当前位置: 首页>>代码示例>>Golang>>正文


Golang SelectStmt.GetResultFields方法代码示例

本文整理汇总了Golang中github.com/pingcap/tidb/ast.SelectStmt.GetResultFields方法的典型用法代码示例。如果您正苦于以下问题:Golang SelectStmt.GetResultFields方法的具体用法?Golang SelectStmt.GetResultFields怎么用?Golang SelectStmt.GetResultFields使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在github.com/pingcap/tidb/ast.SelectStmt的用法示例。


在下文中一共展示了SelectStmt.GetResultFields方法的10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,您的评价将有助于系统推荐出更棒的Golang代码示例。

示例1: buildSelect

func (b *planBuilder) buildSelect(sel *ast.SelectStmt) Plan {
	var aggFuncs []*ast.AggregateFuncExpr
	hasAgg := b.detectSelectAgg(sel)
	if hasAgg {
		aggFuncs = b.extractSelectAgg(sel)
	}
	var p Plan
	if sel.From != nil {
		p = b.buildJoin(sel.From.TableRefs)
		if b.err != nil {
			return nil
		}
		if sel.Where != nil {
			p = b.buildFilter(p, sel.Where)
			if b.err != nil {
				return nil
			}
		}
		if sel.LockTp != ast.SelectLockNone {
			p = b.buildSelectLock(p, sel.LockTp)
			if b.err != nil {
				return nil
			}
		}
		if hasAgg {
			p = b.buildAggregate(p, aggFuncs, sel.GroupBy)
		}
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
	} else {
		if hasAgg {
			p = b.buildAggregate(p, aggFuncs, nil)
		}
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
		if sel.Where != nil {
			p = b.buildFilter(p, sel.Where)
			if b.err != nil {
				return nil
			}
		}
	}
	if sel.OrderBy != nil {
		p = b.buildSort(p, sel.OrderBy.Items)
		if b.err != nil {
			return nil
		}
	}
	if sel.Limit != nil {
		p = b.buildLimit(p, sel.Limit)
		if b.err != nil {
			return nil
		}
	}
	return p
}
开发者ID:zxylvlp,项目名称:tidb,代码行数:60,代码来源:planbuilder.go

示例2: buildSelect

func (b *planBuilder) buildSelect(sel *ast.SelectStmt) Plan {
	var aggFuncs []*ast.AggregateFuncExpr
	hasAgg := b.detectSelectAgg(sel)
	if hasAgg {
		aggFuncs = b.extractSelectAgg(sel)
	}
	// Build subquery
	// Convert subquery to expr with plan
	b.buildSubquery(sel)
	var p Plan
	if sel.From != nil {
		p = b.buildFrom(sel)
		if b.err != nil {
			return nil
		}
		if sel.LockTp != ast.SelectLockNone {
			p = b.buildSelectLock(p, sel.LockTp)
			if b.err != nil {
				return nil
			}
		}
		if hasAgg {
			p = b.buildAggregate(p, aggFuncs, sel.GroupBy)
		}
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
	} else {
		if hasAgg {
			p = b.buildAggregate(p, aggFuncs, nil)
		}
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
	}
	if sel.Having != nil {
		p = b.buildHaving(p, sel.Having)
		if b.err != nil {
			return nil
		}
	}
	if sel.OrderBy != nil && !matchOrder(p, sel.OrderBy.Items) {
		p = b.buildSort(p, sel.OrderBy.Items)
		if b.err != nil {
			return nil
		}
	}
	if sel.Limit != nil {
		p = b.buildLimit(p, sel.Limit)
		if b.err != nil {
			return nil
		}
	}
	return p
}
开发者ID:xudongQiu,项目名称:tidb,代码行数:57,代码来源:planbuilder.go

