gf/database/gdb/gdb_model.go
2022-02-16 00:26:06 +08:00

326 lines
11 KiB
Go

// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.
package gdb
import (
"context"
"fmt"
"github.com/gogf/gf/v2/text/gregex"
"github.com/gogf/gf/v2/text/gstr"
"github.com/gogf/gf/v2/util/gconv"
)
// Model is core struct implementing the DAO for ORM.
type Model struct {
db DB // Underlying DB interface.
tx *TX // Underlying TX interface.
rawSql string // rawSql is the raw SQL string which marks a raw SQL based Model not a table based Model.
schema string // Custom database schema.
linkType int // Mark for operation on master or slave.
tablesInit string // Table names when model initialization.
tables string // Operation table names, which can be more than one table names and aliases, like: "user", "user u", "user u, user_detail ud".
fields string // Operation fields, multiple fields joined using char ','.
fieldsEx string // Excluded operation fields, multiple fields joined using char ','.
withArray []interface{} // Arguments for With feature.
withAll bool // Enable model association operations on all objects that have "with" tag in the struct.
extraArgs []interface{} // Extra custom arguments for sql, which are prepended to the arguments before sql committed to underlying driver.
whereHolder []ModelWhereHolder // Condition strings for where operation.
groupBy string // Used for "group by" statement.
orderBy string // Used for "order by" statement.
having []interface{} // Used for "having..." statement.
start int // Used for "select ... start, limit ..." statement.
limit int // Used for "select ... start, limit ..." statement.
option int // Option for extra operation features.
offset int // Offset statement for some databases grammar.
data interface{} // Data for operation, which can be type of map/[]map/struct/*struct/string, etc.
batch int // Batch number for batch Insert/Replace/Save operations.
filter bool // Filter data and where key-value pairs according to the fields of the table.
distinct string // Force the query to only return distinct results.
lockInfo string // Lock for update or in shared lock.
cacheEnabled bool // Enable sql result cache feature, which is mainly for indicating cache duration(especially 0) usage.
cacheOption CacheOption // Cache option for query statement.
unscoped bool // Disables soft deleting features when select/delete operations.
safe bool // If true, it clones and returns a new model object whenever operation done; or else it changes the attribute of current model.
onDuplicate interface{} // onDuplicate is used for ON "DUPLICATE KEY UPDATE" statement.
onDuplicateEx interface{} // onDuplicateEx is used for excluding some columns ON "DUPLICATE KEY UPDATE" statement.
}
// ModelHandler is a function that handles given Model and returns a new Model that is custom modified.
type ModelHandler func(m *Model) *Model
// ChunkHandler is a function that is used in function Chunk, which handles given Result and error.
// It returns true if it wants to continue chunking, or else it returns false to stop chunking.
type ChunkHandler func(result Result, err error) bool
// ModelWhereHolder is the holder for where condition preparing.
type ModelWhereHolder struct {
Type string // Type of this holder.
Operator int // Operator for this holder.
Where interface{} // Where parameter, which can commonly be type of string/map/struct.
Args []interface{} // Arguments for where parameter.
Prefix string // Field prefix, eg: "user.", "order.".
}
const (
linkTypeMaster = 1
linkTypeSlave = 2
defaultFields = "*"
whereHolderOperatorWhere = 1
whereHolderOperatorAnd = 2
whereHolderOperatorOr = 3
whereHolderTypeDefault = "Default"
whereHolderTypeNoArgs = "NoArgs"
whereHolderTypeIn = "In"
)
// Model creates and returns a new ORM model from given schema.
// The parameter `tableNameQueryOrStruct` can be more than one table names, and also alias name, like:
// 1. Model names:
// db.Model("user")
// db.Model("user u")
// db.Model("user, user_detail")
// db.Model("user u, user_detail ud")
// 2. Model name with alias:
// db.Model("user", "u")
// 3. Model name with sub-query:
// db.Model("? AS a, ? AS b", subQuery1, subQuery2)
func (c *Core) Model(tableNameQueryOrStruct ...interface{}) *Model {
var (
tableStr string
tableName string
extraArgs []interface{}
)
// Model creation with sub-query.
if len(tableNameQueryOrStruct) > 1 {
conditionStr := gconv.String(tableNameQueryOrStruct[0])
if gstr.Contains(conditionStr, "?") {
whereHolder := ModelWhereHolder{
Where: conditionStr,
Args: tableNameQueryOrStruct[1:],
}
tableStr, extraArgs = formatWhereHolder(c.db, formatWhereHolderInput{
ModelWhereHolder: whereHolder,
OmitNil: false,
OmitEmpty: false,
Schema: "",
Table: "",
})
}
}
// Normal model creation.
if tableStr == "" {
tableNames := make([]string, len(tableNameQueryOrStruct))
for k, v := range tableNameQueryOrStruct {
if s, ok := v.(string); ok {
tableNames[k] = s
} else if tableName = getTableNameFromOrmTag(v); tableName != "" {
tableNames[k] = tableName
}
}
if len(tableNames) > 1 {
tableStr = fmt.Sprintf(
`%s AS %s`, c.QuotePrefixTableName(tableNames[0]), c.QuoteWord(tableNames[1]),
)
} else if len(tableNames) == 1 {
tableStr = c.QuotePrefixTableName(tableNames[0])
}
}
m := &Model{
db: c.db,
schema: c.schema,
tablesInit: tableStr,
tables: tableStr,
fields: defaultFields,
start: -1,
offset: -1,
filter: true,
extraArgs: extraArgs,
}
if defaultModelSafe {
m.safe = true
}
return m
}
// Raw creates and returns a model based on a raw sql not a table.
