expr.go Normal file
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package clause
type ExprInterface interface {
}
type Expr struct {
}
type Average struct {
}
type Minimum struct {
}
type Maximum struct {
}
type Sum struct {
}

195
clause/operators.go Normal file
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package clause
import "strings"
type AddConditions []Interface
func (cs AddConditions) Build(builder BuilderInterface) {
for idx, c := range cs {
if idx > 0 {
builder.Write(" AND ")
}
c.Build(builder)
}
}
type ORConditions []Interface
func (cs ORConditions) Build(builder BuilderInterface) {
for idx, c := range cs {
if idx > 0 {
builder.Write(" OR ")
}
c.Build(builder)
}
}
type NotConditions []Interface
func (cs NotConditions) Build(builder BuilderInterface) {
for idx, c := range cs {
if idx > 0 {
builder.Write(" AND ")
}
if negationBuilder, ok := c.(NegationBuilder); ok {
negationBuilder.NegationBuild(builder)
} else {
builder.Write(" NOT ")
c.Build(builder)
}
}
}
// Raw raw sql for where
type Raw struct {
SQL string
Values []interface{}
}
func (raw Raw) Build(builder BuilderInterface) {
sql := raw.SQL
for _, v := range raw.Values {
sql = strings.Replace(sql, " ? ", " "+builder.AddVar(v)+" ", 1)
}
builder.Write(sql)
}
// IN Whether a value is within a set of values
type IN struct {
Column interface{}
Values []interface{}
}
func (in IN) Build(builder BuilderInterface) {
builder.WriteQuoted(in.Column)
if len(in.Values) == 0 {
builder.Write(" IN (NULL)")
} else {
builder.Write(" IN (", builder.AddVar(in.Values...), ")")
}
}
func (in IN) NegationBuild(builder BuilderInterface) {
if len(in.Values) != 0 {
builder.WriteQuoted(in.Column)
builder.Write(" NOT IN (", builder.AddVar(in.Values...), ")")
}
}
// Eq equal to for where
type Eq struct {
Column interface{}
Value interface{}
}
func (eq Eq) Build(builder BuilderInterface) {
builder.WriteQuoted(eq.Column)
if eq.Value == nil {
builder.Write(" IS NULL")
} else {
builder.Write(" = ", builder.AddVar(eq.Value))
}
}
func (eq Eq) NegationBuild(builder BuilderInterface) {
Neq{eq.Column, eq.Value}.Build(builder)
}
// Neq not equal to for where
type Neq struct {
Column interface{}
Value interface{}
}
func (neq Neq) Build(builder BuilderInterface) {
builder.WriteQuoted(neq.Column)
if neq.Value == nil {
builder.Write(" IS NOT NULL")
} else {
builder.Write(" <> ", builder.AddVar(neq.Value))
}
}
func (neq Neq) NegationBuild(builder BuilderInterface) {
Eq{neq.Column, neq.Value}.Build(builder)
}
// Gt greater than for where
type Gt struct {
Column interface{}
Value interface{}
}
func (gt Gt) Build(builder BuilderInterface) {
builder.WriteQuoted(gt.Column)
builder.Write(" > ", builder.AddVar(gt.Value))
}
func (gt Gt) NegationBuild(builder BuilderInterface) {
Lte{gt.Column, gt.Value}.Build(builder)
}
// Gte greater than or equal to for where
type Gte struct {
Column interface{}
Value interface{}
}
func (gte Gte) Build(builder BuilderInterface) {
builder.WriteQuoted(gte.Column)
builder.Write(" >= ", builder.AddVar(gte.Value))
}
func (gte Gte) NegationBuild(builder BuilderInterface) {
Lt{gte.Column, gte.Value}.Build(builder)
}
// Lt less than for where
type Lt struct {
Column interface{}
Value interface{}
}
func (lt Lt) Build(builder BuilderInterface) {
builder.WriteQuoted(lt.Column)
builder.Write(" < ", builder.AddVar(lt.Value))
}
func (lt Lt) NegationBuild(builder BuilderInterface) {
Gte{lt.Column, lt.Value}.Build(builder)
}
// Lte less than or equal to for where
type Lte struct {
Column interface{}
Value interface{}
}
func (lte Lte) Build(builder BuilderInterface) {
builder.WriteQuoted(lte.Column)
builder.Write(" <= ", builder.AddVar(lte.Value))
}
func (lte Lte) NegationBuild(builder BuilderInterface) {
Gt{lte.Column, lte.Value}.Build(builder)
}
// Like whether string matches regular expression
type Like struct {
Column interface{}
Value interface{}
}
func (like Like) Build(builder BuilderInterface) {
builder.WriteQuoted(like.Column)
builder.Write(" LIKE ", builder.AddVar(like.Value))
}
func (like Like) NegationBuild(builder BuilderInterface) {
builder.WriteQuoted(like.Column)
builder.Write(" NOT LIKE ", builder.AddVar(like.Value))
}

