本文整理汇总了Golang中github.com/pingcap/tidb/ast.PositionExpr类的典型用法代码示例。如果您正苦于以下问题：Golang PositionExpr类的具体用法？Golang PositionExpr怎么用？Golang PositionExpr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PositionExpr类的4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: handlePosition
func (nr *nameResolver) handlePosition(pos *ast.PositionExpr) {
ctx := nr.currentContext()
if pos.N < 1 || pos.N > len(ctx.fieldList) {
nr.Err = errors.Errorf("Unknown column '%d'", pos.N)
return
}
pos.Refer = ctx.fieldList[pos.N-1]
}示例2: handlePosition
func (nr *nameResolver) handlePosition(pos *ast.PositionExpr) {
ctx := nr.currentContext()
if pos.N < 1 || pos.N > len(ctx.fieldList) {
nr.Err = errors.Errorf("Unknown column '%d'", pos.N)
return
}
pos.Refer = ctx.fieldList[pos.N-1]
if nr.currentContext().inGroupBy {
// make sure item is not aggregate function
if ast.HasAggFlag(pos.Refer.Expr) {
nr.Err = errors.New("group by cannot contain aggregate function")
}
}
}示例3: handlePosition
func (nr *nameResolver) handlePosition(pos *ast.PositionExpr) {
ctx := nr.currentContext()
if pos.N < 1 || pos.N > len(ctx.fieldList) {
nr.Err = errors.Errorf("Unknown column '%d'", pos.N)
return
}
matched := ctx.fieldList[pos.N-1]
nf := *matched
expr := matched.Expr
if cexpr, ok := expr.(*ast.ColumnNameExpr); ok {
expr = cexpr.Refer.Expr
}
nf.Expr = expr
pos.Refer = &nf
if nr.currentContext().inGroupBy {
// make sure item is not aggregate function
if ast.HasAggFlag(pos.Refer.Expr) {
nr.Err = errors.New("group by cannot contain aggregate function")
}
}
}示例4: position
func (e *Evaluator) position(v *ast.PositionExpr) bool {
v.SetDatum(*v.Refer.Expr.GetDatum())
return true
}