// Example:
// db.Raw("SELECT * FROM `user` WHERE `name` = ?", "john").Scan(&result)
func (c *Core) Raw(rawSql string, args ...interface{}) *Model {
model := c.Model()
model.rawSql = rawSql
model.extraArgs = args
return model
}
// Raw sets current model as a raw sql model.
// Example:
// db.Raw("SELECT * FROM `user` WHERE `name` = ?", "john").Scan(&result)
// See Core.Raw.
func (m *Model) Raw(rawSql string, args ...interface{}) *Model {
model := m.db.Raw(rawSql, args...)
model.db = m.db
model.tx = m.tx
return model
}
func (tx *TX) Raw(rawSql string, args ...interface{}) *Model {
return tx.Model().Raw(rawSql, args...)
}
// With creates and returns an ORM model based on metadata of given object.
func (c *Core) With(objects ...interface{}) *Model {
return c.db.Model().With(objects...)
}
// Model acts like Core.Model except it operates on transaction.
// See Core.Model.
func (tx *TX) Model(tableNameQueryOrStruct ...interface{}) *Model {
model := tx.db.Model(tableNameQueryOrStruct...)
model.db = tx.db
model.tx = tx
return model
}
// With acts like Core.With except it operates on transaction.
// See Core.With.
func (tx *TX) With(object interface{}) *Model {
return tx.Model().With(object)
}
// Ctx sets the context for current operation.
func (m *Model) Ctx(ctx context.Context) *Model {
if ctx == nil {
return m
}
model := m.getModel()
model.db = model.db.Ctx(ctx)
if m.tx != nil {
model.tx = model.tx.Ctx(ctx)
}
return model
}
// GetCtx returns the context for current Model.
// It returns `context.Background()` is there's no context previously set.
func (m *Model) GetCtx() context.Context {
if m.tx != nil && m.tx.ctx != nil {
return m.tx.ctx
}
return m.db.GetCtx()
}
// As sets an alias name for current table.
func (m *Model) As(as string) *Model {
if m.tables != "" {
model := m.getModel()
split := " JOIN "
if gstr.ContainsI(model.tables, split) {
// For join table.
array := gstr.Split(model.tables, split)
array[len(array)-1], _ = gregex.ReplaceString(`(.+) ON`, fmt.Sprintf(`$1 AS %s ON`, as), array[len(array)-1])
model.tables = gstr.Join(array, split)
} else {
// For base table.
model.tables = gstr.TrimRight(model.tables) + " AS " + as
}
return model
}
return m
}
// DB sets/changes the db object for current operation.
func (m *Model) DB(db DB) *Model {
model := m.getModel()
model.db = db
return model
}
// TX sets/changes the transaction for current operation.
func (m *Model) TX(tx *TX) *Model {
model := m.getModel()
model.db = tx.db
model.tx = tx
return model
}
// Schema sets the schema for current operation.
func (m *Model) Schema(schema string) *Model {
model := m.getModel()
model.schema = schema
return model
}
// Clone creates and returns a new model which is a clone of current model.
// Note that it uses deep-copy for the clone.
func (m *Model) Clone() *Model {
newModel := (*Model)(nil)
if m.tx != nil {
newModel = m.tx.Model(m.tablesInit)
} else {
newModel = m.db.Model(m.tablesInit)
}
*newModel = *m
// Shallow copy slice attributes.
if n := len(m.extraArgs); n > 0 {
newModel.extraArgs = make([]interface{}, n)
copy(newModel.extraArgs, m.extraArgs)
}
if n := len(m.whereHolder); n > 0 {
newModel.whereHolder = make([]ModelWhereHolder, n)
copy(newModel.whereHolder, m.whereHolder)
}
if n := len(m.withArray); n > 0 {
newModel.withArray = make([]interface{}, n)
copy(newModel.withArray, m.withArray)
}
return newModel
}
// Master marks the following operation on master node.
func (m *Model) Master() *Model {
model := m.getModel()
model.linkType = linkTypeMaster
return model
}
// Slave marks the following operation on slave node.
// Note that it makes sense only if there's any slave node configured.
func (m *Model) Slave() *Model {
model := m.getModel()
model.linkType = linkTypeSlave
return model
}
// Safe marks this model safe or unsafe. If safe is true, it clones and returns a new model object
// whenever the operation done, or else it changes the attribute of current model.
func (m *Model) Safe(safe ...bool) *Model {
if len(safe) > 0 {
m.safe = safe[0]
} else {
m.safe = true
}
return m
}
// Args sets custom arguments for model operation.
func (m *Model) Args(args ...interface{}) *Model {
model := m.getModel()
model.extraArgs = append(model.extraArgs, args)
return model
}
// Handler calls each of `handlers` on current Model and returns a new Model.
// ModelHandler is a function that handles given Model and returns a new Model that is custom modified.
func (m *Model) Handler(handlers ...ModelHandler) *Model {
model := m.getModel()
for _, handler := range handlers {
model = handler(model)
}
return model
}