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finisher_api.go Normal file
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package gorm
import (
"database/sql"
)
func (db *DB) Count(sql string, values ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// First find first record that match given conditions, order by primary key
func (db *DB) First(out interface{}, where ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Take return a record that match given conditions, the order will depend on the database implementation
func (db *DB) Take(out interface{}, where ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Last find last record that match given conditions, order by primary key
func (db *DB) Last(out interface{}, where ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Find find records that match given conditions
func (db *DB) Find(out interface{}, where ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Scan scan value to a struct
func (db *DB) Row() *sql.Row {
// TODO
return nil
}
func (db *DB) Rows() (*sql.Rows, error) {
// TODO
return nil, nil
}
func (db *DB) Scan(dest interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) ScanRows(rows *sql.Rows, result interface{}) error {
return nil
}
// Create insert the value into database
func (db *DB) Create(value interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Save update value in database, if the value doesn't have primary key, will insert it
func (db *DB) Save(value interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Update update attributes with callbacks, refer: https://jinzhu.github.io/gorm/crud.html#update
func (db *DB) Update(column string, value interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Updates update attributes with callbacks, refer: https://jinzhu.github.io/gorm/crud.html#update
func (db *DB) Updates(values interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) UpdateColumn(attrs ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) UpdateColumns(values interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) FirstOrCreate(out interface{}, where ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) FirstOrInit(out interface{}, where ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
// Delete delete value match given conditions, if the value has primary key, then will including the primary key as condition
func (db *DB) Delete(value interface{}, where ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Related(value interface{}, foreignKeys ...string) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Transaction(fc func(tx *DB) error, opts ...*sql.TxOptions) (err error) {
panicked := true
tx := db.Begin(opts...)
defer func() {
// Make sure to rollback when panic, Block error or Commit error
if panicked || err != nil {
tx.Rollback()
}
}()
err = fc(tx)
if err == nil {
err = tx.Commit().Error
}
panicked = false
return
}
func (db *DB) Begin(opts ...*sql.TxOptions) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Commit() (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Rollback() (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Exec(sql string, values ...interface{}) (tx *DB) {
tx = db.getInstance()
return
}
func (db *DB) Association(column string) *Association {
return nil
}

62
gorm.go
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package gorm package gorm
import ( import (
"context"
"time" "time"
"github.com/jinzhu/gorm/clause"
"github.com/jinzhu/gorm/logger" "github.com/jinzhu/gorm/logger"
) )
@ -38,9 +40,69 @@ type Model struct {
// Dialector GORM database dialector // Dialector GORM database dialector
type Dialector interface { type Dialector interface {
Migrator() Migrator Migrator() Migrator
BindVar(stmt Statement, v interface{}) string
}
// Result
type Result struct {
Error error
RowsAffected int64
Statement *Statement
} }
// DB GORM DB definition // DB GORM DB definition
type DB struct { type DB struct {
*Config *Config
Dialector
Result
Context context.Context
}
// WithContext change current instance db's context to ctx
func (db *DB) WithContext(ctx context.Context) *DB {
tx := db.getInstance()
tx.Context = ctx
return tx
}
// Set store value with key into current db instance's context
func (db *DB) Set(key string, value interface{}) *DB {
tx := db.getInstance()
tx.Statement.Settings.Store(key, value)
return tx
}
// Get get value with key from current db instance's context
func (db *DB) Get(key string) (interface{}, bool) {
if db.Statement != nil {
return db.Statement.Settings.Load(key)
}
return nil, false
}
func (db *DB) Close() *DB {
// TODO
return db
}
func (db *DB) getInstance() *DB {
// db.Result.Statement == nil means root DB
if db.Result.Statement == nil {
return &DB{
Config: db.Config,
Dialector: db.Dialector,
Context: context.Background(),
Result: Result{
Statement: &Statement{DB: db, Clauses: map[string][]clause.Interface{}},
},
}
}
return db
}
// Debug start debug mode
func (db *DB) Debug() (tx *DB) {
tx = db.getInstance()
return
} }

