improve gdb.Update/Delete feature to support orderby/limit features

g/database/gdb/gdb.go

@@ -14,13 +14,14 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"time"
+
 	"github.com/gogf/gf/g/container/gmap"
 	"github.com/gogf/gf/g/container/gring"
 	"github.com/gogf/gf/g/container/gtype"
 	"github.com/gogf/gf/g/container/gvar"
 	"github.com/gogf/gf/g/os/gcache"
 	"github.com/gogf/gf/g/util/grand"
-	"time"
 )
 
 // 数据库操作接口

g/database/gdb/gdb_base.go

@@ -11,13 +11,14 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"reflect"
+	"strings"
+
 	"github.com/gogf/gf/g/container/gvar"
 	"github.com/gogf/gf/g/os/gcache"
 	"github.com/gogf/gf/g/os/gtime"
 	"github.com/gogf/gf/g/text/gregex"
 	"github.com/gogf/gf/g/util/gconv"
-	"reflect"
-	"strings"
 )
 
 const (
@@ -498,7 +499,10 @@ func (bs *dbBase) doBatchInsert(link dbLink, table string, list interface{}, opt
 // CURD操作:数据更新，统一采用sql预处理。
 // data参数支持string/map/struct/*struct类型。
 func (bs *dbBase) Update(table string, data interface{}, condition interface{}, args ...interface{}) (sql.Result, error) {
-	newWhere, newArgs := formatCondition(condition, args)
+	newWhere, newArgs := formatWhere(condition, args)
+	if newWhere != "" {
+		newWhere = " WHERE " + newWhere
+	}
 	return bs.db.doUpdate(nil, table, data, newWhere, newArgs...)
 }
 
@@ -537,15 +541,15 @@ func (bs *dbBase) doUpdate(link dbLink, table string, data interface{}, conditio
 			return nil, err
 		}
 	}
-	if len(condition) == 0 {
-		return bs.db.doExec(link, fmt.Sprintf("UPDATE %s SET %s", table, updates), args...)
-	}
-	return bs.db.doExec(link, fmt.Sprintf("UPDATE %s SET %s WHERE %s", table, updates, condition), args...)
+	return bs.db.doExec(link, fmt.Sprintf("UPDATE %s SET %s%s", table, updates, condition), args...)
 }
 
 // CURD操作:删除数据
 func (bs *dbBase) Delete(table string, condition interface{}, args ...interface{}) (result sql.Result, err error) {
-	newWhere, newArgs := formatCondition(condition, args)
+	newWhere, newArgs := formatWhere(condition, args)
+	if newWhere != "" {
+		newWhere = " WHERE " + newWhere
+	}
 	return bs.db.doDelete(nil, table, newWhere, newArgs...)
 }
 
@@ -556,10 +560,7 @@ func (bs *dbBase) doDelete(link dbLink, table string, condition string, args ...
 			return nil, err
 		}
 	}
-	if len(condition) == 0 {
-		return bs.db.doExec(link, fmt.Sprintf("DELETE FROM %s", table), args...)
-	}
-	return bs.db.doExec(link, fmt.Sprintf("DELETE FROM %s WHERE %s", table, condition), args...)
+	return bs.db.doExec(link, fmt.Sprintf("DELETE FROM %s%s", table, condition), args...)
 }
 
 // 获得缓存对象
@@ -570,12 +571,15 @@ func (bs *dbBase) getCache() *gcache.Cache {
 // 将数据查询的列表数据*sql.Rows转换为Result类型
 func (bs *dbBase) rowsToResult(rows *sql.Rows) (Result, error) {
 	// 列信息列表, 名称与类型
-	types := make([]string, 0)
-	columns := make([]string, 0)
-	columnTypes, _ := rows.ColumnTypes()
-	for _, t := range columnTypes {
-		types = append(types, t.DatabaseTypeName())
-		columns = append(columns, t.Name())
+	columnTypes, err := rows.ColumnTypes()
+	if err != nil {
+		return nil, err
+	}
+	types := make([]string, len(columnTypes))
+	columns := make([]string, len(columnTypes))
+	for k, v := range columnTypes {
+		types[k] = v.DatabaseTypeName()
+		columns[k] = v.Name()
 	}
 	// 返回结构组装
 	values := make([]sql.RawBytes, len(columns))
@@ -589,14 +593,15 @@ func (bs *dbBase) rowsToResult(rows *sql.Rows) (Result, error) {
 			return records, err
 		}
 		row := make(Record)
-		// 注意col字段是一个[]byte类型(slice类型本身是一个指针)，多个记录循环时该变量指向的是同一个内存地址
-		for i, col := range values {
-			if col == nil {
+		// 注意col字段是一个[]byte类型(slice类型本身是一个引用类型)，
+		// 多个记录循环时该变量指向的是同一个内存地址
+		for i, column := range values {
+			if column == nil {
 				row[columns[i]] = gvar.New(nil, true)
 			} else {
 				// 由于 sql.RawBytes 是slice类型, 这里必须使用值复制
-				v := make([]byte, len(col))
-				copy(v, col)
+				v := make([]byte, len(column))
+				copy(v, column)
 				row[columns[i]] = gvar.New(bs.db.convertValue(v, types[i]), true)
 			}
 		}