示例3: selectStmt

func (v *typeInferrer) selectStmt(x *ast.SelectStmt) {
	rf := x.GetResultFields()
	for _, val := range rf {
		// column ID is 0 means it is not a real column from table, but a temporary column,
		// so its type is not pre-defined, we need to set it.
		if val.Column.ID == 0 && val.Expr.GetType() != nil {
			val.Column.FieldType = *(val.Expr.GetType())
		}
	}
}
开发者ID:yuanfeng0905,项目名称:tidb,代码行数:10,代码来源:typeinferer.go

示例4: detectSelectAgg

// Detect aggregate function or groupby clause.
func (b *planBuilder) detectSelectAgg(sel *ast.SelectStmt) bool {
	if sel.GroupBy != nil {
		return true
	}
	for _, f := range sel.GetResultFields() {
		if ast.HasAggFlag(f.Expr) {
			return true
		}
	}
	return false
}
开发者ID:zxylvlp,项目名称:tidb,代码行数:12,代码来源:planbuilder.go

示例5: buildSelect

func (b *planBuilder) buildSelect(sel *ast.SelectStmt) Plan {
	var p Plan
	if sel.From != nil {
		p = b.buildJoin(sel.From.TableRefs)
		if b.err != nil {
			return nil
		}
		if sel.Where != nil {
			p = b.buildFilter(p, sel.Where)
			if b.err != nil {
				return nil
			}
		}
		if sel.LockTp != ast.SelectLockNone {
			p = b.buildSelectLock(p, sel.LockTp)
			if b.err != nil {
				return nil
			}
		}
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
	} else {
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
		if sel.Where != nil {
			p = b.buildFilter(p, sel.Where)
			if b.err != nil {
				return nil
			}
		}
	}
	if sel.OrderBy != nil {
		p = b.buildSort(p, sel.OrderBy.Items)
		if b.err != nil {
			return nil
		}
	}
	if sel.Limit != nil {
		p = b.buildLimit(p, sel.Limit)
		if b.err != nil {
			return nil
		}
	}
	return p
}
开发者ID:lovedboy,项目名称:tidb,代码行数:49,代码来源:planbuilder.go

示例6: extractSelectAgg

// extractSelectAgg extracts aggregate functions and converts ColumnNameExpr to aggregate function.
func (b *planBuilder) extractSelectAgg(sel *ast.SelectStmt) []*ast.AggregateFuncExpr {
	extractor := &ast.AggregateFuncExtractor{AggFuncs: make([]*ast.AggregateFuncExpr, 0)}
	for _, f := range sel.GetResultFields() {
		n, ok := f.Expr.Accept(extractor)
		if !ok {
			b.err = errors.New("Failed to extract agg expr!")
			return nil
		}
		ve, ok := f.Expr.(*ast.ValueExpr)
		if ok && len(f.Column.Name.O) > 0 {
			agg := &ast.AggregateFuncExpr{
				F:    ast.AggFuncFirstRow,
				Args: []ast.ExprNode{ve},
			}
			agg.SetType(ve.GetType())
			extractor.AggFuncs = append(extractor.AggFuncs, agg)
			n = agg
		}
		f.Expr = n.(ast.ExprNode)
	}
	// Extract agg funcs from having clause.
	if sel.Having != nil {
		n, ok := sel.Having.Expr.Accept(extractor)
		if !ok {
			b.err = errors.New("Failed to extract agg expr from having clause")
			return nil
		}
		sel.Having.Expr = n.(ast.ExprNode)
	}
	// Extract agg funcs from orderby clause.
	if sel.OrderBy != nil {
		for _, item := range sel.OrderBy.Items {
			n, ok := item.Expr.Accept(extractor)
			if !ok {
				b.err = errors.New("Failed to extract agg expr from orderby clause")
				return nil
			}
			item.Expr = n.(ast.ExprNode)
			// If item is PositionExpr, we need to rebind it.
			// For PositionExpr will refer to a ResultField in fieldlist.
			// After extract AggExpr from fieldlist, it may be changed (See the code above).
			if pe, ok := item.Expr.(*ast.PositionExpr); ok {
				pe.Refer = sel.GetResultFields()[pe.N-1]
			}
		}
	}
	return extractor.AggFuncs
}
开发者ID:XuHuaiyu,项目名称:tidb,代码行数:49,代码来源:planbuilder.go

