func (s *selectNode) addRender(target parser.SelectExpr, desiredType parser.Type) error {
// Pre-normalize any VarName so the work is not done twice below.
if err := target.NormalizeTopLevelVarName(); err != nil {
return err
}
if isStar, cols, typedExprs, err := checkRenderStar(target, s.source.info, s.ivarHelper); err != nil {
return err
} else if isStar {
s.columns = append(s.columns, cols...)
s.render = append(s.render, typedExprs...)
s.isStar = true
return nil
}
// When generating an output column name it should exactly match the original
// expression, so determine the output column name before we perform any
// manipulations to the expression.
outputName := getRenderColName(target)
normalized, err := s.planner.analyzeExpr(target.Expr, s.sourceInfo, s.ivarHelper, desiredType, false, "")
if err != nil {
return err
}
s.addRenderColumn(normalized, ResultColumn{Name: outputName, Typ: normalized.ResolvedType()})
return nil
}
// computeRender expands a target expression into a result column (or more
// than one, in case there is a star). Whether star expansion occurred
// is indicated by the third return value.
func (p *planner) computeRender(
target parser.SelectExpr,
desiredType parser.Type,
info *dataSourceInfo,
ivarHelper parser.IndexedVarHelper,
allowStars bool,
) (columns ResultColumns, exprs []parser.TypedExpr, hasStar bool, err error) {
// Pre-normalize any VarName so the work is not done twice below.
if err := target.NormalizeTopLevelVarName(); err != nil {
return nil, nil, false, err
}
if hasStar, cols, typedExprs, err := checkRenderStar(
target, info, ivarHelper, allowStars); err != nil {
return nil, nil, false, err
} else if hasStar {
return cols, typedExprs, hasStar, nil
}
// When generating an output column name it should exactly match the original
// expression, so determine the output column name before we perform any
// manipulations to the expression.
outputName := getRenderColName(target)
normalized, err := p.analyzeExpr(
target.Expr, multiSourceInfo{info}, ivarHelper, desiredType, false, "")
if err != nil {
return nil, nil, false, err
}
return ResultColumns{
ResultColumn{Name: outputName, Typ: normalized.ResolvedType()},
}, []parser.TypedExpr{normalized}, false, nil
}