g/database/gdb/gdb_func.go

@@ -10,14 +10,15 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"reflect"
+	"strings"
+	"time"
+
 	"github.com/gogf/gf/g/os/glog"
 	"github.com/gogf/gf/g/os/gtime"
 	"github.com/gogf/gf/g/text/gregex"
 	"github.com/gogf/gf/g/text/gstr"
 	"github.com/gogf/gf/g/util/gconv"
-	"reflect"
-	"strings"
-	"time"
 )
 
 // Type assert api for String().
@@ -25,8 +26,8 @@ type apiString interface {
 	String() string
 }
 
-// 格式化SQL查询条件
-func formatCondition(where interface{}, args []interface{}) (newWhere string, newArgs []interface{}) {
+// 格式化Where查询条件
+func formatWhere(where interface{}, args []interface{}) (newWhere string, newArgs []interface{}) {
 	// 条件字符串处理
 	buffer := bytes.NewBuffer(nil)
 	// 使用反射进行类型判断

g/database/gdb/gdb_model.go

@@ -12,8 +12,9 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
-	"github.com/gogf/gf/g/util/gconv"
 	"reflect"
+
+	"github.com/gogf/gf/g/util/gconv"
 )
 
 // 数据库链式操作模型对象
@@ -29,13 +30,13 @@ type Model struct {
 	orderBy      string        // 排序语句
 	start        int           // 分页开始
 	limit        int           // 分页条数
-	data         interface{}   // 操作记录(支持Map/List/string类型)
+	data         interface{}   // 操作数据(注意仅支持Map/List/string类型)
 	batch        int           // 批量操作条数
 	filter       bool          // 是否按照表字段过滤data参数
 	cacheEnabled bool          // 当前SQL操作是否开启查询缓存功能
 	cacheTime    int           // 查询缓存时间
 	cacheName    string        // 查询缓存名称
-	safe         bool          // 当前模型是否运行安全模式（可修改当前模型，否则每一次链式操作都是返回新的模型对象）
+	safe         bool          // 当前模型是否安全模式（默认非安全表示链式操作直接修改当前模型属性；否则每一次链式操作都是返回新的模型对象）
 }
 
 // 链式操作，数据表字段，可支持多个表，以半角逗号连接
@@ -45,6 +46,7 @@ func (bs *dbBase) Table(tables string) *Model {
 		tablesInit: tables,
 		tables:     tables,
 		fields:     "*",
+		start:      -1,
 		safe:       false,
 	}
 }
@@ -149,7 +151,7 @@ func (md *Model) Where(where interface{}, args ...interface{}) *Model {
 	if model.where != "" {
 		return md.And(where, args...)
 	}
-	newWhere, newArgs := formatCondition(where, args)
+	newWhere, newArgs := formatWhere(where, args)
 	model.where = newWhere
 	model.whereArgs = newArgs
 	return model
@@ -158,7 +160,7 @@ func (md *Model) Where(where interface{}, args ...interface{}) *Model {
 // 链式操作，添加AND条件到Where中
 func (md *Model) And(where interface{}, args ...interface{}) *Model {
 	model := md.getModel()
-	newWhere, newArgs := formatCondition(where, args)
+	newWhere, newArgs := formatWhere(where, args)
 	if len(model.where) > 0 && model.where[0] == '(' {
 		model.where = fmt.Sprintf(`%s AND (%s)`, model.where, newWhere)
 	} else {
@@ -171,7 +173,7 @@ func (md *Model) And(where interface{}, args ...interface{}) *Model {
 // 链式操作，添加OR条件到Where中
 func (md *Model) Or(where interface{}, args ...interface{}) *Model {
 	model := md.getModel()
-	newWhere, newArgs := formatCondition(where, args)
+	newWhere, newArgs := formatWhere(where, args)
 	if len(model.where) > 0 && model.where[0] == '(' {
 		model.where = fmt.Sprintf(`%s OR (%s)`, model.where, newWhere)
 	} else {
@@ -195,11 +197,20 @@ func (md *Model) OrderBy(orderBy string) *Model {
 	return model
 }
 
