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Columns

The expr.Columns type is a bob expression.

To create a new columns list, use orm.NewColumns(names ...string). You can then add the parent table with WithParent()

orm.NewColumns("id", "name", "email").WithParent("public.users")
-- table_alias.column_name
"public.users"."id" AS "id",
"public.users"."name" AS "name",
"public.users"."email" AS "email"

The View and Table models for a table also include a Columns field embeds a column list with all of the table's columns. In addition, there are several convenience methods to manipulate the columns list.

Only​

Returns the column list with ONLY the given column names.

userView.Columns.Only("email")
"public.users"."email" AS "email",

Except​

Returns the columns list without the given column names.

userView.Columns.Except("email")
"public.users"."id" AS "id",
"public.users"."name" AS "name",

WithParent​

Changes the parent of the column list. For example if selecting with an alias.
Multiple strings are quoted and joined with a dot.

userView.Columns.WithParent("backup", "users_old")
"backup"."users_old"."id" AS "id",
"backup"."users_old"."name" AS "name",
"backup"."users_old"."email" AS "email"

WithPrefix​

Sets a prefix for all columns, useful for joins with duplicate column names.

userView.Columns.WithPrefix("users.")
"public.users"."id" AS "users.id",
"public.users"."name" AS "users.name",
"public.users"."email" AS "users.email"