func makeDefaultExprs(
cols []sqlbase.ColumnDescriptor, parse *parser.Parser, evalCtx *parser.EvalContext,
) ([]parser.TypedExpr, error) {
// Check to see if any of the columns have DEFAULT expressions. If there
// are no DEFAULT expressions, we don't bother with constructing the
// defaults map as the defaults are all NULL.
haveDefaults := false
for _, col := range cols {
if col.DefaultExpr != nil {
haveDefaults = true
break
}
}
if !haveDefaults {
return nil, nil
}
// Build the default expressions map from the parsed SELECT statement.
defaultExprs := make([]parser.TypedExpr, 0, len(cols))
exprStrings := make([]string, 0, len(cols))
for _, col := range cols {
if col.DefaultExpr != nil {
exprStrings = append(exprStrings, *col.DefaultExpr)
}
}
exprs, err := parser.ParseExprsTraditional(exprStrings)
if err != nil {
return nil, err
}
defExprIdx := 0
for _, col := range cols {
if col.DefaultExpr == nil {
defaultExprs = append(defaultExprs, parser.DNull)
continue
}
expr := exprs[defExprIdx]
typedExpr, err := parser.TypeCheck(expr, nil, col.Type.ToDatumType())
if err != nil {
return nil, err
}
if typedExpr, err = parse.NormalizeExpr(evalCtx, typedExpr); err != nil {
return nil, err
}
defaultExprs = append(defaultExprs, typedExpr)
defExprIdx++
}
return defaultExprs, nil
}