-// 链式操作，limit
-func (md *Model) Limit(start int, limit int) *Model {
+// 链式操作，limit。
+//
+// 如果给定一个参数，那么生成的SQL为：LIMIT limit[0]
+//
+// 如果给定两个参数，那么生成的SQL为：LIMIT limit[0], limit[1]
+func (md *Model) Limit(limit ...int) *Model {
 	model := md.getModel()
-	model.start = start
-	model.limit = limit
+	switch len(limit) {
+	case 1:
+		model.limit = limit[0]
+	case 2:
+		model.start = limit[0]
+		model.limit = limit[1]
+	}
 	return model
 }
 
@@ -425,9 +436,9 @@ func (md *Model) Update() (result sql.Result, err error) {
 		}
 	}
 	if md.tx == nil {
-		return md.db.doUpdate(nil, md.tables, md.data, md.where, md.whereArgs...)
+		return md.db.doUpdate(nil, md.tables, md.data, md.getConditionSql(), md.whereArgs...)
 	} else {
-		return md.tx.doUpdate(md.tables, md.data, md.where, md.whereArgs...)
+		return md.tx.doUpdate(md.tables, md.data, md.getConditionSql(), md.whereArgs...)
 	}
 }
 
@@ -439,9 +450,9 @@ func (md *Model) Delete() (result sql.Result, err error) {
 		}
 	}()
 	if md.tx == nil {
-		return md.db.doDelete(nil, md.tables, md.where, md.whereArgs...)
+		return md.db.doDelete(nil, md.tables, md.getConditionSql(), md.whereArgs...)
 	} else {
-		return md.tx.doDelete(md.tables, md.where, md.whereArgs...)
+		return md.tx.doDelete(md.tables, md.getConditionSql(), md.whereArgs...)
 	}
 }
 
@@ -452,7 +463,7 @@ func (md *Model) Select() (Result, error) {
 
 // 链式操作，查询所有记录
 func (md *Model) All() (Result, error) {
-	return md.getAll(md.getFormattedSql(), md.whereArgs...)
+	return md.getAll(fmt.Sprintf("SELECT %s FROM %s %s", md.fields, md.tables, md.getConditionSql()), md.whereArgs...)
 }
 
 // 链式操作，查询单条记录
@@ -530,7 +541,7 @@ func (md *Model) Count() (int, error) {
 	} else {
 		md.fields = fmt.Sprintf(`COUNT(%s)`, md.fields)
 	}
-	s := md.getFormattedSql()
+	s := fmt.Sprintf("SELECT %s FROM %s %s", md.fields, md.tables, md.getConditionSql())
 	if len(md.groupBy) > 0 {
 		s = fmt.Sprintf("SELECT COUNT(1) FROM (%s) count_alias", s)
 	}
@@ -583,12 +594,9 @@ func (md *Model) checkAndRemoveCache() {
 	}
 }
 
-// 格式化当前输入参数，返回可执行的SQL语句（不带参数）
-func (md *Model) getFormattedSql() string {
-	if md.fields == "" {
-		md.fields = "*"
-	}
-	s := fmt.Sprintf("SELECT %s FROM %s", md.fields, md.tables)
+// 格式化当前输入参数，返回SQL条件语句（不带参数）
+func (md *Model) getConditionSql() string {
+	s := ""
 	if md.where != "" {
 		s += " WHERE " + md.where
 	}
@@ -599,7 +607,12 @@ func (md *Model) getFormattedSql() string {
 		s += " ORDER BY " + md.orderBy
 	}
 	if md.limit != 0 {
-		s += fmt.Sprintf(" LIMIT %d, %d", md.start, md.limit)
+		if md.start >= 0 {
+			s += fmt.Sprintf(" LIMIT %d, %d", md.start, md.limit)
+		} else {
+			s += fmt.Sprintf(" LIMIT %d", md.limit)
+		}
+
 	}
 	return s
 }

g/database/gdb/gdb_transaction.go

@@ -9,8 +9,9 @@ package gdb
 import (
 	"database/sql"
 	"fmt"
-	"github.com/gogf/gf/g/text/gregex"
 	"reflect"
+
+	"github.com/gogf/gf/g/text/gregex"
 )
 
 // 数据库事务对象
@@ -164,7 +165,10 @@ func (tx *TX) BatchSave(table string, list interface{}, batch ...int) (sql.Resul
 // CURD操作:数据更新，统一采用sql预处理,
 // data参数支持字符串或者关联数组类型，内部会自行做判断处理.
 func (tx *TX) Update(table string, data interface{}, condition interface{}, args ...interface{}) (sql.Result, error) {
-	newWhere, newArgs := formatCondition(condition, args)
+	newWhere, newArgs := formatWhere(condition, args)
+	if newWhere != "" {
+		newWhere = " WHERE " + newWhere
+	}
 	return tx.doUpdate(table, data, newWhere, newArgs...)
 }
 
@@ -175,7 +179,10 @@ func (tx *TX) doUpdate(table string, data interface{}, condition string, args ..
 