示例7: extractSelectAgg

// extractSelectAgg extracts aggregate functions and converts ColumnNameExpr to aggregate function.
func (b *planBuilder) extractSelectAgg(sel *ast.SelectStmt) []*ast.AggregateFuncExpr {
	extractor := &ast.AggregateFuncExtractor{AggFuncs: make([]*ast.AggregateFuncExpr, 0)}
	res := make([]*ast.ResultField, 0, len(sel.GetResultFields()))
	for _, f := range sel.GetResultFields() {
		n, ok := f.Expr.Accept(extractor)
		if !ok {
			b.err = errors.New("Failed to extract agg expr!")
			return nil
		}
		ve, ok := f.Expr.(*ast.ValueExpr)
		if ok && len(f.Column.Name.O) > 0 {
			agg := &ast.AggregateFuncExpr{
				F:    ast.AggFuncFirstRow,
				Args: []ast.ExprNode{ve},
			}
			extractor.AggFuncs = append(extractor.AggFuncs, agg)
			n = agg
		}
		// Clone the ResultField.
		// For "select c from t group by c;" both "c"s in select field and grouby clause refer to the same ResultField.
		// So we should not affact the "c" in groupby clause.
		nf := &ast.ResultField{
			ColumnAsName: f.ColumnAsName,
			Column:       f.Column,
			Table:        f.Table,
			DBName:       f.DBName,
			Expr:         n.(ast.ExprNode),
		}
		res = append(res, nf)
	}
	sel.SetResultFields(res)
	// Extract agg funcs from orderby clause.
	if sel.OrderBy != nil {
		for _, item := range sel.OrderBy.Items {
			n, ok := item.Expr.Accept(extractor)
			if !ok {
				b.err = errors.New("Failed to extract agg expr from orderby clause")
				return nil
			}
			item.Expr = n.(ast.ExprNode)
		}
	}
	// TODO: extract aggfuncs from having clause.
	return extractor.AggFuncs
}
开发者ID:zxylvlp,项目名称:tidb,代码行数:46,代码来源:planbuilder.go

示例8: extractSelectAgg

// extractSelectAgg extracts aggregate functions and converts ColumnNameExpr to aggregate function.
func (b *planBuilder) extractSelectAgg(sel *ast.SelectStmt) []*ast.AggregateFuncExpr {
	extractor := &ast.AggregateFuncExtractor{AggFuncs: make([]*ast.AggregateFuncExpr, 0)}
	res := make([]*ast.ResultField, 0, len(sel.GetResultFields()))
	for _, f := range sel.GetResultFields() {
		n, ok := f.Expr.Accept(extractor)
		if !ok {
			b.err = errors.New("Failed to extract agg expr!")
			return nil
		}
		ve, ok := f.Expr.(*ast.ValueExpr)
		if ok && len(f.Column.Name.O) > 0 {
			agg := &ast.AggregateFuncExpr{
				F:    ast.AggFuncFirstRow,
				Args: []ast.ExprNode{ve},
			}
			extractor.AggFuncs = append(extractor.AggFuncs, agg)
			n = agg
		}
		// Clone the ResultField.
		// For "select c from t group by c;" both "c"s in select field and grouby clause refer to the same ResultField.
		// So we should not affact the "c" in groupby clause.
		nf := &ast.ResultField{
			ColumnAsName: f.ColumnAsName,
			Column:       f.Column,
			Table:        f.Table,
			DBName:       f.DBName,
			Expr:         n.(ast.ExprNode),
		}
		res = append(res, nf)
	}
	sel.SetResultFields(res)
	// Extract agg funcs from having clause.
	if sel.Having != nil {
		n, ok := sel.Having.Expr.Accept(extractor)
		if !ok {
			b.err = errors.New("Failed to extract agg expr from having clause")
			return nil
		}
		sel.Having.Expr = n.(ast.ExprNode)
	}
	// Extract agg funcs from orderby clause.
	if sel.OrderBy != nil {
		for _, item := range sel.OrderBy.Items {
			n, ok := item.Expr.Accept(extractor)
			if !ok {
				b.err = errors.New("Failed to extract agg expr from orderby clause")
				return nil
			}
			item.Expr = n.(ast.ExprNode)
			// If item is PositionExpr, we need to rebind it.
			// For PositionExpr will refer to a ResultField in fieldlist.
			// After extract AggExpr from fieldlist, it may be changed (See the code above).
			if pe, ok := item.Expr.(*ast.PositionExpr); ok {
				pe.Refer = sel.GetResultFields()[pe.N-1]
			}
		}
	}
	return extractor.AggFuncs
}
开发者ID:tutuhuagong,项目名称:tidb,代码行数:60,代码来源:planbuilder.go

