xugu_driver_go/xugu/xugu_rows.go

package xugu

// /查询结果：driver.Rows

import (
	"database/sql/driver"
	"encoding/binary"
	"errors"
	"fmt"
	"reflect"
)

// type Row struct {
// 	// Data information storage carrier of each column in the result set
// 	columns []FieldDescri
// 	// The name of each column in the result set of the current query
// 	names []string
// 	done  bool
// }

type xuguRows struct {
	// A context handle pointer, which can be used to obtain
	// information about the result set
	//result  unsafe.Pointer
	results *SelectResult
	// The return value of the function cgo_xgc_read_next()
	lastRowRelt int

	// The return value of the function cgo_xgc_next_result()
	lastRelt int
	// Boolean value, used to identify whether the executed
	// SQL statement has been prepared
	prepared bool

	// Context connection handle pointer
	rows_conn *xuguConn
	//rowset    Row
}

// Next用于把数据集中的下一行填入提供的slice中。该slice的
// 长度应该跟Columns()的长度一致
//
// 当没有数据行时，Next应该返回io.EOF
//
// dest不应被声明在Next之外(应该作为Next的一个成员变量)
// 关闭Rows时应特别注意，不要修改dest中缓冲区的值
func (row *xuguRows) Next(dest []driver.Value) error {
	fmt.Println(">>>>>(self *xuguRows) Next() ")
	if row.results.rowIdx >= len(row.results.Values[0]) {
		return errors.New("The result set has been released")
	}
	//	fmt.Println(" -- int(row.results.Field_Num)", int(row.results.Field_Num))
	for j := 0; j < int(row.results.Field_Num); j++ {

		coluType := row.results.Fields[j].FieldType
		//fmt.Println("  --coluType: ", coluType, row.results.Fields[j].typeDatabaseName())

		switch coluType {

		case fieldType_DATE:

		case fieldType_BINARY,
			fieldType_CLOB, fieldType_BLOB:

		case fieldType_TIME,
			fieldType_TIME_TZ:

		case fieldType_DATETIME,
			fieldType_DATETIME_TZ:
		case fieldType_I1:
			dest[j] = int8(row.results.Values[j][row.results.rowIdx].Col_Data[0])
		case fieldType_I4:

			dest[j] = binary.LittleEndian.Uint32(row.results.Values[j][row.results.rowIdx].Col_Data)

		default:

			//填入一行的数据
			//TODO这里长度改为一行长度
			dest[j] = make([]byte, len(row.results.Values))
			// Values[字段][0]
			dest[j] = row.results.Values[j][row.results.rowIdx].Col_Data

		}
	}
	row.results.rowIdx++

	return nil
}

// Columns返回列的名字集，它的个数是从slice的长度中推断出来的。
// 如果不知道特定的列名，应该为该条目返回一个空的字符串
func (row *xuguRows) Columns() []string {

	fmt.Println(">>>>>(self *xuguRows) Columns() ")
	// if row.results == nil {
	// 	return nil
	// }
	// if row.results.Fields != nil {
	// 	//return self.results.Fields
	// }

	//columns := make([]string, int(row.results.Field_Num))
	var columns []string

	for i, v := range row.results.Fields {
		columns = append(columns, v.FieldName)
		fmt.Printf("append(columns, v.FieldName) 个数%d ,%s", i+1, columns[i])
	}

	// fmt.Println(" -columns len  ", len(columns))

	// for i, v := range columns {

	// 	fmt.Println("  -columns:  ", i, v)
	// }
	return columns
}

func (row *xuguRows) ColumnTypeScanType(index int) reflect.Type {
	fmt.Println(">>>>>ColumnTypeScanType ")
	fmt.Printf("  -- row.results.Fields %#v \n", row.results.Fields[index].FieldType)
	fmt.Printf("  -- row.results.Fields %#v \n", row.results.Fields[index].scanType())
	return row.results.Fields[index].scanType()
}

func (self *xuguRows) Close() error {
	fmt.Println(">>>>>((self *xuguRows) Close() ")
	return nil
}