Std.Db.Query.Part

type

This declaration introduces a public type.

What it does

A statement, and the values that travel beside it.

The text is built only from parts the program wrote. Everything that came

from outside is in values, and there is no call that moves one into the

other — which is what makes an injection unrepresentable here rather than

prevented by a rule someone remembers at every call site.

One piece of a statement: text the program wrote, or the place a value goes.

A placeholder is a part rather than text reading $3, and that is what

makes joining two statements cost nothing. Written into the text, a

placeholder has to be found again and renumbered whenever a statement is

put after another — which means scanning every character of it, on every

join. Kept as a part, the numbers are never written until the text is

asked for, and then they are written once, in order.

Read the signature

• This declaration has no value signature because it introduces a type or trait.