示例9: detectSelectAgg

// Detect aggregate function or groupby clause.
func (b *planBuilder) detectSelectAgg(sel *ast.SelectStmt) bool {
	if sel.GroupBy != nil {
		return true
	}
	for _, f := range sel.GetResultFields() {
		if ast.HasAggFlag(f.Expr) {
			return true
		}
	}
	if sel.Having != nil {
		if ast.HasAggFlag(sel.Having.Expr) {
			return true
		}
	}
	if sel.OrderBy != nil {
		for _, item := range sel.OrderBy.Items {
			if ast.HasAggFlag(item.Expr) {
				return true
			}
		}
	}
	return false
}
开发者ID:tutuhuagong,项目名称:tidb,代码行数:24,代码来源:planbuilder.go

示例10: buildSelect

func (b *planBuilder) buildSelect(sel *ast.SelectStmt) Plan {
	// Detect aggregate function or groupby clause.
	aggDetetor := &ast.AggFuncDetector{}
	sel.Accept(aggDetetor)
	var aggFuncs []*ast.AggregateFuncExpr
	if aggDetetor.HasAggFunc {
		extractor := &ast.AggregateFuncExtractor{AggFuncs: make([]*ast.AggregateFuncExpr, 0)}
		// TODO: extract aggfuncs from having clause.
		for _, f := range sel.GetResultFields() {
			f.Expr.Accept(extractor)
			// TODO: check error
		}
		aggFuncs = extractor.AggFuncs
		// TODO: extract aggfuncs from having clause.
	}
	var p Plan
	if sel.From != nil {
		p = b.buildJoin(sel.From.TableRefs)
		if b.err != nil {
			return nil
		}
		if sel.Where != nil {
			p = b.buildFilter(p, sel.Where)
			if b.err != nil {
				return nil
			}
		}
		if sel.LockTp != ast.SelectLockNone {
			p = b.buildSelectLock(p, sel.LockTp)
			if b.err != nil {
				return nil
			}
		}
		if len(aggFuncs) > 0 {
			p = b.buildAggregate(p, aggFuncs)
		}
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
	} else {
		if len(aggFuncs) > 0 {
			p = b.buildAggregate(p, aggFuncs)
		}
		p = b.buildSelectFields(p, sel.GetResultFields())
		if b.err != nil {
			return nil
		}
		if sel.Where != nil {
			p = b.buildFilter(p, sel.Where)
			if b.err != nil {
				return nil
			}
		}
	}
	if sel.OrderBy != nil {
		p = b.buildSort(p, sel.OrderBy.Items)
		if b.err != nil {
			return nil
		}
	}
	if sel.Limit != nil {
		p = b.buildLimit(p, sel.Limit)
		if b.err != nil {
			return nil
		}
	}
	return p
}
开发者ID:MDistribuntedSystem,项目名称:tidb,代码行数:69,代码来源:planbuilder.go


注:本文中的github.com/pingcap/tidb/ast.SelectStmt.GetResultFields方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,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。