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model/model.go Normal file
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package model
import (
"reflect"
)
type Model struct {
ModelType reflect.Type
Table string
PrioritizedPrimaryField *Field
PrimaryFields []*Field
Fields []*Field
FieldsByName map[string]*Field
FieldsByDBName map[string]*Field
Relationships Relationships
}
type Field struct {
Name string
DBName string
DataType reflect.Type
DBDataType string
Tag reflect.StructTag
TagSettings map[string]string
PrimaryKey bool
AutoIncrement bool
Creatable bool
Updatable bool
Nullable bool
Unique bool
Precision int
Size int
HasDefaultValue bool
DefaultValue string
StructField reflect.StructField
Model *Model
}

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model/relationship.go Normal file
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package model
// RelationshipType relationship type
type RelationshipType string
const (
HasOneRel RelationshipType = "has_one" // HasOneRel has one relationship
HasManyRel RelationshipType = "has_many" // HasManyRel has many relationship
BelongsToRel RelationshipType = "belongs_to" // BelongsToRel belongs to relationship
Many2ManyRel RelationshipType = "many_to_many" // Many2ManyRel many to many relationship
)
type Relationships struct {
HasOne map[string]*Relationship
BelongsTo map[string]*Relationship
HasMany map[string]*Relationship
Many2Many map[string]*Relationship
}
type Relationship struct {
Type RelationshipType
ForeignKeys []*RelationField // self
AssociationForeignKeys []*RelationField // association
JoinTable *JoinTable
}
type RelationField struct {
*Field
PolymorphicField *Field
PolymorphicValue string
}
type JoinTable struct {
Table string
ForeignKeys []*RelationField
AssociationForeignKeys []*RelationField
}

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statement.go Normal file
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package gorm
import (
"bytes"
"context"
"database/sql"
"fmt"
"strings"
"sync"
"github.com/jinzhu/gorm/clause"
)
// Statement statement
type Statement struct {
Dest interface{}
Table interface{}
Clauses map[string][]clause.Interface
Settings sync.Map
Context context.Context
DB *DB
StatementBuilder
}
// StatementBuilder statement builder
type StatementBuilder struct {
SQL bytes.Buffer
Vars []interface{}
NamedVars []sql.NamedArg
}
// Write write string
func (stmt Statement) Write(sql ...string) (err error) {
for _, s := range sql {
_, err = stmt.SQL.WriteString(s)
}
return
}
// WriteQuoted write quoted field
func (stmt Statement) WriteQuoted(field interface{}) (err error) {
_, err = stmt.SQL.WriteString(stmt.Quote(field))
return
}
// Write write string
func (stmt Statement) AddVar(vars ...interface{}) string {
var placeholders []string
for _, v := range vars {
if namedArg, ok := v.(sql.NamedArg); ok && len(namedArg.Name) > 0 {
stmt.NamedVars = append(stmt.NamedVars, namedArg)
placeholders = append(placeholders, "@"+namedArg.Name)
} else {
placeholders = append(placeholders, stmt.DB.Dialector.BindVar(stmt, v))
}
}
return strings.Join(placeholders, ",")
}
// Quote returns quoted value
func (stmt Statement) Quote(field interface{}) (str string) {
return fmt.Sprint(field)
}
// AddClause add clause
func (s Statement) AddClause(clause clause.Interface) {
s.Clauses[clause.Name()] = append(s.Clauses[clause.Name()], clause)
}