Function findColumnForRef

internal/compiler/output_columns.go:725–779

(ref *ast.ColumnRef, tables []*Table, targetList *ast.List)

}

func findColumnForRef(ref *ast.ColumnRef, tables []*Table, targetList *ast.List) error {
	parts := stringSlice(ref.Fields)
	var alias, name string
	if len(parts) == 1 {
		name = parts[0]
	} else if len(parts) == 2 {
		alias = parts[0]
		name = parts[1]
	}

	var found int
	for _, t := range tables {
		if alias != "" && t.Rel.Name != alias {
			continue
		}

		// Find matching column
		for _, c := range t.Columns {
			if c.Name == name {
				found++
				break
			}
		}
	}

	// Find matching alias if necessary
	if found == 0 {
		for _, c := range targetList.Items {
			resTarget, ok := c.(*ast.ResTarget)
			if !ok {
				continue
			}
			if resTarget.Name != nil && *resTarget.Name == name {
				found++
			}
		}
	}

	if found == 0 {
		return &sqlerr.Error{
			Code:     "42703",
			Message:  fmt.Sprintf("column reference %q not found", name),
			Location: ref.Location,
		}
	}
	if found > 1 {
		return &sqlerr.Error{
			Code:     "42703",
			Message:  fmt.Sprintf("column reference %q is ambiguous", name),
			Location: ref.Location,
		}
	}

	return nil
}