 // CURD操作:删除数据
 func (tx *TX) Delete(table string, condition interface{}, args ...interface{}) (sql.Result, error) {
-	newWhere, newArgs := formatCondition(condition, args)
+	newWhere, newArgs := formatWhere(condition, args)
+	if newWhere != "" {
+		newWhere = " WHERE " + newWhere
+	}
 	return tx.doDelete(table, newWhere, newArgs...)
 }
 

g/database/gdb/gdb_unit_init_test.go

@@ -8,12 +8,14 @@ package gdb_test
 
 import (
 	"fmt"
+	"os"
+
 	"github.com/gogf/gf/g"
 	"github.com/gogf/gf/g/container/garray"
+
 	"github.com/gogf/gf/g/database/gdb"
 	"github.com/gogf/gf/g/os/gtime"
 	"github.com/gogf/gf/g/test/gtest"
-	"os"
 )
 
 const (
@@ -88,14 +90,6 @@ func createTable(table ...string) (name string) {
 	return
 }
 
-// 删除指定表.
-func dropTable(table string) {
-	if _, err := db.Exec(fmt.Sprintf("DROP TABLE IF EXISTS `%s`", table)); err != nil {
-		gtest.Fatal(err)
-	}
-}
-
-// See createTable.
 // 创建测试表，并初始化默认数据。
 func createInitTable(table ...string) (name string) {
 	name = createTable(table...)
@@ -117,3 +111,10 @@ func createInitTable(table ...string) (name string) {
 	gtest.Assert(n, INIT_DATA_SIZE)
 	return
 }
+
+// 删除指定表.
+func dropTable(table string) {
+	if _, err := db.Exec(fmt.Sprintf("DROP TABLE IF EXISTS `%s`", table)); err != nil {
+		gtest.Fatal(err)
+	}
+}

g/database/gdb/gdb_unit_model_test.go

@@ -7,10 +7,11 @@
 package gdb_test
 
 import (
+	"testing"
+
 	"github.com/gogf/gf/g"
 	"github.com/gogf/gf/g/os/gtime"
 	"github.com/gogf/gf/g/test/gtest"
-	"testing"
 )
 
 // 基本测试
@@ -187,6 +188,25 @@ func TestModel_Save(t *testing.T) {
 }
 
 func TestModel_Update(t *testing.T) {
+	table := createInitTable()
+	// UPDATE...LIMIT
+	gtest.Case(t, func() {
+		result, err := db.Table(table).Data("nickname", "T100").OrderBy("id desc").Limit(2).Update()
+		if err != nil {
+			gtest.Fatal(err)
+		}
+		n, _ := result.RowsAffected()
+		gtest.Assert(n, 2)
+
+		v1, err := db.Table(table).Fields("nickname").Where("id", 10).Value()
+		gtest.Assert(err, nil)
+		gtest.Assert(v1.String(), "T100")
+
+		v2, err := db.Table(table).Fields("nickname").Where("id", 8).Value()
+		gtest.Assert(err, nil)
+		gtest.Assert(v2.String(), "T8")
+	})
+
 	gtest.Case(t, func() {
 		result, err := db.Table("user").Data("passport", "t22").Where("passport=?", "t2").Update()
 		if err != nil {
@@ -644,10 +664,22 @@ func TestModel_Where(t *testing.T) {
 }
 
 func TestModel_Delete(t *testing.T) {
-	result, err := db.Table("user").Delete()
-	if err != nil {
-		gtest.Fatal(err)
-	}
-	n, _ := result.RowsAffected()
-	gtest.Assert(n, 3)
+	// DELETE...LIMIT
+	gtest.Case(t, func() {
+		result, err := db.Table("user").Limit(2).Delete()
+		if err != nil {
+			gtest.Fatal(err)
+		}
+		n, _ := result.RowsAffected()
+		gtest.Assert(n, 2)
+	})
+
+	gtest.Case(t, func() {
+		result, err := db.Table("user").Delete()
+		if err != nil {
+			gtest.Fatal(err)
+		}
+		n, _ := result.RowsAffected()
+		gtest.Assert(n, 1)
+	})
 }

geg/database/gdb/mysql/gdb_debug.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+
 	"github.com/gogf/gf/g"
 	"github.com/gogf/gf/g/database/gdb"
 	"github.com/gogf/gf/g/os/glog"
@@ -22,8 +23,11 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	glog.SetPath("/tmp")
 	db.SetDebug(true)
+	db.Table("user").Limit(2).Delete()
+	return
+	glog.SetPath("/tmp")
+
 	// 执行3条SQL查询
 	for i := 1; i <= 3; i++ {
 		db.Table("user").Where("uid=?", i).One()