Golang ast.SelectField类代码示例

原作者: [db:作者] 来自: [db:来源] 收藏邀请

本文整理汇总了Golang中github.com/pingcap/tidb/ast.SelectField类的典型用法代码示例。如果您正苦于以下问题：Golang SelectField类的具体用法？Golang SelectField怎么用？Golang SelectField使用的例子？那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。

在下文中一共展示了SelectField类的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的Golang代码示例。

示例1: createResultFields

// createResultFields creates result field list for a single select field.
func (nr *nameResolver) createResultFields(field *ast.SelectField) (rfs []*ast.ResultField) {
	ctx := nr.currentContext()
	if field.WildCard != nil {
		if len(ctx.tables) == 0 {
			nr.Err = errors.New("No table used.")
			return
		}
		if field.WildCard.Table.L == "" {
			for _, v := range ctx.tables {
				rfs = append(rfs, v.GetResultFields()...)
			}
		} else {
			name := nr.tableUniqueName(field.WildCard.Schema, field.WildCard.Table)
			tableIdx, ok := ctx.tableMap[name]
			if !ok {
				nr.Err = errors.Errorf("unknown table %s.", field.WildCard.Table.O)
			}
			rfs = ctx.tables[tableIdx].GetResultFields()
		}
		return
	}
	// The column is visited before so it must has been resolved already.
	rf := &ast.ResultField{ColumnAsName: field.AsName}
	innerExpr := getInnerFromParentheses(field.Expr)
	switch v := innerExpr.(type) {
	case *ast.ColumnNameExpr:
		rf.Column = v.Refer.Column
		rf.Table = v.Refer.Table
		rf.DBName = v.Refer.DBName
		rf.TableName = v.Refer.TableName
		rf.Expr = v.Refer.Expr
	default:
		rf.Column = &model.ColumnInfo{} // Empty column info.
		rf.Table = &model.TableInfo{}   // Empty table info.
		rf.Expr = v
	}
	if field.AsName.L == "" {
		switch x := innerExpr.(type) {
		case *ast.ColumnNameExpr:
			rf.ColumnAsName = model.NewCIStr(x.Name.Name.O)
		case *ast.ValueExpr:
			if innerExpr.Text() != "" {
				rf.ColumnAsName = model.NewCIStr(innerExpr.Text())
			} else {
				rf.ColumnAsName = model.NewCIStr(field.Text())
			}
		default:
			rf.ColumnAsName = model.NewCIStr(field.Text())
		}
	}
	rfs = append(rfs, rf)
	return
}

开发者ID:xudongQiu，项目名称:tidb，代码行数:54，代码来源:resolver.go

示例2: createResultFields

// createResultFields creates result field list for a single select field.
func (nr *nameResolver) createResultFields(field *ast.SelectField) (rfs []*ast.ResultField) {
	ctx := nr.currentContext()
	if field.WildCard != nil {
		if len(ctx.tables) == 0 {
			nr.Err = errors.New("No table used.")
			return
		}
		tableRfs := []*ast.ResultField{}
		if field.WildCard.Table.L == "" {
			for _, v := range ctx.tables {
				tableRfs = append(tableRfs, v.GetResultFields()...)
			}
		} else {
			name := nr.tableUniqueName(field.WildCard.Schema, field.WildCard.Table)
			tableIdx, ok1 := ctx.tableMap[name]
			derivedTableIdx, ok2 := ctx.derivedTableMap[name]
			if !ok1 && !ok2 {
				nr.Err = errors.Errorf("unknown table %s.", field.WildCard.Table.O)
			}
			if ok1 {
				tableRfs = ctx.tables[tableIdx].GetResultFields()
			}
			if ok2 {
				tableRfs = append(tableRfs, ctx.tables[derivedTableIdx].GetResultFields()...)
			}

		}
		for _, trf := range tableRfs {
			// Convert it to ColumnNameExpr
			cn := &ast.ColumnName{
				Schema: trf.DBName,
				Table:  trf.Table.Name,
				Name:   trf.ColumnAsName,
			}
			cnExpr := &ast.ColumnNameExpr{
				Name:  cn,
				Refer: trf,
			}
			ast.SetFlag(cnExpr)
			cnExpr.SetType(trf.Expr.GetType())
			rf := *trf
			rf.Expr = cnExpr
			rfs = append(rfs, &rf)
		}
		return
	}
	// The column is visited before so it must has been resolved already.
	rf := &ast.ResultField{ColumnAsName: field.AsName}
	innerExpr := getInnerFromParentheses(field.Expr)
	switch v := innerExpr.(type) {
	case *ast.ColumnNameExpr:
		rf.Column = v.Refer.Column
		rf.Table = v.Refer.Table
		rf.DBName = v.Refer.DBName
		rf.TableName = v.Refer.TableName
		rf.Expr = v
	default:
		rf.Column = &model.ColumnInfo{} // Empty column info.
		rf.Table = &model.TableInfo{}   // Empty table info.
		rf.Expr = v
	}
	if field.AsName.L == "" {
		switch x := innerExpr.(type) {
		case *ast.ColumnNameExpr:
			rf.ColumnAsName = model.NewCIStr(x.Name.Name.O)
		case *ast.ValueExpr:
			if innerExpr.Text() != "" {
				rf.ColumnAsName = model.NewCIStr(innerExpr.Text())
			} else {
				rf.ColumnAsName = model.NewCIStr(field.Text())
			}
		default:
			rf.ColumnAsName = model.NewCIStr(field.Text())
		}
	}
	rfs = append(rfs, rf)
	return
}

开发者ID:youprofit，项目名称:tidb，代码行数:79，代码来源:resolver.go

注：本文中的github.com/pingcap/tidb/ast.SelectField类示例由纯净天空整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。